01. Pediatric fractures of the upper extremity

Pediatric fractures of the shoulder girdle and upper extremity. Features of diagnosis and treatment. Main principles of no operative and operative treatment in children depending on age. Principles of rehabilitation.

.

 

 

Pediatric Shoulder

 

PROXIMAL HUMERUS FRACTURES

Epidemiology

• These account for <5% of fractures in children.

• Incidence ranges from 1.2 to 4.4 per 10,000 per year.

• They are most common in adolescents owing to increased sports participation and are often metaphyseal, physeal, or both.

• Neonates may sustain birth trauma to the proximal humeral physis, representing 1.9% to 6.7% of physeal injuries (Fig. 1).

 

Figure 1. Hyperextension or rotation of the ipsilateral arm may result in a proximal humeral or physeal injury during birth. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Greenв’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

Anatomy

• Eighty percent of humeral growth occurs at the proximal physis, giving this region great remodeling potential.

• There are three centers of ossification in the proximal humerus:

• Humeral head: This ossifies at 6 months.

• Greater tuberosity: This ossifies at 1 to 3 years.

• Lesser tuberosity: This ossifies at 4 to 5 years.

• The greater and lesser tuberosities coalesce at 6 to 7 years and then fuse with the humeral head between 7 and 13 years of age.

• The joint capsule extends to the metaphysis, rendering some fractures of the metaphysis intracapsular (Fig. 2).

 

 

 

 

 

Figure 2. The anatomy of the proximal humerus. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• The primary vascular supply is via the anterolateral ascending branch of the anterior circumflex artery, with a small portion of the greater tuberosity and inferior humeral head supplied by branches from the posterior circumflex artery.

• The physis closes at age 14 to 17 years in girls and at age 16 to 18 years in boys.

• The physeal apex is posteromedial and is associated with a strong, thick periosteum.

• Type I physeal fractures occur through the hypertrophic zone adjacent to the zone of provisional calcification. The layer of embryonal cartilage is preserved, leading to normal growth.

• Muscular deforming forces: The subscapularis attaches to lesser tuberosity. The remainder of the rotator cuff (teres minor, supraspinatus, and infraspinatus) attaches to posterior epiphysis and greater tuberosity. The pectoralis major attaches to anterior medial metaphysis, and the deltoid connects to the lateral shaft.

Mechanism of Injury

• Indirect: This results from a fall backward onto an outstretched hand with the elbow extended and the wrist dorsiflexed. Birth injuries may occur as the arm is hyperextended or rotated as the infant is being delivered. Shoulder dystocia is strongly associated with macrosomia from maternal diabetes.

• Direct: Direct trauma to the posterolateral aspect of the shoulder can occur.

Clinical Evaluation

• Newborns present with pseudoparalysis with the arm held in extension. A history of birth trauma may be elicited. A fever is variably present. Infection, clavicle fracture, shoulder dislocation, and brachial plexus injury must be ruled out.

• Older children present with pain, dysfunction, swelling, and ecchymosis, and the humeral shaft fragment may be palpable anteriorly. The shoulder is tender to palpation, with a painful range of motion that may reveal crepitus.

• Typically, the arm is held in internal rotation to prevent pull of the pectoralis major on the distal fragment.

• A careful neurovascular examination is required, including the axillary, musculocutaneous, radial, ulnar, and mediaerves.

• Anteroposterior (AP), lateral (in the plane of the scapula; “Y” view), and axillary views should be obtained, with comparison views of the opposite side if necessary.

• Ultrasound: This may be necessary in the newborn because the epiphysis is not yet ossified.

• Computed tomography may be useful to help diagnose and classify posterior dislocations and complex fractures.

• Magnetic resonance imaging is more useful than bone scan to detect occult fractures because the physis normally has increased radionuclide uptake, making a bone scan difficult to interpret.

Radiographic Evaluation

 

Classification

 

Salter-Harris (Fig. 3)

Figure 3. Physeal fractures of the proximal humerus. (A) Salter-Harris I. (B) Salter-Harris II. (C) Salter-Harris III. (D) Salter-Harris IV. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

 

Type I:	Separation through the physis; usually a birth injury
Type II:	Usually occurring in adolescents (>12 years); metaphyseal fragment always posteromedial
Type III:	Intraarticular fracture; uncommon; associated with dislocations
Type IV:	Rare; intraarticular transmetaphyseal fracture; associated with open fractures

Neer-Horowitz Classification of Proximal Humeral Plate Fractures

Grade I:	<5 mm displacement
Grade II:	Displacement less than one-third the width of the shaft
Grade III:	Displacement one-third to two-thirds the width of the shaft
Grade IV:	Displacement greater than two-thirds the width of the shaft, including total displacement

 

 

Treatment

 

Treatment depends on the age of the patient as well as the fracture pattern.

Newborns

• Most fractures are Salter-Harris type I. The prognosis is excellent.

• Ultrasound can be used to guide reduction.

• Closed reduction: This is the treatment of choice and is achieved by applying gentle traction, 90 degrees of flexion, then 90 degrees of abduction and external rotation.

• Stable fracture: The arm is immobilized against the chest for 5 to 10 days.

• Unstable fracture: The arm is held abducted and is externally rotated for 3 to 4 days to allow early callus formation.

Ages 1 to 4 Years

• These are typically Salter-Harris type I or, less frequently, type II.

• Treatment is by closed reduction.

• The arm is held in a sling for 10 days followed by progressive activity.

• Extensive remodeling is possible.

Ages 5 to 12 Years

• The metaphyseal fracture (type II) is the most common in this age group, because this area is undergoing the most rapid remodeling and is therefore structurally vulnerable.

• Treatment is by closed reduction.

• Stable fracture: A sling and swathe is used (Fig. 4).

• Unstable fracture: The arm is placed in a shoulder spica cast with the arm in the salute position for 2 to 3 weeks, after which the patient may be placed in a sling, with progressive activity.

 

Figure 4. Sling and swathe for immobilization of proximal humeral fracture. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Ages 12 years to Maturity

• These are either Salter-Harris type II or, less frequently, type I.

• Treatment is by closed reduction.

• There is less remodeling potential than in younger children.

• Stable fracture: A sling and swathe is used for 2 to 3 weeks followed by progressive range-of-motion exercises.

• Unstable fracture and Salter Harris type IV: Immobilization is maintained in a shoulder spica cast with the arm in the salute position for 2 to 3 weeks, after which the patient may be placed in a sling, with progressive activity.

• One should consider surgical stabilization for displaced fractures in adolescents.

Acceptable Deformity

 

Age 1 to 4 years:	70 degrees of angulation with any amount of displacement
Age 5 to 12 years:	40 to 45 degrees of angulation and displacement of one-half the width of the shaft
Age 12 years to maturity:	15 to 20 degrees of angulation and displacement of <30% the width of the shaft

Open Treatment

 

• Indications for open reduction and internal fixation include:

• Open fractures.

• Fractures with associated neurovascular compromise.

• Salter-Harris type III and IV fractures with displacement.

• Irreducible fractures with soft tissue interposition (biceps tendon).

• In children, fixation is most often achieved with percutaneous, smooth Kirschner wires or Steinmann pins.

Prognosis

• Neer-Horowitz grade I and II fractures do well because of the remodeling potential of the proximal humeral physis.

• Neer-Horowitz grade III and IV fractures may be left with up to 3 mm of shortening or residual angulation. This is well tolerated by the patient and is often clinically insignificant.

• As a rule, the younger the patient, the higher the potential for remodeling and the greater the acceptable initial deformity.

 

Complications

• Proximal humerus varus: Rare, usually affecting patients less than 1 year of age, but it may complicate fractures in patients as old as 5 years of age. It may result in a decrease of the neck-shaft angle to 90 degrees with humeral shortening and mild to moderate loss of glenohumeral abduction. Remodeling potential is great in this age group, however, so observation alone may result in improvement. Proximal humeral osteotomy may be performed in cases of extreme functional limitation.

• Limb length inequality: Rarely significant and tends to occur more commonly in surgically treated patients as opposed to those treated nonoperatively.

• Loss of motion: Rare and tends to occur more commonly in surgically treated patients. Older children tend to have more postfracture difficulties with shoulder stiffness than younger children.

• Inferior glenohumeral subluxation: May complicate patients with Salter-Harris Type II fractures of the proximal humerus secondary to a loss of deltoid and rotator cuff tone. It may be addressed by a period of immobilization followed by rotator cuff strengthening exercises.

• Osteonecrosis: May occur with associated disruption of the anterolateral ascending branch of the anterior circumflex artery, especially in fractures or dislocations that are not acutely reduced.

• Nerve injury: Most commonly axillary nerve injury in fracture-dislocations. Lesions that do not show signs of recovery in 4 months should be explored.

• Growth arrest: May occur when the physis is crushed or significantly displaced or when a physeal bar forms. It may require excision of the physeal bar. Limb lengthening may be required for functional deficits or severe cosmetic deformity.

CLAVICLE FRACTURES

Epidemiology

• Most frequent fracture in children (8% to 15% of all pediatric fractures).

• It occurs in 0.5% of normal deliveries and in 1.6% of breech deliveries (accounts for 90% of obstetric fractures).

• In macrosomic infants (>4,000 g), the incidence is 13%.

• Eighty percent of clavicle fractures occur in the shaft, most frequently just lateral to the insertion of the subclavius muscle, which protects the underlying neurovascular structures.

• Ten to 15% of clavicle fractures involve the lateral aspect, with the remainder representing medial fractures.

Anatomy

• The clavicle is the first bone to ossify; this occurs by intramembranous ossification.

• The secondary centers develop via endochondral ossification:

• The medial epiphysis, where 80% of growth occurs, ossifies at age 12 to 19 years and fuses by age 22 to 25 years (last bone to fuse).

• The lateral epiphysis does not ossify until it fuses at age 19 years.

• Clavicular range of motion involves rotation about its long axis (approximately 50 degrees) accompanied by elevation of 30 degrees with full shoulder abduction and 35 degrees of anterior-posterior angulation with shoulder protraction and retraction.

• The periosteal sleeve always remains in the anatomic position. Therefore, remodeling is ensured.

Mechanism of Injury

• Indirect: Fall onto an outstretched hand.

• Direct: This is the most common mechanism, resulting from direct trauma to the clavicle or acromion; it carries the highest incidence of injury to the underlying neurovascular and pulmonary structures.

• Birth injury: Occurs during delivery of the shoulders through a narrow pelvis with direct pressure from the symphysis pubis or from obstetric pressure directly applied to the clavicle during delivery.

• Medial clavicle fractures or dislocations usually represent Salter-Harris type I or II fractures. True sternoclavicular joint dislocations are rare. The inferomedial periosteal sleeve remains intact and provides a scaffold for remodeling. Because 80% of the growth occurs at the medial physis, there is great potential for remodeling.

• Lateral clavicle fractures occur as a result of direct trauma to the acromion. The coracoclavicular ligaments always remain intact and are attached to the inferior periosteal tube. The acromioclavicular ligament is always intact and is attached to the distal fragment.

Clinical Evaluation

• Birth fractures of the clavicle are usually obvious, with an asymmetric, palpable mass overlying the fractured clavicle. An asymmetric Moro reflex is usually present. Nonobvious injuries may be misdiagnosed as congenital muscular torticollis because the patient will often turn his or her head toward the fracture to relax the sternocleidomastoid muscle.

• Children with clavicle fractures typically present with a painful, palpable mass along the clavicle. Tenderness is usually discrete over the site of injury, but it may be diffuse in cases of plastic bowing. There may be tenting of the skin, crepitus, and ecchymosis.

• Neurovascular status must be carefully evaluated because injuries to the brachial plexus and upper extremity vasculature may result.

• Pulmonary status must be assessed, especially if direct trauma is the mechanism of injury. Medial clavicular fractures may be associated with tracheal compression, especially with severe posterior displacement.

• Differential diagnosis

• Cleidocranial dysostosis: This defect in intramembranous ossification, most commonly affecting the clavicle, is characterized by absence of the distal end of the clavicle, a central defect, or complete absence of the clavicle. Treatment is symptomatic only.

• Congenital pseudarthrosis: This most commonly occurs at the junction of the middle and distal thirds of the right clavicle, with smooth, pointed bone ends. Pseudarthrosis of the left clavicle is found only in patients with dextrocardia. Patients present with no antecedent history of trauma, only a palpable bump. Treatment is supportive only, with bone grafting and intramedullary fixation reserved for symptomatic cases.

Radiographic Evaluation

• Ultrasound evaluation may be used in the diagnosis of clavicular fracture ieonates.

• Because of the S-shape of the clavicle, an AP view is usually sufficient for diagnostic purposes; however, special views have been described in cases in which a fracture is suspected but not well visualized on a standard AP view (Fig. 5):

Figure 5. (A) Cephalic tilt views. (B) Apical lordotic view. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Cephalic tilt view (cephalic tilt of 35 to 40 degrees): This minimizes overlapping structures to better show degree of displacement.

• Apical oblique view (injured side rotated 45 degrees toward tube with a cephalic tilt of 20 degrees): This is best for visualizing nondisplaced middle third fractures.

• Patients with difficulty breathing should have an AP radiograph of the chest to evaluate possible pneumothorax or associated rib fractures.

• Computed tomography may be useful for the evaluation of medial clavicular fractures or suspected dislocation, because most represent Salter-Harris Type I or II fractures rather than true dislocations.

Classification

Descriptive

• Location

• Open versus closed

• Displacement

• Angulation

• Fracture type: segmental, comminuted, greenstick, etc.

Allman (Fig. 6)

 

Type I:	Middle third (most common)
Type II:	Distal to the coracoclavicular ligaments (lateral third)
Type III:	Proximal (medial) third

 

 

Figure 6. (A) Fracture of the medial third of the clavicle. (B) Fracture of the middle third of the clavicle. (C) Fracture of the lateral third of the clavicle. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

 

Treatment

Newborn to Age 2 Years

• Complete fracture in patients less than 2 years of age is unusual and may be caused by birth injury.

• Clavicle fracture in a newborn will unite in approximately 1 week. Reduction is not indicated. Care with lifting and/or a soft bandage may be used.

• Infants may be treated symptomatically with a simple sling or figure-of-eight bandage applied for 2 to 3 weeks or until the patient is comfortable. One may also pin the sleeve of a long-sleeved shirt to the contralateral shoulder.

Age 2 to 12 Years

• A figure-of-eight bandage or sling is indicated for 2 to 4 weeks, at which time union is complete.

 

Age 12 Years to Maturity

• The incidence of complete fracture is higher.

• A figure-of-eight bandage or sling is used for 3 to 4 weeks. However, figure-of-eight bandages are often poorly tolerated and have been associated with ecchymosis, compression of axillary vessels, and brachial plexopathy.

• If the fracture is grossly displaced with tenting of the skin, one should consider closed or open reduction with or without internal fixation.

Open Treatment

• Operative treatment is indicated in open fractures and those with neurovascular compromise.

• Comminuted fragments that tent the skin may be manipulated and the dermis released from the bone ends with a towel clip. Typically, bony fragments are placed in the periosteal sleeve and the soft tissue repaired. One can also consider internal fixation.

• Bony prominences from callus will usually remodel; exostectomy may be performed at a later date if necessary, although from a cosmetic standpoint the surgical scar is often more noticeable than the prominence.

Complications

• Neurovascular compromise: Rare in children because of the thick periosteum that protects the underlying structures, although brachial plexus and vascular injury (subclavian vessels) may occur with severe displacement.

• Malunion: Rare because of the high remodeling potential; it is well tolerated when present, and cosmetic issues of the bony prominence are the only long-term issue.

• Nonunion: Rare (1% to 3%); it is probably associated with a congenital pseudoarthrosis; it never occurs <12 years of age.

• Pulmonary injury: Rare injuries to the apical pulmonary parenchyma with pneumothorax may occur, especially with severe, direct trauma in an anterosuperior to posteroinferior direction.

ACROMIOCLAVICULAR JOINT INJURIES

Epidemiology

• Rare in children less than 16 years of age.

• The true incidence is unknown because many of these injuries actually represent pseudodislocation of the acromioclavicular joint.

Anatomy

• The acromioclavicular joint is a diarthrodial joint; in mature individuals, an intraarticular disc is present.

• The distal clavicle is surrounded by a thick periosteal sleeve that extends to the acromioclavicular joint.

Mechanism of Injury

• Athletic injuries and falls comprise the majority of acromioclavicular injuries, with direct trauma to the acromion.

• Unlike acromioclavicular injuries in adults, in children the coracoclavicular (conoid and trapezoid) ligaments remain intact. Because of the tight approximation of the coracoclavicular ligaments to the periosteum of the distal clavicle, true dislocation of the acromioclavicular joint is rare.

• The defect is a longitudinal split in the superior portion of the periosteal sleeve through which the clavicle is delivered, much like a banana being peeled from its skin.

Clinical Evaluation

• The patient should be examined while in the standing or sitting position to allow the upper extremity to be dependent, thus stressing the acromioclavicular joint and emphasizing deformity.

• A thorough shoulder examination should be performed, including assessment of neurovascular status and possible associated upper extremity injuries. Inspection may reveal an apparent step-off deformity of the injured acromioclavicular joint, with possible tenting of the skin overlying the distal clavicle. Range of motion may be limited by pain. Tenderness may be elicited over the acromioclavicular joint.

Radiographic Evaluation

• A standard trauma series of the shoulder (AP, scapular-Y, and axillary views) is usually sufficient for the recognition of acromioclavicular injury, although closer evaluation includes targeted views of the AC joint, which requires one-third to one-half the radiation to avoid overpenetration.

• Ligamentous injury may be assessed via stress radiographs, in which weights (5 to 10 lb) are strapped to the wrists and an AP radiograph is taken of both shoulders for comparison.

Classification (Dameron and Rockwood) (Fig. 7)

 

Type I:	Mild sprain of the acromioclavicular ligaments without periosteal tube disruption; distal clavicle stable to examination and no radiographic abnormalities
Type II:	Partial disruption of the periosteal tube with mild distal clavicle instability; slight widening of the acromioclavicular space appreciated on radiographs
Type III:	Longitudinal split of the periosteal tube with gross instability of the distal clavicle to examination; superior displacement of 25% to 100% present on radiographs as compared with the normal, contralateral shoulder
Type IV:	Posterior displacement of the distal clavicle through a periosteal sleeve disruption with buttonholing through the trapezius; AP radiographs demonstrating superior displacement similar to type II injuries, but axillary radiographs demonstrating posterior displacement
Type V:	Type III injury with >100% displacement; distal clavicle may be subcutaneous to palpation, with possible disruption of deltoid or trapezial attachments
Type VI:	Infracoracoid displacement of the distal clavicle as a result of a superior-to-inferior force vector

 

Figure 7. Dameron and Rockwood classification of distal/lateral fractures. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Treatment

• For Types I to III, nonoperative treatment is indicated, with sling immobilization, ice, and early range-of-motion exercises as pain subsides. Remodeling is expected. Complete healing generally takes place in 4 to 6 weeks.

• Treatment for Types IV to VI is operative, with reduction of the clavicle and repair of the periosteal sleeve. Internal fixation may be needed.

Complications

• Neurovascular injury: This is rare and is associated with posteroinferior displacement. The intact periosteal sleeve is thick and usually provides protection to neurovascular structures underlying the distal clavicle.

• Open lesion: Severe displacement of the distal clavicle, such as with Type V acromioclavicular dislocation, may result in tenting of the skin, with possible laceratioecessitating irrigation and debridement.

SCAPULA FRACTURES

• The scapula is relatively protected from trauma by the thoracic cavity and the rib cage anteriorly as well as by the encasing musculature.

• Scapular fractures are often associated with other life-threatening injuries that have greater priority.

Epidemiology

• These constitute only 1% of all fractures and 5% of shoulder fractures in the general population and are even less common in children.

Anatomy

• The scapula forms from intramembranous ossification. The body and spine are ossified at birth.

• The center of the coracoid is ossified at 1 year. The base of the coracoid and the upper one-fourth of the glenoid ossify by 10 years. A third center at the tip of the coracoid ossifies at a variable time. All three structures fuse by age 15 to 16 years.
• The acromion fuses by age 22 years via two to five centers, which begin to form at puberty.

• Centers for the vertebral border and inferior angle appear at puberty and fuse by age 22 years. The center for the lower three-fourths of the glenoid appears at puberty and fuses by age 22 years.

• The suprascapular nerve traverses the suprascapular notch on the superior aspect of the scapula, medial to the base of the coracoid process, thus rendering it vulnerable to fractures in this region.

• The superior shoulder suspensory complex (SSSC) is a circular group of both bony and ligamentous attachments (acromion, glenoid, coracoid, coracoclavicular ligament, and distal clavicle). The integrity of the ring is breached only after more than one violation. This can dictate the treatment approach (Fig. 8).

Figure 8. Superior shoulder suspensory complex. (A) Anteroposterior view of the bone–soft tissue ring and superior and inferior bone struts. (B) Lateral view of the bone–soft tissue ring. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Mechanism of Injury

• In children, most scapula fractures represent avulsion fractures associated with glenohumeral joint injuries. Other fractures are usually the result of high-energy trauma.

• Isolated scapula fractures are extremely uncommon, particularly in children; child abuse should be suspected unless a clear and consistent mechanism of injury exists.

• The presence of a scapula fracture should raise suspicion of associated injuries, because 35% to 98% of scapula fractures occur in the presence of other injuries including:

• Ipsilateral upper torso injuries: fractured ribs, clavicle, sternum, shoulder trauma.

• Pneumothorax: seen in 11% to 55% of scapular fractures.

•  

• Pulmonary contusion: present in 11% to 54% of scapula fractures.

• Injuries to neurovascular structures: brachial plexus injuries, vascular avulsions.

• Spinal column injuries: 20% lower cervical spine, 76% thoracic spine, 4% lumbar spine.

• Others: concomitant skull fractures, blunt abdominal trauma, pelvic fracture, and lower extremity injuries, which are all seen with higher incidences in the presence of a scapula fracture.

• Rate of mortality in setting of scapula fractures may approach 14%.

Clinical Evaluation

• Full trauma evaluation, with attention to airway, breathing, circulation, disability, and exposure should be performed, if indicated.

• Patients typically present with the upper extremity supported by the contralateral hand in an adducted and immobile positions, with painful range of shoulder motion, especially with abduction.

• A careful examination for associated injures should be pursued, with a comprehensive assessment of neurovascular status and an evaluation of breath sounds.

Radiographic Evaluation

• Initial radiographs should include a trauma series of the shoulder, consisting of true AP, axillary, and scapular-Y (true scapular lateral) views; these generally are able to demonstrate most glenoid, neck, body, and acromion fractures.

• The axillary view may be used to delineate acromial and glenoid rim fractures further.

• An acromial fracture should not be confused with an os acromiale, which is a rounded, unfused apophysis at the epiphyseal level and is present in approximately 3% of the population. When present, it is bilateral in 60% of cases. The os is typically in the anteroinferior aspect of distal acromion.

• Glenoid hypoplasia, or scapular neck dysplasia, is an unusual abnormality that may resemble glenoid impaction and may be associated with humeral head or acromial abnormalities. It has a benign course and is usually noted incidentally.

• A 45-degree cephalic tilt (Stryker notch) radiograph is helpful to identify coracoid fractures.

• Computed tomography may be useful for further characterizing intraarticular glenoid fractures.

• Because of the high incidence of associated injuries, especially to thoracic structures, a chest radiograph is an essential part of the evaluation.

Classification

 

Classification by Location

 

BODY (35%) AND NECK (27%) FRACTURES

I.	Isolated versus associated disruption of the clavicle
II.	Displaced versus nondisplaced

 

GLENOID FRACTURES (IDEBERG AND GOSS) (FIG. 9)

IA:	Anterior avulsion fracture
IB:	Posterior rim avulsion
II:	Transverse with inferior free fragment
III:	Upper third including coracoid
IV	Horizontal fracture extending through body
V:	Combined II, III, and IV
VI:	Extensively comminuted

•  

Figure 9. General classification of scapular/glenoid fractures. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• These can be associated with scapular neck fractures and shoulder dislocations.

• Treatment is nonoperative in most cases. Open reduction and internal fixation are indicated if a large anterior or posterior rim fragment is associated with glenohumeral instability.

CORACOID FRACTURES

These are isolated versus associated disruption of the acromioclavicular joint.

• These are avulsion-type injuries, usually occurring through the common physis of the base of the coracoid and the upper one-fourth of the glenoid.

• The coracoacromial ligament remains intact, but the acromioclavicular ligaments may be stretched.

ACROMIAL FRACTURES

 

I:	Nondisplaced
IA:	Avulsion
IB:	Direct trauma
II:	Displaced without subacromial narrowing
III:	Displaced with subacromial narrowing

 

• These are rare, usually the result of a direct blow

• The os acromiale, which is an unfused ossification center, should not be mistaken for a fracture.

• Conservative treatment is recommended unless there is severe displacement of the acromioclavicular joint.

Treatment

• Scapula body fractures in children are treated nonoperatively, with the surrounding musculature maintaining reasonable proximity of fracture fragments. Operative treatment is indicated for fractures that fail to unite, which may benefit from partial body excision.

• Scapula neck fractures that are nondisplaced and not associated with clavicle fractures may be treated nonoperatively. Significantly displaced fractures may be treated in a thoracobrachial
  cast. Associated clavicular disruption, either by fracture or ligamentous instability (i.e., multiple disruptions in the SSSC) are generally treated operatively with open reduction and internal fixation of the clavicle alone or include open reduction and internal fixation of the scapula fracture though a separate incision.

• Coracoid fractures that are nondisplaced may be treated with sling immobilization. Displaced fractures are usually accompanied by acromioclavicular dislocation or lateral clavicular injury and should be treated with open reduction and internal fixation.

• Acromial fractures that are nondisplaced may be treated with sling immobilization. Displaced acromial fractures with associated subacromial impingement should be reduced and stabilized with screw or plate fixation.

• Glenoid fractures in children, if not associated with glenohumeral instability, are rarely symptomatic when healed and can generally be treated nonoperatively if they are nondisplaced.

Type I:	Fractures involving greater than one fourth of the glenoid fossa that result in instability may be amenable to open reduction and lag screw fixation.
Type II:	Inferior subluxation of the humeral head may result, necessitating open reduction, especially when associated with a greater than 5 mm articular step-off. An anterior approach usually provides adequate exposure.
Type III:	Reduction may be difficult; fracture occurs through the junction between the ossification centers of the glenoid and are often accompanied by a fractured acromion or clavicle, or an acromioclavicular separation. Open reduction and internal fixation followed by early range of motion are indicated.
Types IV, V, VI:	These are difficult to reduce, with little bone stock for adequate fixation in pediatric patients. A posterior approach is generally utilized for open reduction and internal fixation with Kirschner wire, plate, suture, or screw fixation for displaced fractures.

Complications

• Posttraumatic osteoarthritis: This may result from a failure to restore articular congruity.

• Associated injuries: These account for most serious complications because of the high-energy nature of these injuries.

• Decreased shoulder motion: Secondary to subacromial impingement from acromial fracture.

• Malunion: Fractures of the scapula body generally unite with nonoperative treatment; when malunion occurs, it is generally well tolerated but may result in painful scapulothoracic crepitus.

• Nonunion: Extremely rare, but when present and symptomatic it may require open reduction and plate fixation for adequate relief.

• Suprascapular nerve injury: May occur in association with scapula body, scapula neck, or coracoid fractures that involve the suprascapular notch.

GLENOHUMERAL DISLOCATIONS

Epidemiology

• Rare in children; Rowe reported that only 1.6% of shoulder dislocations occurred in patients <10 years of age, whereas 10% occurred in patients 10 to 20 years of age.

• Ninety percent are anterior dislocations.

Anatomy

• The glenohumeral articulation, with its large convex humeral head and correspondingly flat glenoid, is ideally suited to accommodate a wide range of shoulder motion. The articular surface and radius of curvature of the humeral head are about three times those of the glenoid fossa.

• Numerous static and dynamic stabilizers of the shoulder exist; these are covered in detail in Chapter 14.

• The humeral attachment of the glenohumeral joint capsule is along the anatomic neck of the humerus except medially, where the attachment is more distal along the shaft. The proximal humeral physis is therefore extraarticular except along its medial aspect.

• As in most pediatric joint injuries, the capsular attachment to the epiphysis renders failure through the physis much more common than true capsuloligamentous injury; therefore, fracture through the physis is more common than a shoulder dislocation in a skeletally immature patient.

• Ieonates, an apparent dislocation may actually represent a physeal injury.

Mechanism of Injury

• Neonates: Pseudodislocation may occur with traumatic epiphyseal separation of the proximal humerus. This is much more common than a true shoulder dislocation, which may occur ieonates with underlying birth trauma to the brachial plexus or central nervous system.

• Anterior glenohumeral dislocation may occur as a result of trauma, either direct or indirect.

• Direct: An anteriorly directed impact to the posterior shoulder may produce an anterior dislocation.

• Indirect: Trauma to the upper extremity with the shoulder in abduction, extension, and external rotation is the most common mechanism for anterior shoulder dislocation.

• Posterior glenohumeral dislocation (2% to 4%):

• Direct trauma: This results from force application to the anterior shoulder, forcing the humeral head posteriorly.

• Indirect trauma: This is the most common mechanism

• The shoulder typically is in the position of adduction, flexion, and internal rotation at the time of injury with axial loading.

• Electric shock or convulsive mechanisms may produce posterior dislocation owing to the overwhelming of the external rotators of the shoulder (infraspinatus and teres minor muscles) by the internal rotators (latissimus dorsi, pectoralis major, and subscapularis muscles).

• Atraumatic dislocations: Recurrent instability related to congenital or acquired laxity or volitional mechanisms may result in anterior dislocation with minimal trauma.

Clinical Evaluation

• Patient presentation varies according to the type of dislocation encountered.

Anterior Dislocation

• The patient typically presents with the affected upper extremity held in slight abduction and external rotation. The acutely dislocated shoulder is painful, with muscular spasm in an attempt to stabilize the joint.

• Examination typically reveals squaring of the shoulder caused by a relative prominence of the acromion, a relative hollow beneath the acromion posteriorly, and a palpable mass anteriorly.

• A careful neurovascular examination is important with attention to axillary nerve integrity. Deltoid muscle testing is usually not possible, but sensation over the deltoid may be assessed. Deltoid atony may be present and should not be confused with axillary nerve injury. Musculocutaneous nerve integrity can be assessed by the presence of sensation on the anterolateral forearm.

• Patients may present after spontaneous reduction or reduction in the field. If the patient is not in acute pain, examination may reveal a positive apprehension test, in which passive placement of the shoulder in the provocative position (abduction, extension, and external rotation) reproduces the patient’s sense of instability and pain. Posteriorly directed counterpressure over the anterior shoulder may mitigate the sensation of instability.

Posterior Dislocation

• Clinically, a posterior glenohumeral dislocation does not present with striking deformity; moreover, the injured upper extremity is typically held in the traditional sling position of shoulder internal rotation and adduction.

• A careful neurovascular examination is important to rule out axillary nerve injury, although it is much less common than with anterior glenohumeral dislocations.

• On examination, limited external rotation (often <0 degrees) and limited anterior forward elevation (often <90 degrees) may be appreciated.

• A palpable mass posterior to the shoulder, flattening of the anterior shoulder, and coracoid prominence may be observed.

Atraumatic Dislocation

• Patients present with a history of recurrent dislocations with spontaneous reduction.

• Often the patient will report a history of minimal trauma or volitional dislocation, frequently without pain.

• Multidirectional instability may be present bilaterally, as may characteristics of multiple joint laxity, including hyperextensibility of the elbows, knees, and metacarpophalangeal joints. Skin striae may be present.

• Sulcus sign: This is dimpling of skin below the acromion with longitudinal traction.

Superior and Inferior (Luxatio Erecta) Dislocation

• This is extremely rare in children, although cases have been reported.

• It may be associated with hereditary conditions such as Ehlers-Danlos syndrome.

Radiographic Evaluation

• A trauma series of the affected shoulder is indicated: AP, scapular-Y, and axillary views.

• Velpeau axillary view: Compliance is frequently an issue in the irritable, injured child in pain. If a standard axillary view cannot be obtained, the patient may be left in a sling and leaned obliquely backward 45 degrees over the cassette. The beam is directed caudally, orthogonal to the cassette, resulting in an axillary view with magnification.

• Special views (See Chapter 14):

• West Point axillary view: Taken with the patient prone with the beam directed cephalad to the axilla 25 degrees from the horizontal and 25 degrees medially. It provides a tangential view of the anteroinferior glenoid rim.

• Hill-Sachs view: An AP radiograph is taken with the shoulder in maximal internal rotation to visualize posterolateral defect (Hill-Sachs lesion) caused by an impression fracture on the glenoid rim.

• Stryker notch view: The patient is supine with the ipsilateral palm on the crown of head and the elbow pointing straight upward. The x-ray beam is directed 10 degrees cephalad, aimed at coracoid. One is able to visualize 90% of posterolateral humeral head defects.

• Computed tomography may be useful in defining humeral head or glenoid impression fractures, loose bodies, and anterior labral bony injuries (bony Bankart lesion).

• Single- or double-contrast arthrography may be utilized in cases in which the diagnosis may be unclear; it may demonstrate pseudosubluxation, or traumatic epiphyseal separation of the proximal humerus, in a neonate with an apparent glenohumeral dislocation.

• Magnetic resonance imaging may be used to identify rotator cuff, capsular, and glenoid labral (Bankart lesion) pathology.

• Atraumatic dislocations may demonstrate congenital aplasia or absence of the glenoid on radiographic evaluation.

Classification

 

Degree of stability:	Dislocation versus subluxation
Chronology:	Congenital Acute versus chronic Locked (fixed) Recurrent Acquired: generally from repeated minor injuries (swimming, gymnastics, weights); labrum often intact; capsular laxity; increased glenohumeral joint volume; subluxation common
Force:	Atraumatic: usually owing to congenital laxity; no injury; often asymptomatic; self-reducing
	Traumatic: usually caused by one major injury; the anteroinferior labrum may be detached (Bankart lesion); unidirectional; generally requires assistance for reduction
Patient contribution:	Voluntary versus involuntary
Direction:	Subcoracoid Subglenoid Intrathoracic

 

Treatment

• Closed reduction should be performed after adequate clinical evaluation and administration of analgesics and or sedation. Described techniques include (see the figures in Chapter 14):

• Traction-countertraction: With the patient in the supine position, a sheet is placed in the axilla of the affected shoulder with traction applied to counter axial traction placed on the affected upper extremity. Steady, continuous traction eventually results in fatigue of the shoulder musculature in spasm and allows reduction of the humeral head.

• Stimson technique: The patient is placed prone on the stretcher with the affected upper extremity hanging free. Gentle, manual traction or 5 lb of weight is applied to the wrist, with reduction effected over 15 to 20 minutes.

• Steel maneuver: With the patient supine, the examiner supports the elbow in one hand while supporting the forearm and wrist with the other. The upper extremity is abducted to 90 degrees and is slowly externally rotated. Thumb pressure is applied by the physician to push the humeral head into place, followed by adduction and internal rotation of the shoulder as the extremity is placed across the chest. There is a higher incidence of iatrogenic fracture.

• Following reduction, acute anterior dislocations are treated with sling immobilization. Total time in sling is controversial but may be up to 4 weeks, after which an aggressive program of rehabilitation for rotator cuff strengthening is instituted. Posterior dislocations are treated for 4 weeks in a commercial splint or shoulder spica cast with the shoulder in neutral rotation, followed by physical therapy.

• Recurrent dislocation or associated glenoid rim avulsion fractures (bony Bankart lesion) may necessitate operative management, including reduction and internal fixation of the anterior glenoid margin, repair of a Bankart lesion (anterior labral tear), capsular shift, or capsulorraphy. Postoperatively, the child is placed in sling immobilization for 4 to 6 weeks with gradual increases in range-of-motion and strengthening exercises.

• Atraumatic dislocations rarely require reduction maneuvers as spontaneous reduction is the rule. Only after an aggressive, supervised rehabilitation program for rotator cuff and deltoid strengthening has been completed should surgical intervention be considered. Vigorous rehabilitation may obviate the need for operative intervention in up to 85% of cases.

• Psychiatric evaluation may be necessary in the management of voluntary dislocators.

Complications

• Recurrent dislocation: The incidence is 50% to 90%, with decreasing rates of recurrence with increasing patient age (up to 100% in children less than 10 years old). It may necessitate operative intervention, with >90% success rate in preventing future dislocation.

• Shoulder stiffness: Procedures aimed at tightening static and dynamic constraints (subscapularis tendon-shortening, capsular shift, etc.) may result in “overtightening,” resulting in a loss of range of motion, as well as possible subluxation in the opposing direction with subsequent accelerated glenohumeral arthritis.

• Neurologic injury: Neurapraxic injury may occur to nerves in proximity to the glenohumeral articulation, especially the axillary nerve and less commonly the musculocutaneous nerve. These typically resolve with time; a lack of neurologic recovery by 3 months may warrant surgical exploration.

• Vascular injury: Traction injury to the axillary artery has been reported in conjunction with nerve injury to the brachial plexus.

 

Pediatric Elbow

EPIDEMIOLOGY

• Elbow fractures represent 8% to 9% of all upper extremity fractures in children.

• Of all elbow fractures, 86% occur at the distal humerus; 55% to 75% of these are supracondylar.

• Most occur in patients 5 to 10 years of age, more commonly in boys.

• There is a seasonal distribution for elbow fractures in children, with the most occurring during the summer and the fewest during the winter.

ANATOMY

• The elbow consists of three joints: the ulnohumeral, radiocapitellar, and proximal radioulnar.

• The vascularity to the elbow is a broad anastomotic network that forms the intraosseous and extraosseous blood supplies.

• The capitellum is supplied by a posterior branch of the brachial artery that enters the lateral crista.

• The trochlea is supplied by a medial branch that enters along the nonarticular medial crista and a lateral branch that crosses the physis.

• There is no anastomotic connection between these two vessels.

• The articulating surface of the capitellum and trochlea projects distally and anteriorly at an angle of approximately 30 to 45 degrees. The center of rotation of the articular surface of each condyle lies on the same horizontal axis; thus, malalignment of the relationships of the condyles to each other changes their arcs of rotation, limiting flexion and extension.

• The carrying angle is influenced by the obliquity of the distal humeral physis; this averages 6 degrees in girls and 5 degrees in boys and is important in the assessment of angular growth disturbances.

• In addition to anterior distal humeral angulation, there is horizontal rotation of the humeral condyles in relation to the diaphysis, with the lateral condyle rotated 5 degrees medially. This medial rotation is often significantly increased with displaced supracondylar fractures.

• The elbow accounts for only 20% of the longitudinal growth of the upper extremity.

• Ossification: With the exception of the capitellum, ossification centers appear approximately 2 years earlier in girls compared with boys

• CRMTOL: The following is a mnemonic for the appearance of the ossification centers around the elbow (Fig. 10):

Capitellum:	6 months to 2 years; includes the lateral crista of the trochlea
Radial head:	4 years
Medial epicondyle:	6 to 7 years

 

Trochlea:	8 years
Olecranon:	8 to 10 years; often multiple centers, which ultimately fuse
Lateral epicondyle:	12 years

 

Figure 10. Ossification and fusion of the secondary centers of the distal humerus. (A) The average ages of the onset of ossification of the various ossification centers are shown for both boys and girls. (B) The ages at which these centers fuse with each other are shown for both boys and girls. (C) The contribution of each secondary center to the overall architecture of the distal humerus is represented by the stippled areas. (From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:662.)

 

MECHANISM OF INJURY

• Indirect: This is most commonly a result of a fall onto an outstretched upper extremity.

• Direct: Direct trauma to the elbow may occur from a fall onto a flexed elbow or from an object striking the elbow (e.g., baseball bat, automobile).

CLINICAL EVALUATION

• Patients typically present with varying degrees of gross deformity, usually accompanied by pain, swelling, tenderness, irritability, and refusal to use the injured extremity.

• The ipsilateral shoulder, humeral shaft, forearm, wrist, and hand should be examined for associated injuries.

• A careful neurovascular examination should be performed, with documentation of the integrity of the median, radial, and ulnar nerves, as well as distal pulses and capillary refill. Massive swelling in the antecubital fossa should alert the examiner to evaluate for compartment syndrome of the forearm. Flexion of the elbow in the presence of antecubital swelling may cause neurovascular embarrassment; repeat evaluation of neurovascular integrity is essential following any manipulation or treatment.

• All aspects of the elbow should be examined for possible open lesions; clinical suspicion may be followed with intraarticular injection of saline into the elbow to evaluate possible intraarticular communication of a laceration.

RADIOGRAPHIC EVALUATION

• Standard anteroposterior (AP) and lateral views of the elbow should be obtained. On the AP view, the following angular relationships may be determined (Fig. 11):

• Baumann angle: This is the angulation of the lateral condylar physeal line with respect to the long axis of the humerus; normal is 15 to 20 degrees and equal to the opposite side.

• Humeral-ulnar angle: This angle is subtended by the intersection of the diaphyseal bisectors of the humerus and ulna; this best reflects the true carrying angle.

• Metaphyseal-diaphyseal angle: This angle is formed by a bisector of the humeral shaft with respect to a line delineated by the widest points of the distal humeral metaphysic.

Figure 11. Anteroposterior x-ray angles for the elbow. (A) The Baumann angle (О±). (B) The humeral-ulnar angle. (C) The metaphyseal-diaphyseal angle. (From O’Brien WR, Eilert RE, Chang FM, et al. The metaphyseal-diaphyseal angle as a guide to treating supracondylar fractures of the humerus in children, 1999, unpublished data.)

 

Internal and external rotation views may be obtained in cases in which a fracture is suspected but not clearly demonstrated on routine views. These may be particularly useful in the identification of coronoid process or radial head fractures.

• On a true lateral radiograph of the elbow flexed to 90 degrees, the following landmarks should be observed (Fig. 12):

• Teardrop: This radiographic shadow is formed by the posterior margin of the coronoid fossa anteriorly, the anterior margin of the olecranon fossa posteriorly, and the superior margin of the capitellar ossification center inferiorly.

• Diaphyseal-condylar angle: This projects 30 to 45 degrees anteriorly; the posterior capitellar physis is typically wider than the anterior physis.

• Anterior humeral line: When extended distally, this line should intersect the middle third of the capitellar ossification center.

• Coronoid line: A proximally directed line along the anterior border of the coronoid process should be tangent to the anterior aspect of the lateral condyle.

Figure 12. Intraosseous blood supply of the distal humerus. (A) The vessels supplying the lateral condylar epiphysis enter on the posterior aspect and course for a considerable distance before reaching the ossific nucleus. (B) Two definite vessels supply the ossification center of the medial crista of the trochlea. The lateral one enters by crossing the physis. The medial one enters by way of the nonarticular edge of the medial crista. (From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:663.)

• Special views

• Jones view: Pain may limit an AP radiograph of the elbow in extension; in these cases, a radiograph may be taken with the elbow hyperflexed and the beam directed at the elbow through the overlying forearm with the arm flat on the cassette ieutral rotation.

• The contralateral elbow should be obtained for comparison as well as identification of ossification centers. A pseudofracture of an ossification center may exist, in which apparent fragmentation of an ossification center may represent a developmental variant rather than a true fracture. This may be clarified with comparison views of the uninjured contralateral elbow.

 

• Fat pad signs: Three fat pads overlie the major structures of the elbow (Fig. 13):

 

Figure 13. Elevated anterior and posterior fat pads. (Adapted from The Journal of Bone and Joint Surgery, in Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Anterior (coronoid) fat pad: This triangular lucency seen anterior to the distal humerus may represent displacement of the fat pad owing to underlying joint effusion. The coronoid fossa is shallow; therefore, anterior displacement of the fat pad is sensitive to small effusions. However, an exuberant fat pad may be seen without associated trauma, diminishing the specificity of the anterior fat pad sign.

• Posterior (olecranon) fat pad: The deep olecranon fossa normally completely contains the posterior fat pad. Thus, only moderate to large effusions cause posterior displacement, resulting in a high specificity of the posterior fat pad sign for intraarticular disorders (a fracture is present >70% of the time when the posterior fat pad is seen).

• Supinator fat pad: This represents a layer of fat on the anterior aspect of the supinator muscle as it wraps around the proximal radius. Anterior displacement of this fat pad may represent a fracture of the radial neck; however, this sign has been reported to be positive in only 50% of cases.

• Anterior and posterior fat pads may not be seen following elbow dislocation owing to disruption of the joint capsule, which decompresses the joint effusion.

 

SPECIFIC FRACTURES

Supracondylar Humerus Fractures

Epidemiology

• These comprise 55% to 75% of all elbow fractures.

• The male-to-female ratio is 3:2.

• The peak incidence is from 5 to 8 years, after which dislocations become more frequent.

• The left, or nondominant side, is most frequently injured.

Anatomy

• Remodeling of bone in the 5- to 8-year old causes a decreased anteroposterior diameter in the supracondylar region, making this area susceptible to injury.

• Ligamentous laxity in this age range increases the likelihood of hyperextension injury.

• The anterior capsule is thickened and stronger than the posterior capsule. In extension, the fibers of the anterior capsule are taut, serving as a fulcrum by which the olecranon becomes firmly engaged in the olecranon fossa. With extreme force, hyperextension may cause the olecranon process to impinge on the superior olecranon fossa and supracondylar region.

• The periosteal hinge remains intact on the side of the displacement.

Mechanism of Injury

• Extension type: Hyperextension occurs during fall onto an outstretched hand with or without varus/valgus force. If the hand is pronated, posteromedial displacement occurs. If the hand is supinated posterolateral displacement occurs. Posteromedial displacement is more common.

• Flexion type: The cause is direct trauma or a fall onto a flexed elbow.

Clinical Evaluation

• Patients typically present with a swollen, tender elbow with painful range of motion.

• S-shaped angulation at the elbow: a complete (Type III) fracture results in two points of angulation to give it an S shape.

• Pucker sign: This is dimpling of the skin anteriorly secondary to penetration of the proximal fragment into the brachialis muscle; it should alert the examiner that reduction of the fracture may be difficult with simple manipulation.

• Neurovascular examination: A careful neurovascular examination should be performed with documentation of the integrity of the median, radial, and ulnar nerves as well as their terminal branches. Capillary refill and distal pulses should be documented. The examination should be repeated following splinting or manipulation.

Classification

 

EXTENSION TYPE

This represents 98% of supracondylar humerus fractures in children.

Gartland

This is based on the degree of displacement.

Type I:	Nondisplaced
Type II:	Displaced with intact posterior cortex; may be angulated or rotated
Type III:	Complete displacement; posteromedial or posterolateral

 

FLEXION TYPE

This comprises 2% of supracondylar humerus fractures in children.

Gartland

Type I:	Nondisplaced
Type II:	Displaced with intact anterior cortex
Type III:	Complete displacement; usually anterolateral

 

Treatment

 

EXTENSION TYPE

Type I:	Immobilization in a long arm cast or splint at 60 to 90 degrees of flexion is indicated for 2 to 3 weeks.
Type II:	This is usually reducible by closed methods followed by casting; it may require pinning if unstable (crossed pins versus two lateral pins) or if reduction cannot be maintained without excessive flexion that may place neurovascular structures at risk.
Type III:	Attempt closed reduction and pinning; traction (olecranon skeletal traction) may be needed for comminuted fractures with marked soft tissue swelling or damage. Open reduction and internal fixation may be necessary for rotationally unstable fractures, open fractures, and those with neurovascular injury (crossed pins versus two lateral pins).

• Concepts involved in reduction
• Displacement is corrected in the coronal and horizontal planes before the sagittal plane.

• Hyperextension of the elbow with longitudinal traction is used to obtain apposition.

• Flexion of the elbow is done while applying a posterior force to the distal fragment.

• Stabilization with control of displacement in the coronal, sagittal, and horizontal planes is recommended.

• Lateral pins are placed first to obtain provisional stabilization, and if a medial pin is needed, the elbow can be extended before pin placement to help protect the ulnar nerve.

FLEXION TYPE

Type I:	Immobilization in a long arm cast iear extension is indicated for 2 to 3 weeks.
Type II:	Closed reduction is followed by percutaneous pinning with two lateral pins or crossed pins.
Type III:	Reduction is often difficult; most require open reduction and internal fixation with crossed pins.

• Immobilization in a long arm cast (or posterior splint if swelling is an issue) with the elbow flexed to 90 degrees and the forearm ieutral should be undertaken for 2 to 3 weeks postoperatively, at which time the cast may be discontinued and the pins removed. The patient should then be maintained in a sling with range-of-motion exercises and restricted activity for an additional 4 to 6 weeks.

Complications

• Neurologic injury (7% to 10%): This may be caused by a traction injury during reduction owing to tenting or entrapment at the fracture site. It also may occur as a result of Volkmann ischemic contracture, angular deformity, or incorporation into the callus or scar. Most are neurapraxias requiring no treatment.
• Mediaerve/anterior interosseous nerve (most common)

• Radial nerve
• Ulnar nerve: This is most common in flexion-type supracondylar fractures; early injury may result from tenting over the medial spike of the proximal fragment; late injury may represent progressive valgus deformity of the elbow. It is frequently iatrogenic in extension-type supracondylar fractures following medial pinning.

• Vascular injury (0.5%): This may represent direct injury to the brachial artery or may be secondary to antecubital swelling. This emphasizes the need for a careful neurovascular examination both on initial presentation and following manipulation or splinting, especially after elbow flexion is performed. Observation may be warranted if the pulse is absent, yet the hand is still well perfused.

• Loss of motion: A >5-degree loss of elbow motion occurs in 5% secondary to poor reduction or soft tissue contracture.

• Myositis ossificans: Rare and is seen after vigorous manipulation.

• Angular deformity (varus more frequently than valgus): Significant in 10% to 20%; the occurrence is decreased with percutaneous pinning (3%) compared with reduction and casting alone (14%).

• Compartment syndrome (<1%): This rare complication can be exacerbated by elbow hyperflexion when excessive swelling is present in the cubital fossa.

Lateral Condylar Physeal Fractures

Epidemiology

• These comprise 17% of all distal humerus fractures.

• Peak age is 6 years.
• Often result in less satisfactory outcomes than supracondylar fractures because:

• Diagnosis less obvious and may be missed in subtle cases.

• Loss of motion is more severe due to intraarticular nature.

• The incidence of growth disturbance is higher.

Anatomy

• The ossification center of the lateral condyle extends to the lateral crista of the trochlea.

• Lateral condylar physeal fractures are typically accompanied by a soft tissue disruption between the origins of the extensor carpi radialis longus and the brachioradialis muscles; these origins remain attached to the free distal fragment, accounting for initial and late displacement of the fracture.

• Disruption of the lateral crista of the trochlea (Milch Type II fractures) results in posterolateral subluxation of the proximal radius and ulna with consequent cubitus valgus; severe posterolateral translocation may lead to the erroneous diagnosis of primary elbow dislocation.

Mechanism of Injury

• “Pull-off” theory: Avulsion injury occurs by the common extensor origin owing to a varus stress exerted on the extended elbow.

• “Push-off” theory: A fall onto an extended upper extremity results in axial load transmitted through the forearm, causing the radial head to impinge on the lateral condyle.

Clinical Evaluation

• Unlike the patient with a supracondylar fracture of the elbow, patients with lateral condylar fractures typically present with little gross distortion of the elbow, other than mild swelling from fracture hematoma most prominent over the lateral aspect of the distal humerus.

• Crepitus may be elicited associated with supination-pronation motions of the elbow.

• Pain, swelling, tenderness to palpation, painful range of motion, and pain on resisted wrist extension may be observed.

Radiographic Evaluation

• AP, lateral, and oblique views of the elbow should be obtained.

• Varus stress views may accentuate displacement of the fracture.

• In a young child whose lateral condyle is not ossified, it may be difficult to distinguish between a lateral condylar physeal fracture and a complete distal humeral physeal fracture. In such cases, an arthrogram may be helpful, and the relationship of the lateral condyle to the proximal radius is critical:

• Lateral condyle physeal fracture: This disrupts the normal relationship with displacement of the proximal radius laterally owing to loss of stability provided by the lateral crista of the distal humerus.

• Fracture of the entire distal humeral physis: The relationship of the lateral condyle to the proximal radius is intact, often accompanied by posteromedial displacement of the proximal radius and ulna.

• Magnetic resonance imaging (MRI) may help to appreciate the direction of the fracture line and the pattern of fracture.

Classification

 

MILCH (FIG. 14)

Type I:	The fracture line courses lateral to the trochlea and into the capitulotrochlear groove. It represents a Salter-Harris Type IV fracture: the elbow is stable because the trochlea is intact; this is less common.
Type II:	The fracture line extends into the apex of the trochlea. It represents a Salter-Harris Type II fracture: the elbow is unstable because the trochlea is disrupted; this is more common (Fig. 14).

 

 

Figure 14. Physeal fractures of the lateral condyle. (A) Salter-Harris Type IV physeal injury (Milch Type I). (B) Salter-Harris Type II physeal injury (Milch Type II).

(From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:753.)

 

JAKOB

Stage I:	Fracture nondisplaced with an intact articular surface
Stage II:	Fracture with moderate displacement
Stage III:	Complete displacement and rotation with elbow instability

 

Treatment

NONOPERATIVE

• Nondisplaced or minimally displaced fractures (Jakob stage I; <2 mm) (40% of fractures) may be treated with simple immobilization in a posterior splint or long arm cast with the forearm ieutral position and the elbow flexed to 90 degrees. This is maintained for 3 to 4 weeks, after which range-of-motion exercises are instituted.

• Closed reduction of fractures (Jakob stage II) may be performed with the elbow extended and the forearm supinated. Further room for manipulation may be provided by exerting varus stress on the elbow. If the reduction is unable to be held, percutaneous pins may be placed. Closed reduction is unsuccessful in 50% owing to rotation. Late displacement is a frequent complication.

OPERATIVE

• Open reduction is required for unstable Jakobs stage II and stage III fractures (60%).

• The fragment may be secured with two crossed, smooth Kirschner wires that diverge in the metaphysis.

• The passage of smooth pins through the physis does not typically result in growth disturbance.

• Care must be taken when dissecting near the posterior aspect of the lateral condylar fragment because the sole vascular supply is provided through soft tissues in this region.

• Postoperatively, the elbow is maintained in a long arm cast at 60 to 90 degrees of flexion with the forearm ieutral rotation. The cast is discontinued 3 to 4 weeks postoperatively with pin removal. Active range-of-motion exercises are instituted.

• If treatment is delayed (>3 weeks), closed treatment should be strongly considered, regardless of displacement, owing to the high incidence of osteonecrosis of the condylar fragment with late open reduction.

Complications

• Lateral condylar overgrowth with spur formation: This usually results from an ossified periosteal flap raised from the distal fragment at the time of injury or surgery. It may represent a cosmetic problem (cubitus pseudovarus) as the elbow gains the appearance of varus owing to a lateral prominence but is generally not a functional problem.

• Delayed union or nonunion (>12 weeks): This is caused by pull of extensors and poor metaphyseal circulation of the lateral condylar fragment, most commonly in patients treated nonoperatively. It may result in cubitus valgus necessitating ulnar nerve transposition for tardy ulnar nerve palsy. Treatment ranges from benign neglect to osteotomy and compressive fixation late or at skeletal maturity.

• Angular deformity: Cubitus valgus occurs more frequently than varus owing to lateral physeal arrest. Tardy ulnar nerve palsy may develop necessitating transposition.
• Neurologic compromise: This is rare in the acute setting. Tardy ulnar nerve palsy may develop as a result of cubitus valgus.

• Osteonecrosis: This is usually iatrogenic, especially when surgical intervention was delayed. It may result in a “fishtail” deformity with a persistent gap between the lateral physeal ossification center and the medial ossification of the trochlea.

Medial Condylar Physeal Fractures

Epidemiology

• Represent <1% of distal humerus fractures.

• Typical age range is 8 to 14 years.

Anatomy

• Medial condylar fractures are Salter-Harris Type IV fractures with an intraarticular component involving the trochlea and an extraarticular component involving the medial metaphysis and the medial epicondyle (common flexor origin).

• Only the medial crista is ossified by the secondary ossification centers of the medial condylar epiphysis.

• The vascular supply to the medial epicondyle and metaphysis is derived from the flexor muscle group. The vascular supply to the lateral aspect of the medial crista of the trochlea traverses the surface of the medial condylar physis, rendering it vulnerable in medial physeal disruptions with possible avascular complications and “fishtail” deformity.

Mechanism of Injury

• Direct: Trauma to the point of the elbow, such as a fall onto a flexed elbow, results in the semilunar notch of the olecranon traumatically impinging on the trochlea, splitting it with the fracture line extending proximally to metaphyseal region.

• Indirect: A fall onto an outstretched hand with valgus strain on the elbow results in an avulsion injury with the fracture line starting in the metaphysis and propagating distally through the articular surface.

• These are considered the mirror image of lateral condylar physeal fractures.

• Once dissociated from the elbow, the powerful forearm flexor muscles produce sagittal anterior rotation of the fragment.

Clinical Evaluation

• Patients typically present with pain, swelling, and tenderness to palpation over the medial aspect of the distal humerus. Range of motion is painful, especially with resisted flexion of the wrist.

• A careful neurovascular examination is important, because ulnar nerve symptoms may be present.

• A common mistake is to diagnose a medial condylar physeal fracture erroneously as an isolated medial epicondylar fracture. This occurs based on tenderness and swelling medially in conjunction with radiographs demonstrating a medial epicondylar fracture only resulting from the absence of a medial condylar ossification center in younger patients.

• Medial epicondylar fractures are often associated with elbow dislocations, usually posterolateral; elbow dislocations are extremely rare before ossification of the medial condylar epiphysis begins. With medial condylar physeal fractures, subluxation of the elbow posteromedially is often observed. A positive fat pad sign indicates an intraarticular fracture, whereas a medial epicondyle fracture is typically extraarticular with no fat pad sign seen on radiographs.

Radiographic Evaluation

• AP, lateral, and oblique views of the elbow should be obtained.

• In young children whose medial condylar ossification center is not yet present, radiographs may demonstrate a fracture in the epicondylar region; in such cases, an arthrogram may delineate the course of the fracture through the articular surface, indicating a medial condylar physeal fracture.

• Stress views may help to distinguish epicondylar fractures (valgus laxity) from condylar fractures (both varus and valgus laxity).

• MRI may help to appreciate the direction of the fracture line and the pattern of fracture.

Classification

MILCH (FIG. 15)

Type I:	Fracture line traversing through the apex of the trochlea: Salter-Harris Type II; more common presentation
Type II:	Fracture line through capitulotrochlear groove: Salter-Harris Type IV; infrequent presentation

KILFOYLE

Stage I:	Nondisplaced, articular surface intact
Stage II:	Fracture line complete with minimal displacement
Stage III:	Complete displacement with rotation of fragment from pull of flexor mass

Figure 15. Fracture patterns. Left: In the Milch Type I injury, the fracture line terminates in the trochlea notch (arrow). Right: In the Milch Type II injury, the fracture line terminates in the capitulotrochlear groove (arrow). (From Rockwood CA, Wilkins KE, Beaty JH. Fractures and Dislocations in Children. Philadelphia: Lippincott-Raven, 1999:786.)

 

Treatment

 

NONOPERATIVE

• Nondisplaced or minimally displaced fractures (Kilfoyle stage I) may be treated with immobilization in a long arm cast or posterior splint with the forearm ieutral rotation and the elbow flexed to 90 degrees for 3 to 4 weeks, followed by range-of-motion and strengthening exercises.

• Closed reduction may be performed with the elbow extended and the forearm pronated to relieve tension on the flexor origin, with placement of a posterior splint or long arm cast. Unstable reductions may require percutaneous pinning with two parallel metaphyseal pins.

• Closed reduction is often difficult because of medial soft tissue swelling, and open reduction is usually required for stage II and III fractures.

OPERATIVE

• Unreducible or unstable Kilfoyle stage II or stage III fractures of the medial condylar physis may require open reduction and internal fixation. Rotation of the condylar fragment may preclude successful closed treatment.

• A medial approach may be used with identification and protection of the ulnar nerve.

• The posterior surface of the condylar fragment and the medial aspect of the medial crista of the trochlea should be avoided in the dissection because these provide the vascular supply to the trochlea.

• Smooth Kirschner wires placed in a parallel configuration extending to the metaphysis may be used for fixation, or cancellous screw fixation may be used in adolescents near skeletal maturity.

• Postoperative immobilization consists of long arm casting with the forearm ieutral rotation and the elbow flexed to 90 degrees for 3 to 4 weeks, at which time the pins and the cast may be discontinued and active range-of-motion exercises instituted.

• If treatment is delayed (>3 weeks), closed treatment should be strongly considered, regardless of displacement, owing to the high incidence of osteonecrosis of the trochlea and lateral condylar fragment from extensive dissection with late open reduction.

Complications

• Missed diagnosis: The most common is a medial epicondylar fracture owing to the absence of ossification of the medial condylar ossification center. Late diagnosis of medial condylar physeal fracture should be treated nonoperatively.

• Nonunion: Uncommon and usually represent untreated, displaced medial condylar physeal fractures secondary to pull of flexors with rotation. They tend to demonstrate varus deformity. After ossification, the lateral edge of the fragment may be observed to extend to the capitulotrochlear groove.

• Angular deformity: Untreated or treated medial condylar physeal fractures may demonstrate angular deformity, usually varus, either secondary to angular displacement or from medial physeal arrest. Cubitus valgus may result from overgrowth of the medial condyle.

• Osteonecrosis: This may result after open reduction and internal fixation, especially when extensive dissection is undertaken.

• Ulnar neuropathy: This may be early, related to trauma, or more commonly, late, related to the development of angular deformities or scarring. Recalcitrant symptoms may be addressed with ulnar nerve transposition.

Transphyseal Fractures

Epidemiology

• Most occur in patients younger than age 6 to 7 years.

• These were originally thought to be extremely rare injuries. It now appears that with advanced imaging (e.g., MRI), they occur fairly frequently, although the exact incidence is not known owing to misdiagnoses.

Anatomy

• The epiphysis includes the medial epicondyle until age 6 to 7 years in girls and 8 to 9 years in boys, at which time ossification occurs. Fractures before this time thus include medial epicondyle.
• The younger the child, the greater the volume of the distal humerus that is occupied by the distal epiphysis; as the child matures, the physeal line progresses distally, with a V-shaped cleft forming between the medial and lateral condylar physes—this cleft protects the distal humeral epiphysis from fracture in the mature child, because fracture lines tend to exit through the cleft.

• The joint surface is not involved in this injury, and the relationship between the radius and capitellum is maintained.

• The anteroposterior diameter of the bone in this region is wider than in the supracondylar region, and consequently there is not as much tilting or rotation.

• The vascular supply to the medial crista of the trochlea courses directly through the physis; in cases of fracture, this may lead to avascular changes.

• The physeal line is in a more proximal location in younger patients, therefore, hyperextension injuries to the elbow tend to result in physeal separations instead of supracondylar fractures through bone.

Mechanism of Injury

• Birth injuries: Rotatory forces coupled with hyperextension injury to the elbow during delivery may result in traumatic distal humeral physeal separation.

• Child abuse: Bright demonstrated that the physis fails most often in shear rather than pure bending or tension. Therefore, in young infants or children, child abuse must be suspected, because a high incidence of transphyseal fracture is associated with abuse.

• Trauma: This may result from hyperextension injuries with posterior displacement, coupled with a rotation moment.

Clinical Evaluation

• Young infants or newborns may present with pseudoparalysis of the affected extremity, minimal swelling, and “muffled crepitus,” because the fracture involves softer cartilage rather than firm, osseous tissue.

• Older children may present with pronounced swelling, refusal to use the affected extremity, and pain that precludes a useful clinical examination or palpation of bony landmarks. In general, because of the large, wide fracture surface there is less tendency for tilting or rotation of the distal fragment, resulting in less deformity than seen in supracondylar fractures. The bony relationship between the humeral epicondyles and the olecranon is maintained.

• A careful neurovascular examination should be performed, because swelling in the cubital fossa may result ieurovascular compromise.

Radiographic Evaluation

• AP, lateral, oblique radiographs should be obtained.

• The proximal radius and ulna maintain normal, anatomic relationships to each other, but they are displaced posteromedially with respect to the distal humerus. This is considered diagnostic of transphyseal fracture.
• Comparison views of the contralateral elbow may be used to identify posteromedial displacement.

• In the child whose lateral condylar epiphysis is ossified, the diagnosis is much more obvious. There is maintenance of the lateral condylar epiphysis to radial head relationship and posteromedial displacement of the distal humeral epiphysis with respect to the humeral shaft.

• Transphyseal fractures with large metaphyseal components may be mistaken for a low supracondylar fracture or a fracture of the lateral condylar physis. These may be differentiated by the presence of a smooth outline of the distal metaphysis in fractures involving the entire distal physis as compared with the irregular border of the distal aspect of the distal fragment seen in supracondylar fractures.

• Elbow dislocations in children are rare, but they may be differentiated from transphyseal fractures by primarily posterolateral displacement and a disrupted relationship between the lateral condylar epiphysis and the proximal radius.

• An arthrogram may be useful for clarification of the fracture pattern and differentiation from an intraarticular fracture.

• MRI may be helpful in appreciating the direction of the fracture line and the pattern of fracture.

• Ultrasound may be useful in evaluating neonates and infants in whom ossification has not yet begun.

Classification

DELEE

This is based on ossification of the lateral condyle.

Group A:	Infant, before the appearance of the lateral condylar ossification center (birth to 7 months); diagnosis easily missed; Salter-Harris type I
Group B:	Lateral condyle ossified (7 months to 3 years); Salter-Harris type I or II (fleck of metaphysis)
Group C:	Large metaphyseal fragment, usually exiting laterally (age 3 to 7 years)

 

Treatment

Because many of these injuries in infants and toddlers represent child abuse injuries, it is not uncommon for parents to delay seeking treatment.

 

NONOPERATIVE

• Closed reduction with immobilization is performed with the forearm pronated and the elbow in 90 degrees of flexion if the injury is recognized early (within 4 to 5 days). This is maintained for 3 weeks, at which time the patient is allowed to resume active range of motion.

• Severe swelling of the elbow may necessitate Dunlop-type sidearm traction. Skeletal traction is typically not necessary.

• When treatment is delayed beyond 6 to 7 days of injury, the fracture should not be manipulated regardless of displacement, because the epiphyseal fragment is no longer mobile and other injuries may be precipitated; rather, splinting for comfort should be undertaken. Most fractures eventually completely remodel by maturity.

OPERATIVE

• DeLee Type C fracture patterns or unstable injuries may necessitate percutaneous pinning for fixation. An arthrogram is usually performed to determine the adequacy of reduction.

• Angulation and rotational deformities that cannot be reduced by closed methods may require open reduction and internal fixation with pinning for fixation.

• Postoperatively, the patient may be immobilized with the forearm in pronation and the elbow flexed to 90 degrees. The pins and cast are discontinued at 3 weeks, at which time active range of motion is permitted.

Complications

• Malunion: Cubitus varus is most common, although the incidence is lower than with supracondylar fractures of the humerus because of the wider fracture surface of transphyseal fractures that do not allow as much angulation compared with supracondylar fractures.

• Neurovascular injury: Extremely rare because the fracture surfaces are covered with cartilage. Closed reduction and immobilization should be followed by repeat neurovascular assessment, given that swelling in the antecubital fossa may result ieurovascular compromise.

• Nonunion: Extremely rare because the vascular supply to this region is good.

• Osteonecrosis: May be related to severe displacement of the distal fragment or iatrogenic injury, especially with late exploration.

Medial Epicondylar Apophyseal Fractures

Epidemiology

• Comprise 14% of distal humerus fractures.

• 50% are associated with elbow dislocations.

• The peak age is 11 to 12 years.

• The male-to-female ratio is 4:1.

Anatomy

• The medial epicondyle is a traction apophysis for the medial collateral ligament and wrist flexors. It does not contribute to humeral length. The forces across this physis are tensile rather than compressive.

• Ossification begins at 4 to 6 years of age; it is the last ossification center to fuse with the metaphysis (15 years) and does so independently of the other ossification centers.

• The fragment is usually displaced distally and may be incarcerated in the joint 15% to 18% of the time.

• It is often associated with fractures of the proximal radius, olecranon and coronoid.

• In younger children, a medial epicondylar apophyseal fracture may have an intracapsular component, because the elbow capsule may attach as proximally as the physeal line of the epicondyle. In the older child, these fractures are generally extracapsular given that the capsular attachment is more distal, to the medial crista of the trochlea.

Mechanism of Injury

• Direct: Trauma to the posterior or posteromedial aspect of the medial epicondyle may result in fracture, although these are rare and tend to produce fragmentation of the medial epicondylar fragment.

• Indirect:

• Secondary to elbow dislocation: The ulnar collateral ligament provides avulsion force.

• Avulsion injury by flexor muscles results from valgus and extension force during a fall onto an outstretched hand or secondary to an isolated muscle avulsion from throwing a ball or arm wrestling, for example.

• Chronic: Related to overuse injuries from repetitive throwing, as seen in skeletally immature baseball pitchers.

Clinical Evaluation

• Patients typically present with pain, tenderness, and swelling medially.

• Symptoms may be exacerbated by resisted wrist flexion.

• A careful neurovascular examination is essential, because the injury occurs in proximity to the ulnar nerve, which can be injured during the index trauma or from swelling about the elbow.

• Decreased range of motion is usually elicited and may be secondary to pain. Occasionally, a mechanical block to range of motion may result from incarceration of the epicondylar fragment within the elbow joint.

• Valgus instability can be appreciated on stress testing with the elbow flexed to 15 degrees to eliminate the stabilizing effect of the olecranon.

Radiographic Evaluation

• AP, lateral, and oblique radiographs of the elbow should be obtained.

• Because of the posteromedial location of the medial epicondylar apophysis, the ossification center may be difficult to visualize on the AP radiograph if it is even slightly oblique.

• The medial epicondylar apophysis is frequently confused with fracture because of the occasionally fragmented appearance of the ossification center as well as the superimposition on the distal medial metaphysis. Better visualization may be obtained by a slight oblique of the lateral radiograph, which demonstrates the posteromedial location of the apophysis.

• A gravity stress test may be performed, demonstrating medial opening on stress radiographs.

• Complete absence of the apophysis on standard elbow views should prompt a search for the displaced fragment after comparison views of the contralateral, normal elbow are obtained. Specifically, incarceration within the joint must be sought, because the epicondylar fragment may be obscured by the distal humerus.

• Fat pad signs are unreliable, given that epicondylar fractures are extracapsular in older children and capsular rupture associated with elbow dislocation may compromise its ability to confine the hemarthrosis.

• It is important to differentiate this fracture from a medial condylar physeal fracture; MRI or arthrogram may delineate the fracture pattern, especially when the medial condylar ossification center is not yet present.

Classification

• Acute

• Nondisplaced

• Minimally displaced

• Significantly displaced (>5 mm) with a fragment proximal to the joint

• Incarcerated fragment within the olecranon-trochlea articulation

• Fracture through or fragmentation of the epicondylar apophysis, typically from direct trauma

• Chronic

• Tension stress injuries (“Little League elbow”)

Treatment

 

NONOPERATIVE

• Most medial epicondylar fractures may be managed nonoperatively with immobilization. Studies demonstrate that although 60% may establish only fibrous union, 96% have good or excellent functional results.

• Nonoperative treatment is indicated for nondisplaced or minimally displaced fractures and for significantly displaced fractures in older or low-demand patients.

• The patient is initially placed in a posterior splint with the elbow flexed to 90 degrees with the forearm ieutral or pronation.

• The splint is discontinued 3 to 4 days after injury and early active range of motion is instituted. A sling is worn for comfort.

• Aggressive physical therapy is generally not necessary unless the patient is unable to perform active range-of-motion exercises.

OPERATIVE

• An absolute indication for operative intervention is an irreducible, incarcerated fragment within the elbow joint. Closed manipulation may be used to attempt to extract the incarcerated fragment from the joint as described by Roberts. The forearm is supinated, and valgus stress is applied to the elbow, followed by dorsiflexion of the wrist and fingers to put the flexors on stretch. This maneuver is successful approximately 40% of the time.

• Relative indications for surgery include ulnar nerve dysfunction owing to scar or callus formation, valgus instability in an athlete, or significantly displaced fractures in younger or high-demand patients.

• Acute fractures of the medial epicondyle may be approached through a longitudinal incision just anterior to the medial epicondyle. Ulnar nerve identification is important, but extensive dissection or transposition is generally unnecessary. After reduction and provisional fixation with Kirschner wires, fixation may be achieved with a lag-screw technique. A washer may be used in cases of poor bone stock or fragmentation.

• Postoperatively, the patient is placed in a posterior splint or long arm cast with the elbow flexed to 90 degrees and the forearm pronated. This may be converted to a removable posterior splint or sling at 7 to 10 days postoperatively, at which time active range-of-motion exercises are instituted. Formal physical therapy is generally unnecessary if the patient is able to perform active exercises.

Complications

• Unrecognized intraarticular incarceration: An incarcerated fragment tends to adhere and form a fibrous union to the coronoid process, resulting in significant loss of elbow range of motion. Although earlier recommendations were to manage this nonoperatively, recent recommendations are to explore the joint with excision of the fragment.

• Ulnar nerve dysfunction: The incidence is 10% to 16%, although cases associated with fragment incarceration may have up to a 50% incidence of ulnar nerve dysfunction. Tardy ulnar neuritis may develop in cases involving reduction of the elbow or manipulation in which scar tissue may be exuberant. Surgical exploration and release may be warranted for symptomatic relief.

• Nonunion: May occur in up to 60% of cases with significant displacement treated nonoperatively, although it rarely represents a functional problem.

• Loss of extension: A 5% to 10% loss of extension is seen in up to 20% of cases, although this rarely represents a functional problem. This emphasizes the need for early active range-of-motion exercises.

• Myositis ossificans: Rare, related to repeated and vigorous manipulation of the fracture. It may result in functional block to motion and must be differentiated from ectopic calcification of the collateral ligaments related to microtrauma, which does not result in functional limitation.

Lateral Epicondylar Apophyseal Fractures

Epidemiology

• Extremely rare in children.

Anatomy

• The lateral epicondylar ossification center appears at 10 to 11 years of age; however, ossification is not completed until the second decade of life.

• The lateral epicondyle represents the origin of many of the wrist and forearm extensors; therefore, avulsion injuries account for a proportion of the fractures, as well as displacement once the fracture has occurred.

Mechanism of Injury

• Direct trauma to the lateral epicondyle may result in fracture; these may be comminuted.

• Indirect trauma may occur with forced volarflexion of an extended wrist, causing avulsion of the extensor origin, often with significant displacement as the fragment is pulled distally by the extensor musculature.

Clinical Evaluation

• Patients typically present with lateral swelling and painful range of motion of the elbow and wrist, with tenderness to palpation of the lateral epicondyle.

• Loss of extensor strength may be appreciated.

Radiographic Evaluation

• The diagnosis is typically made on the AP radiograph, although a lateral view should be obtained to rule out associated injuries.

• The lateral epicondylar physis represents a linear radiolucency on the lateral aspect of the distal humerus and is commonly mistaken for a fracture. Overlying soft tissue swelling, cortical discontinuity, and clinical examination should assist the examiner in the diagnosis of lateral epicondylar apophyseal injury.

Classification

DESCRIPTIVE

• Avulsion
• Comminution
• Displacement

Treatment

NONOPERATIVE

• With the exception of an incarcerated fragment within the joint, almost all lateral epicondylar apophyseal fractures may be treated with immobilization with the elbow in the flexed, supinated position until comfortable, usually by 2 to 3 weeks.

OPERATIVE

• Incarcerated fragments within the elbow joint may be simply excised. Large fragments with associated tendinous origins may be reattached with screws or Kirschner wire fixation and postoperative immobilization for 2 to 3 weeks until comfortable.

Complications

• Nonunion: Commonly occurs with established fibrous union of the lateral epicondylar fragment, although it rarely represents a functional or symptomatic problem.

• Incarcerated fragments: May result in limited range of motion, most commonly in the radiocapitellar articulation, although free fragments may migrate to the olecranon fossa and limit terminal extension.

Capitellum Fractures

Epidemiology

• Of these fractures, 31% are associated with injuries to the proximal radius.

• Rare in children, representing 1:2,000 fractures about the elbow.

• No verified, isolated fractures of the capitellum have ever been described in children younger than 12 years of age.

Anatomy

• The fracture fragment is composed mainly of pure articular surface from the capitellum and essentially nonossified cartilage from the secondary ossification center of the lateral condyle.

 

Mechanism of Injury

• Indirect force from axial load transmission from the hand through the radial head causes the radial head to strike the capitellum.

• The presence of recurvatum or cubitus valgus predisposes the elbow to this fracture pattern.

Clinical Evaluation

• Patients typically present with minimal swelling with painful range of motion. Flexion is often limited by the fragment.

• Valgus stress tends to reproduce the pain over the lateral aspect of the elbow.

• Supination and pronation may accentuate the pain.

Radiographic Evaluation

• AP and lateral views of the elbow should be obtained.

• Radiographs of the normal, contralateral elbow may be obtained for comparison.

• If the fragment is large and encompasses ossified portions of the capitellum, it is most readily appreciated on the lateral radiograph.

• Oblique views of the elbow may be obtained if radiographic abnormality is not appreciated on standard AP and lateral views, especially because a small fragment may be obscured by the density of the overlying distal metaphysis on the AP view.

• Arthrography or MRI may be helpful when a fracture is not apparent but is suspected to involve purely cartilaginous portions of the capitellum.

Classification

Type I:	Hahn-Steinthal fragment: large osseous component of capitellum, often involving the lateral crista of the trochlea
Type II:	Kocher-Lorenz fragment: articular cartilage with minimal subchondral bone attached; “uncapping of the condyle”

Treatment

NONOPERATIVE

• Nondisplaced or minimally displaced fractures may be treated with casting with the elbow in hyperflexion.

• Immobilization should be maintained until 2 to 4 weeks or evidence of radiographic healing, at which time active exercises should be instituted.

OPERATIVE

• Adequate reduction of displaced fractures is difficult with closed manipulation. Modified closed reduction involving placement of a Steinmann pin into the fracture fragment with manipulation into the reduced position may be undertaken, with postoperative immobilization consisting of casting with the elbow in hyperflexion.

• Excision of the fragment is indicated for fractures in which the fragment is small, comminuted, old (>2 weeks), or not amenable to anatomic reduction without significant dissection of the elbow.

• Open reduction and internal fixation may be achieved by the use of two lag screws, headless screws, or Kirschner wires placed posterior to anterior or anterior to posterior. The heads of the screws must be countersunk to avoid intraarticular impingement.

• Postoperative immobilization should consist of casting with the elbow in hyperflexion for 2 to 4 weeks depending on stability, with serial radiographic evaluation.

Complications

• Osteonecrosis of the capitellar fragment: This is uncommon; synovial fluid can typically sustain the fragment until healing occurs.

• Posttraumatic osteoarthritis: This may occur with secondary incongruity from malunion or particularly after a large fragment is excised.

• Stiffness: Loss of extension is most common, especially with healing of the fragment in a flexed position. This is typically not significant, because it usually represents the terminal few degrees of extension.

T-Condylar Fractures

Epidemiology

• Rare, especially in young children, although this rarity may represent misdiagnosis because purely cartilaginous fractures would not be demonstrated on routine radiographs.

• Peak incidence is in patients 12 to 13 years of age.

Anatomy

• Because of the muscular origin of the flexor and extensor muscles of the forearm, fragment displacement is related not only to the inciting trauma but also to the tendinous attachments. Displacement therefore includes rotational deformities in both the sagittal and coronal planes.

• Fractures in the young child may have a relatively intact distal humeral articular surface despite osseous displacement of the overlying condylar fragments because of the elasticity of the cartilage in the skeletally immature patient.

Mechanism of Injury

• Flexion: Most represent wedge-type fractures as the anterior margin of the semilunar notch is driven into the trochlea by a fall onto the posterior aspect of the elbow in >90 degrees of flexion. The condylar fragments are usually anteriorly displaced with respect to the humeral shaft.

• Extension: In this uncommon mechanism, a fall onto an outstretched upper extremity results in a wedge-type fracture as the coronoid process of the ulna is driven into the trochlea. The condylar fragments are typically posteriorly displaced with respect to the humeral shaft.

Clinical Evaluation

• The diagnosis is most often confused with extension-type supracondylar fractures because the patient typically presents with the elbow extended, with pain, limited range of motion, variable gross deformity, and massive swelling about the elbow.

• The ipsilateral shoulder, humeral shaft, forearm, wrist, and hand should be examined for associated injuries.

• A careful neurovascular examination is essential, with documentation of the integrity of the median, radial, and ulnar nerves, as well as distal pulses and capillary refill. Massive swelling in the antecubital fossa should alert the examiner to evaluate for compartment syndrome of the forearm. Flexion of the elbow in the presence of antecubital swelling may cause neurovascular embarrassment; repeat evaluation of neurovascular integrity is thus essential following any manipulation or treatment.

• All aspects of the elbow should be examined for possible open lesions; clinical suspicion may be followed with intraarticular injection of saline into the elbow to evaluate possible intraarticular communication of a laceration.

Radiographic Evaluation

• Standard AP and lateral views of the injured elbow should be obtained.

• Comparison views of the normal, contralateral elbow may be obtained in which the diagnosis is not readily apparent. Oblique views may aid in further fracture definition.
• In younger patients, the vertical, intercondylar component may involve only cartilaginous elements of the distal humerus; the fracture may thus appear to be purely supracondylar, although differentiation of the two fracture patterns is important because of the potential for articular disruption and incongruency with T-type fractures. An arthrogram should be obtained when intraarticular extension is suspected.

• Computed tomography and MRI are of limited value and are not typically used in the acute diagnosis of T-type fractures. In younger patients, these modalities often require heavy sedation or anesthesia outside of the operating room, in which case an arthrogram is preferred because it allows for evaluation of the articular involvement as well as treatment in the operating room setting.

Classification

Type I:	Nondisplaced or minimally displaced
Type II:	Displaced, with no metaphyseal comminution
Type III:	Displaced, with metaphyseal comminution

Treatment

NONOPERATIVE

• This is reserved only for truly nondisplaced Type I fractures. Thick periosteum may provide sufficient intrinsic stability such that the elbow may be immobilized in flexion with a posterior splint. Mobilization is continued for 1 to 4 weeks after injury.

• Skeletal olecranon traction with the elbow flexed to 90 degrees may be used for patients with extreme swelling, soft tissue compromise, or delayed cases with extensive skin injury that precludes immediate operative intervention. If used as definitive treatment, skeletal traction is usually continued for 2 to 3 weeks, at which time sufficient stability exists for the patient to be converted to a hinged brace for an additional 2 to 3 weeks.

OPERATIVE

• Closed reduction and percutaneous pinning are used with increasing frequency for minimally displaced Type I injuries, in accord with the current philosophy that the articular damage, which cannot be appreciated on standard radiography, may be worse than the apparent osseous involvement.

• Rotational displacement is corrected using a percutaneous joystick in the fracture fragment, with placement of multiple, oblique Kirschner wires for definitive fixation.

• The elbow is then protected in a posterior splint, with removal of pins at 3 to 4 weeks postoperatively.

• Open reduction and internal fixation are undertaken for Type II and Type III fractures using either a posterior, triceps splitting approach, or the triceps-sparing approach as described by Bryan and Morrey. Olecranon osteotomy is generally not necessary for exposure and should be avoided.

• The articular surface is first anatomically reduced and provisionally stabilized with Kirschner wires, followed by metaphyseal reconstruction with definitive fixation using a combination of Kirschner wires, compression screws, and plates.

• Semitubular plates are usually inadequate; pelvic reconstruction plates and specifically designed pediatric J-type plates have been used with success, often with two plates placed 90 degrees offset from one another.

• Postoperatively, the elbow is placed in a flexed position for 5 to 7 days, at which time active range of motion is initiated and a removable cast brace is provided.

Complications

• Loss of range of motion: T-type condylar fractures are invariably associated with residual stiffness, especially to elbow extension, owing to the often significant soft tissue injury as well as articular disruption. This can be minimized by ensuring anatomic reduction of the articular surface, employing arthrographic visualization if necessary, as well as stable internal fixation to decrease soft tissue scarring.

• Neurovascular injury: Rare but is related to significant antecubital soft tissue swelling. Nerve injury to the median, radial, or ulnar nerves may result from the initial fracture displacement or intraoperative traction, although these typically represent neurapraxias that resolve without intervention.

• Growth arrest: Partial or total growth arrest may occur in the distal humeral physis, although it is rarely clinically significant because T-type fractures tend to occur in older children. Similarly, the degree of remodeling is limited, and anatomic reduction should be obtained at the time of initial treatment.

• Osteonecrosis of the trochlea: This may occur especially in association with comminuted fracture patterns in which the vascular supply to the trochlea may be disrupted.

Radial Head and Neck Fractures

Epidemiology

• Of these fractures, 90% involve either physis or neck; the radial head is rarely involved because of the thick cartilage cap.

• Represent 5% to 8.5% of elbow fractures.

• The peak age of incidence is 9 to 10 years.

• Commonly associated fractures include the olecranon, coronoid, and medial epicondyle.

Anatomy

• Ossification of the proximal radial epiphysis begins at 4 to 6 years of age as a small, flat nucleus. It may be spheric or may present as a bipartite structure; these anatomic variants may be appreciated by their smooth, rounded borders without cortical discontinuity.

• Normal angulation of the radial head with respect to the neck ranges between 0 and 15 degrees laterally, and from 10 degrees anterior to 5 degrees posterior angulation.

• Most of the radial neck is extracapsular; therefore, fractures in this region may not result in a significant effusion or a positive fat pad sign.

• No ligaments attach directly to the radial head or neck; the radial collateral ligament attaches to the orbicular ligament, which originates from the radial aspect of the ulna.

Mechanism of Injury

• Acute:
• Indirect: This is most common, usually from a fall onto an outstretched hand with axial load transmission through the proximal radius with trauma against the capitellum.

• Direct: This is uncommon because of the overlying soft tissue mass.

• Chronic:

• Repetitive stress injuries may occur, most commonly from overhead throwing activities. Although most “Little League elbow” injuries represent tension injuries to the medial epicondyle, compressive injuries from valgus stress may result in an osteochondrotic-type disorder of the radial head or an angular deformity of the radial neck.

Clinical Evaluation

• Patients typically present with lateral swelling of the elbow, with pain exacerbated by range of motion, especially supination and pronation.

• Crepitus may be elicited on supination and pronation.

• In a young child, the primary complaint may be wrist pain; pressure over the proximal radius may accentuate the referred wrist pain.

Radiographic Evaluation

• AP and lateral views of the elbow should be obtained. Oblique views may aid in further definition of the fracture line.

• Special views
• Perpendicular views: With an acutely painful, flexed elbow, AP evaluation of the elbow may be obtained by taking one radiograph perpendicular to the humeral shaft, and a second view perpendicular to the proximal radius.

• Radiocapitellar (Greenspan) view: This oblique lateral radiograph is obtained with the beam directed 45 degrees in a proximal direction, resulting in a projection of the radial head anterior to the coronoid process of the anterior ulna (Fig. 16).

Figure 16. Radiocapitellar view. The center of the x-ray beam is directed at 45 degrees to separate the proximal radius and ulna on the x-ray. (From Long BW. Orthopaedic Radiography. Philadelphia: WB Saunders; 1995:152).

• A positive supinator fat pad sign may be present, indicating injury to the proximal radius.

• Comparison views of the contralateral elbow may help identify subtle abnormalities.

• When a fracture is suspected through nonossified regions of the radial head, an arthrogram may be performed to determine displacement.

• MRI may be helpful in appreciating the direction of the fracture line and the pattern of fracture.

 

Classification

 

O’BRIEN

• This is based on the degree of angulation.

Type I:	<30 degrees
Type II:	30 to 60 degrees
Type III:	>60 degrees

 

WILKINS

• This is based on the mechanism of injury.

• Valgus injuries are caused by a fall onto an outstretched hand (compression); angular deformity of the head is usually seen (Fig. 17).

 

Figure 17. Types of valgus injuries. Left: Type A: Salter-Harris type I or II physeal injury. Center: Type B: Salter-Harris type IV injury. Right: Type C: Total metaphyseal fracture pattern. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Type A:	Salter-Harris Type I or II physeal injury
Type B:	Salter-Harris Type III or IV intraarticular injury
Type C:	Fracture line completely within the metaphysis

• Fracture associated with elbow dislocation

• Reduction injury
• Dislocation injury

Treatment

NONOPERATIVE

• Simple immobilization is indicated for O’Brien Type I fractures with <30-degree angulation. This can be accomplished with the use of a collar and cuff, a posterior splint, or a long arm cast for 7 to 10 days with early range of motion.

• Type II fractures with 30- to 60-degree angulation should be managed with manipulative closed reduction.

• This may be accomplished by distal traction with the elbow in extension and the forearm in supination; varus stress is applied to overcome the ulnar deviation of the distal fragment and open up the lateral aspect of the joint, allowing for disengagement of the fragments for manipulation (Patterson) (Fig. 18).

Figure 18. Patterson’s manipulative technique. Left: An assistant grabs the patient’s arm proximally with one hand placed medially against the distal humerus. The surgeon applies distal traction with the forearm supinated and pulls the forearm into varus. Right: Digital pressure applied directly over the tilted radial head completes the reduction. (Adapted from Patterson RF. Treatment of displaced transverse fractures of the neck of the radius in children. J Bone Joint Surg 1934;16:696×2013;698; in Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Israeli described a technique in which the elbow is placed in flexion, and the surgeon’s thumb is used to apply pressure over the radial head while the forearm is forced into a pronated position (Fig. 19).

Figure 19. Flexion-pronation (Israeli) reduction technique. (A) With the elbow in 90 degrees of flexion, the thumb stabilizes the displaced radial head. Usually the distal radius is in a position of supination. The forearm is pronated to swing the shaft up into alignment with the neck (arrow). (B) Movement is continued to full pronation for reduction (arrow). (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Chambers reported another technique for reduction in which an Esmarch wrap is applied distally to proximally, and the radius is reduced by the circumferential pressure.

• Following reduction, the elbow should be immobilized in a long arm cast in pronation with 90 degrees of flexion. This should be maintained for 10 to 14 days, at which time range-of-motion exercises should be initiated.

OPERATIVE

• O’Brien Type II fractures (30- to 60-degree angulation) that are unstable following closed reduction may require the use of percutaneous Kirschner wire fixation. This is best accomplished

• by the use of a Steinmann pin placed in the fracture fragment under image intensification for manipulation, followed by oblique Kirschner wire fixation after reduction is achieved. The patient is then placed in a long arm cast in pronation with 90-degree elbow flexion for 3 weeks, at which time the pins and cast are discontinued and active range of motion is initiated

• Indications for open reduction and internal fixation include fractures that are irreducible by closed means, Type III fractures (>60-degree angulation), fractures with >4 mm translation, and medial displacement fractures (these are notoriously difficult to reduce by closed methods). Open reduction with oblique Kirschner wire fixation is recommended; transcapitellar pins are contraindicated because of a high rate of breakage, as well as articular destruction from even slight postoperative motion.

• The results of open treatment are not significantly different from those of closed treatment; therefore, closed treatment should be performed when possible.

• Radial head excision gives poor results in children owing to the high incidence of cubitus valgus and radial deviation at the wrist due to the continued growth of the child.

Prognosis

• From 15% to 23% will have a poor result regardless of treatment.

• Predictors of a favorable prognosis include:

• <10 years of age.
• Isolated injury.
• Minimal soft tissue injury.
• Good fracture reduction.
• <30-degree initial angulation.
• <3-mm initial displacement.
• Closed treatment.
• Early treatment.

Complications

• Decreased range of motion occurs in (in order of decreasing frequency) pronation, supination, extension, flexion. The reason is loss of joint congruity and fibrous adhesions. Additionally, enlargement of the radial head following fracture may contribute to loss of motion.

• Radial head overgrowth: From 20% to 40% of cases will experience posttraumatic overgrowth of the radial head, owing to increased vascularity from the injury that stimulates epiphyseal growth.

• Premature physeal closure: Rarely results in shortening >5 mm, although it may accentuate cubitus valgus.

• Osteonecrosis of the radial head: Occurs in 10% to 20%, related to amount of displacement; 70% of cases of osteonecrosis are associated with open reduction.

• Neurologic: Usually posterior interosseous nerve neurapraxia; during surgical exposure, pronating the forearm causes the posterior interosseous nerve to move ulnarly, out of the surgical field.

• Radioulnar synostosis: The most serious complication, usually occurring following open reduction with extensive dissection, but it has been reported with closed manipulations and is associated with a delay in treatment of >5 days. It may require exostectomy to improve function.
• Myositis ossificans: May complicate up to 32% of cases, mostly involving the supinator.

Radial Head Subluxation

Epidemiology

• Referred to as “nursemaid’s elbow” or “pulled elbow.”

• Male-to-female ratio is 1:2.

• Occurs in the left elbow 70% of the time.

• Occurs at ages 6 months to 6 years, with a peak at ages 2 to 3 years.

• Recurrence rate is 5% to 30%.

Anatomy

• Primary stability of the proximal radioulnar joint is conferred by the annular ligament, which closely apposes the radial head within the radial notch of the proximal ulna.

• The annular ligament becomes taut in supination of the forearm owing to the shape of the radial head.

• The substance of the annular ligament is reinforced by the radial collateral ligament at the elbow joint.

• After age 5 years, the distal attachment of the annular ligament to the neck of the radius strengthens significantly to prevent tearing or subsequent displacement.

Mechanism of Injury

• Longitudinal traction force on extended elbow is the cause, although it remains controversial whether the lesion is produced in forearm supination or pronation (it is more widely accepted that the forearm must be in pronation for the injury to occur).

Clinical Evaluation

• Patients typically present with an appropriate history of sudden, longitudinal traction applied to the extended upper extremity (such as a child “jerked” back from crossing the street), often with an audible snap. The initial pain subsides rapidly, and the patient allows the upper extremity to hang in the dependent position with the forearm pronated and elbow slightly flexed and refuses to use the ipsilateral hand (pseudoparalysis).

• A history of a longitudinal pull may be absent in 33% to 50% of cases.

• Effusion is rare, although tenderness can usually be elicited over the anterior and lateral aspects of the elbow.

• A neurovascular examination should be performed, although the presence of neurovascular compromise should alert the physician to consider other diagnostic possibilities because neurovascular injury is not associated with simple radial head subluxation.

Radiographic Evaluation

• Radiographs are not necessary if there is a classic history, the child is 5 years old or younger, and the clinical examination is strongly supportive. Otherwise, standard AP and lateral views of the elbow should be obtained.

• Radiographic abnormalities are not typically appreciated, although some authors have suggested that on the AP radiograph >3 mm lateral displacement of the radial head with respect to the capitellum is indicative of radial head subluxation. However, disruption of the radiocapitellar axis is subtle and often obscured by even slight rotation; therefore, even with a high index of suspicion, appreciation of this sign is generally present in only 25% of cases.

• Ultrasound is not routinely used in the evaluation of radial head subluxation, but it may demonstrate an increase in the echonegative area between the radial head and the capitellum (radiocapitellar distance typically about 7.2 mm; a difference of >3 mm between the normal and injured elbow suggests of radial head subluxation).

Classification

• A classification scheme for radial head subluxation does not exist.

• It is important to rule out other diagnostic possibilities, such as early septic arthritis or proximal radius fracture, which may present in a similar fashion, especially if a history of a longitudinal pull is absent.

Treatment

• Closed reduction

• The forearm is supinated with thumb pressure on the radial head.

• The elbow is then brought into maximum flexion with the forearm still in supination.

• Hyperpronation may also be used to reduce the subluxation.

• A palpable “click” may be felt on reduction.

• The child typically experiences a brief moment of pain with the reduction maneuver, followed by the absence of pain and normal use of the upper extremity 5 to 10 minutes later.

• Postreduction films are generally unnecessary. A child who remains irritable may require further workup for other disorders or a repeat attempt at reduction. If the subluxation injury occurred 12 to 24 hours before evaluation, reactive synovitis may be present that may account for elbow tenderness and a reluctance to move the joint.

• Sling immobilization is generally unnecessary if the child is able to use the upper extremity without complaint.

Complications

• Chronically unreduced subluxation: Unrecognized subluxation of the radial head generally reduces spontaneously with relief of painful symptoms. In these cases, the subluxation is realized retrospectively.
• Recurrence: Affects 5% to 39% of cases, but generally ceases after 4 to 5 years when the annular ligament strengthens, especially at its distal attachment to the radius.

• Irreducible subluxation: Rare owing to interposition of the annular ligament. Open reduction may be necessary with transection and repair of the annular ligament to obtain stable reduction.

Elbow Dislocations

Epidemiology

• Represent 3% to 6% of all elbow injuries.

• The peak age is 13 to 14 years, after physes are closed.

• There is a high incidence of associated fractures: medial epicondyle, coronoid, and radial head and neck.

Anatomy

• This is a “modified hinge” joint (ginglymotrochoid) with a high degree of intrinsic stability owing to joint congruity, opposing tension of triceps and flexors, and ligamentous constraints. Of these, the anterior bundle of the medial collateral ligament is the most important.

• Three separate articulations
• Ulnohumeral (hinge)
• Radiohumeral (rotation)
• Proximal radioulnar (rotation)
• Stability
• AP: trochlea/olecranon fossa (extension); coronoid fossa, radiocapitellar joint, biceps/triceps/brachialis (flexion)

• Valgus: Medial collateral ligament complex (anterior bundle the primary stabilizer (flexion and extension)) anterior capsule and radiocapitellar joint (extension)

• Varus: Ulnohumeral articulation, lateral ulnar collateral ligament (static); anconeus muscle (dynamic)

• Range of motion is 0 to 150 degrees of flexion, 85 degrees of supination, and 80 degrees of pronation.

• Functionally, range of motion requires 30 to 130 degrees of flexion, 50 degrees of supination, and 50 degrees of pronation.

• Extension and pronation are the positions of relative instability.

Mechanism of Injury

• Most commonly, the cause is a fall onto an outstretched hand or elbow, resulting in a levering force to unlock the olecranon from the trochlea combined with translation of the articular surfaces to produce the dislocation.

• Posterior dislocation: This is a combination of elbow hyperextension, valgus stress, arm abduction, and forearm supination with resultant soft tissue injuries to the capsule, collateral ligaments (especially medial), and musculature.

• Anterior dislocation: A direct force strikes the posterior aspect of the flexed elbow.

Clinical Evaluation

• Patients typically present guarding the injured upper extremity with variable gross instability and massive swelling.

• A careful neurovascular examination is crucial and should be performed before radiographs or manipulation. At significant risk of injury are the median, ulnar, radial, and anterior interosseous nerves and the brachial artery.

• Serial neurovascular examinations should be performed when massive antecubital swelling exists or the patient is believed to be at risk for compartment syndrome.

• Following manipulation or reduction, repeat neurovascular examinations should be performed to monitor neurovascular status.

• Angiography may be necessary to identify vascular compromise. The radial pulse may be present with brachial artery compromise as a result of collateral circulation.

Radiographic Evaluation

• Standard AP and lateral radiographs of the elbow should be obtained.

• Radiographs should be scrutinized for associated fractures about the elbow, most commonly disruption of the apophysis of the medial epicondyle, or fractures involving the coronoid process and radial neck.

Classification

• Chronologic: Acute, chronic (unreduced), or recurrent.

• Descriptive: Based on the relationship of the proximal radioulnar joint to the distal humerus.

• Posterior

• Posterolateral: >90% dislocations

• Posteromedial

• Anterior: Represents only 1% of pediatric elbow dislocations.

• Divergent: This is rare.

• Medial and lateral dislocations: These are not described in the pediatric population.

• Fracture dislocation: Most associated osseous injuries involve the coronoid process of the olecranon, the radial neck, or the medial epicondylar apophysis of the distal humerus. Rarely, shear fractures of the capitellum or trochlea may occur.

Treatment

POSTERIOR DISLOCATION

Nonoperative

• Acute posterior elbow dislocations should be initially managed with closed reduction using sedation and analgesia. Alternatively, general or regional anesthesia may be used.

• Young children (0 to 8 years old): With the patient prone and the affected forearm hanging off the edge of the table, anteriorly directed pressure is applied to the olecranon tip, effecting reduction.

• Older children (>8 years old): With the patient supine, reduction should be performed with the forearm supinated and the elbow flexed while providing distal traction (Parvin). Reduction with the elbow hyperextended is associated with mediaerve entrapment and increased soft tissue trauma.

• Neurovascular status should be reassessed, followed by evaluation of stable range of motion.

• Postreduction radiographs are essential.

• Postreduction management should consist of a posterior splint at 90 degrees with loose circumferential wraps and elevation. Attention should be paid to antecubital and forearm swelling.

• Early, gentle, active range of motion 5 to 7 days after reduction is associated with better long-term results. Forced, passive range of motion should be avoided because redislocation may occur. Prolonged immobilization is associated with unsatisfactory results and greater flexion contractures.

• A hinged elbow brace through a stable arc of motion may be indicated in cases of instability without associated fractures.

• Full recovery of motion and strength requires 3 to 6 months.

Operative

• Indicated for cases of soft tissue and/or bony entrapment in which closed reduction is not possible.

• A large, displaced coronoid fragment requires open reduction and internal fixation to prevent recurrent instability. Medial epicondylar apophyseal disruptions with entrapped fragments must be addressed.

• Lateral ligamentous reconstruction in cases of recurrent instability and dislocation is usually unnecessary.

• An external fixator for grossly unstable dislocations (with disruption of the medial collateral ligament) may be required as a salvage procedure.

ANTERIOR DISLOCATION

• Acute anterior dislocation of the elbow may be managed initially with closed reduction using sedation and analgesia.

• Initial distal traction is applied to the flexed forearm to relax the forearm musculature, followed by dorsally directed pressure on the volar forearm coupled with anteriorly directed pressure on the distal humerus.

• Triceps function should be assessed following reduction, because stripping of the triceps tendon from its olecranon insertion may occur.

• Associated olecranon fractures usually require open reduction and internal fixation.

DIVERGENT DISLOCATION

• This is a rare injury, with two types:

• Anterior-posterior type (ulna posteriorly, radial head anteriorly): This is more common; reduction is achieved in the same manner as for a posterior dislocation concomitant with posteriorly directed pressure over the anterior radial head prominence.

• Mediolateral (transverse) type (distal humerus wedged between radius laterally and ulna medially): This is extremely rare; reduction is by direct distal traction on extended elbow with pressure on the proximal radius and ulna, converging them.

Complications

• Loss of motion (extension): This is associated with prolonged immobilization with initially unstable injuries. Some authors recommend posterior splint immobilization for 3 to 4 weeks, although recent trends have been to begin early (1 week), supervised range of motion. Patients typically experience a loss of the terminal 10 to 15 degrees of extension, which is usually not functionally significant.

• Neurologic compromise: Neurologic deficits occur in 10% of cases. Most complications occur with entrapment of the mediaerve. Ulnar nerve injuries are most commonly associated with disruptions of the medial epicondylar apophysis. Radial nerve injuries occur rarely.
• Spontaneous recovery is usually expected; a decline ierve function (especially after manipulation) or severe pain ierve distribution is an indication for exploration and decompression.

• Exploration is recommended if no recovery is seen after 3 months following electromyography and serial clinical examinations.

• Vascular injury (rare): The brachial artery is most commonly disrupted during injury.

• Prompt recognition of vascular injury is essential, with closed reduction to reestablish perfusion.

• If, after reduction, perfusion is not reestablished, angiography is indicated to identify the lesion, with arterial reconstruction with reverse saphenous vein graft when indicated.

• Compartment syndrome (Volkmann contracture): May result from massive swelling from soft tissue injury. Postreduction care must include aggressive elevation and avoidance of hyperflexion of the elbow. Serial neurovascular examinations and compartment pressure monitoring may be necessary, with forearm fasciotomy when indicated.

• Instability/redislocation: Rare (<1%) after isolated, traumatic posterior elbow dislocation; the incidence is increased in the presence of associated coronoid process and radial head fracture (combined with elbow dislocation, this completes the terrible triad of the elbow). It may necessitate hinged external fixation, capsuloligamentous reconstruction, internal fixation, or prosthetic replacement of the radial head.

• Heterotopic bone/myositis ossificans: This occurs in 3% of pure dislocations, 18% when associated with fractures, most commonly caused by vigorous attempts at reduction.

• Anteriorly, it forms between the brachialis muscle and the capsule; posteriorly, it may form medially or laterally between the triceps and the capsule.

• The risk is increased with a greater degree of soft tissue trauma or the presence of associated fractures.

• It may result in significant loss of function.

• Forcible manipulation or passive stretching increases soft tissue trauma and should be avoided.

• Indomethacin or local radiation therapy is recommended for prophylaxis postoperatively and in the presence of significant soft tissue injury and/or associated fractures. Radiation therapy is contraindicated in the presence of open physes.

• Osteochondral fractures: Anterior shear fractures of the capitellum or trochlea may occur with anterior dislocations of the elbow. The presence of an unrecognized osteochondral fragment in the joint may be the cause of an unsatisfactory result of what initially appeared to be an uncomplicated elbow dislocation.

• Radioulnar synostosis: The incidence is increased with an associated radial neck fracture.

• Cubitus recurvatum: With significant disruption of the anterior capsule, hyperextension of the elbow may occur late, although this is rarely of any functional or symptomatic significance.

Olecranon Fractures

Epidemiology

• These account for 5% of all elbow fractures.

• The peak age is 5 to 10 years.

• Twenty percent have an associated fracture or dislocation; the proximal radius is the most common.

Anatomy

• The olecranon is metaphyseal and has a relatively thin cortex, which may predispose the area to greenstick-type fractures.

• The periosteum is thick, which may prevent the degree of separation seen in adult olecranon fractures.

• The larger amount of epiphyseal cartilage may also serve as a cushion to lessen the effects of a direct blow.

Mechanism of Injury

• Flexion injuries: With the elbow in a semiflexed postion, the pull of the triceps and brachialis muscles places the posterior cortex in tension; this force alone, or in combination with a direct
  blow, may cause the olecranon to fail. The fracture is typically transverse.

• Extension injuries: With the arm extended, the olecranon becomes locked in the olecranon fossa; if a varus or valgus force is then applied, stress is concentrated in the distal aspect of the olecranon; resultant fractures are typically greenstick fractures that remain extraarticular and may extend proximal to the coronoid process.

• Shear injuries: A direct force is applied to the posterior olecranon, resulting in tension failure of the anterior cortex; the distal fragment is displaced anteriorly by the pull of the brachialis and biceps; this is differentiated from the flexion-type injury by an intact posterior periosteum.

Clinical Evaluation

• Soft tissue swelling is typically present over the olecranon.

• An abrasion or contusion directly over the olecranon may indicate a flexion-type injury.

• The patient may lack active extension, although this is frequently difficult to evaluate in an anxious child with a swollen elbow.

Radiographic Evaluation

• Standard AP and lateral x-rays of the elbow should be obtained.

• Fracture lines associated with a flexion injury are perpendicular to the long axis of the olecranon; these differentiate the fracture from the residual physeal line, which is oblique and directed proximal and anterior.

• The longitudinal fracture lines associated with extension injuries may be difficult to appreciate.

• The radiographs should be scrutinized to detect associated fractures, especially proximal radius fractures.

Classification

• Group A: Flexion injuries

• Group B: Extension injuries

• Valgus pattern

• Varus pattern

• Group C: Shear injuries

Treatment

NONOPERATIVE

• Nondisplaced flexion injuries are treated with splint immobilization in 5 to 10 degrees of flexion for 3 weeks; radiographs should be checked in 5 to 7 days to evaluate for early displacement.

• Extension injuries generally need correction of the varus or valgus deformity; this may be accomplished by locking the olecranon in the olecranon fossa with extension and applying a varus or valgus force to reverse the deformity; overcorrection may help to prevent recurrence of the deformity.

• Shear injuries can be treated with immobilization in a hyperflexed position if the posterior periosteum remains intact, with the posterior periosteum functioning as a tension band; operative intervention should be considered if excessive swelling is present that may result in neurovascular compromise in a hyperflexed position.

OPERATIVE

• Displaced or comminuted fractures may require surgical stabilization.

• Determining whether the posterior periosteum is intact is key to determining the stability of a fracture; if a palpable defect is present, or if the fragments separate with flexion of the elbow, internal fixation may be needed.

• Fixation may be achieved with Kirschner wires and a tension band, tension band alone, cancellous screws alone, or cancellous screws and tension band.

• Removal of hardware is frequently required and should be considered when deciding on a fixation technique (i.e., tension band with wire versus tension band with suture).

• Postoperatively, the elbow is immobilized in a cast at 70 to 80 degrees of flexion for 3 weeks, after which active motion is initiated.

Complications

• Delayed union: Rare (<1%) and is usually asymptomatic, even if it progresses to a nonunion.

• Nerve injury: Rare at the time of injury; ulnar neurapraxia has been reported after development of a pseudarthrosis of the olecranon when inadequate fixation was used.

• Elongation: Elongation of the tip of the olecranon may occur after fracture; the apophysis may elongate to the point that it limits elbow extension.

• Loss of reduction: Associated with fractures treated nonoperatively that subsequently displace; it may result in significant loss of elbow function if it is not identified early in the course of treatment.

 

Pediatric Forearm

EPIDEMIOLOGY

• These injuries are very common: They make up 40% of all pediatric fractures (only 4% are diaphyseal fractures), with a 3:1 male predominance in distal radius fractures.

• Eighty percent occur in children >5 years of age.

• The peak incidence corresponds to the peak velocity of growth when the bone is weakest owing to a dissociation between bone growth and mineralization.

• Fifteen percent have ipsilateral supracondylar fracture.

• One percent have neurologic injury, most commonly mediaerve.

• Of pediatric forearm fractures, 60% occur in the distal metaphyses of the radius or ulna, 20% in the shaft, 14% in the distal physis, and <4% in the proximal third.

ANATOMY

• The radial and ulnar shafts ossify during the eighth week of gestation.

• The distal radial epiphysis appears at age 1 year (often from two centers); the distal ulnar epiphysis appears at age 5 years; the radial head appears at age 5 to 7 years; the olecranon appears at age 9 to 10 years. These all close between the ages of 16 and 18 years.
• The distal physis accounts for 80% of forearm growth.

• With advancing skeletal age, there is a tendency for fractures to occur in an increasingly distal location owing to the distal recession of the transition between the more vulnerable wider metaphysis and the more narrow and stronger diaphysis.

• Osteology
• The radius is a curved bone, cylindric in the proximal third, triangular in the middle third, and flat distally with an apex lateral bow.

• The ulna has a triangular shape throughout, with an apex posterior bow in the proximal third.

• The proximal radioulnar joint is most stable in supination where the broadest part of the radial head contacts the radial notch of the ulna and the interosseous membrane is most taut. The annular ligament is its major soft tissue stabilizer.
• The distal radioulnar joint (DRUJ) is stabilized by the ulnar collateral ligament, the anterior and posterior radioulnar ligaments, and the pronator quadratus muscle. Three percent of distal radius fractures have concomitant DRUJ disruption.

• The triangular fibrocartilage complex (TFCC) has an articular disc joined by volar and dorsal radiocarpal ligaments and by ulnar collateral ligament fibers. It attaches to the distal radius at its ulnar margin, with its apex attached to the base of the ulna styloid, extending distally to the base of the fifth metacarpal.

• The periosteum is very strong and thick in the child. It is generally disrupted on the convex fracture side, whereas an intact hinge remains on the concave side. This is an important consideration when attempting closed reduction.
• Biomechanics
• The posterior distal radioulnar ligament is taut in pronation, whereas the anterior ligament is taut in supination.

• The radius effectively shortens with pronation and lengthens with supination.

• The interosseous space is narrowest in pronation and widest ieutral to 30 degrees of supination. Further supination or pronation relaxes the membrane.
• The average range of pronation/supination is 90/90 degrees (50/50 degrees necessary for activities of daily living).

• Middle third deformity has a greater effect on supination, with the distal third affecting pronation to a greater degree.

• Malreduction of 10 degrees in the middle third limits rotation by 20 to 30 degrees.

• Bayonet apposition (overlapping) does not reduce forearm rotation.

• Deforming muscle forces (Fig. 20)
• Proximal third fractures:
• Biceps and supinator: These function to flex and supinate the proximal fragment.

• Pronator teres and pronator quadratus: These pronate the distal fragment.

• Middle third fractures:
• Supinator, biceps, and pronator teres: The proximal fragment is ieutral.

• Pronator quadratus: Pronates the distal fragment.

 

 

 

Figure 20. Deforming muscle forces in both bone forearm fractures. (From Cruess RL. Importance of soft tissue evaluation in both hand and wrist trauma: statistical evaluation. Orthop Clin North Am 1973;4:969.)

• Distal third fractures:
• Brachioradialis: Dorsiflexes and radially deviates the distal segment.

• Pronator quadratus, wrist flexors and extensors, and thumb abductors: They also cause fracture deformity.

MECHANISM OF INJURY

• Indirect: The mechanism is a fall onto an outstretched hand. Forearm rotation determines the direction of angulation:

• Pronation: flexion injury (dorsal angulation)

• Supination: extension injury (volar angulation)

• Direct: Direct trauma to the radial or ulnar shaft.

CLINICAL EVALUATION

• The patient typically presents with pain, swelling, variable gross deformity, and a refusal to use the injured upper extremity.

• A careful neurovascular examination is essential. Injuries to the wrist may be accompanied by symptoms of carpal tunnel compression.

• The ipsilateral hand, wrist, forearm, and arm should be palpated, with examination of the ipsilateral elbow and shoulder to rule out associated fractures or dislocations.

• In cases of dramatic swelling of the forearm, compartment syndrome should be ruled out on the basis of serial neurovascular examinations with compartment pressure monitoring if indicated. Pain on passive extension of the digits is most sensitive for recognition of a possible developing compartment syndrome; the presence of any of the “classic” signs of compartment syndrome (pain out of proportion to injury, pallor, paresthesias, pulselessness, paralysis) should be aggressively evaluated with possible forearm fasciotomy.

• Examination of skin integrity must be performed, with removal of all bandages and splints placed in the field.

RADIOGRAPHIC EVALUATION

• Anteroposterior and lateral views of forearm, wrist, and elbow should be obtained. The forearm should not be rotated to obtain these views; instead, the beam should be rotated to obtain a cross-table view.

• The bicipital tuberosity is the landmark for identifying the rotational position of the proximal fragment (Fig. 21):

• Ninety degrees of supination: It is directed medially.

• Neutral: It is directed posteriorly.

• Ninety degrees of pronation: This is directed laterally.

• In the normal, uninjured radius, the bicipital tuberosity is 180 degrees to the radial styloid.

Figure 21. The normal bicipital tuberosity from full supination (90 degrees) to midposition (0 degrees). In children, these characteristics are less clearly defined. (From Rockwood CA Jr. Wilkins KE, Beaty JH, eds. Rockwood and Green’s Fractures in Children, 4th ed, vol. 3. Philadelphia: Lippincott-Raven, 1996:515.)

 

RADIUS AND ULNA SHAFT FRACTURES

Classification

Descriptive

• Location: proximal, middle, distal third
• Type: plastic deformation, incomplete (greenstick), compression (torus or buckle), or complete

• Displacement
• Angulation

Nonoperative Treatment

• Gross deformity should be corrected on presentation to limit injury to soft tissues. The extremity should be splinted for pain relief and for prevention of further injury if closed reduction will be delayed.

• The extent and type of fracture and the child’s age are factors that determine whether reduction can be carried out with sedation, local anesthesia, or general anesthesia.

• Finger traps may be applied with weights to aid in reduction.

• Closed reduction and application of a well-molded (both three-point and interosseous molds) long arm cast or splint should be performed for most fractures, unless the fracture is open, unstable, irreducible, or associated with compartment syndrome.

• Exaggeration of the deformity (often >90 degrees) should be performed to disengage the fragments. The angulated distal fragment may then be apposed onto the end of the proximal fragment, with simultaneous correction of rotation (Fig. 22).

• Reduction should be maintained with pressure on the side of the intact periosteum (concave side).

Figure 22. Top: Traction and counteraction of the thumb is used to increase the deformity. Center: With traction still maintained, the thumb slips farther distally to correct the angulation. It is best to avoid disrupting the periosteum, but on occasion this is necessary. Bottom: Ulnar or radial deviation can also be corrected by traction and thumb pressure. (Redrawn from Weber BG, Brunner C, Freuler F. Treatment of Fractures in Children and Adolescents. New York: Springer-Verlag, 1980.)

• Because of deforming muscle forces, the level of the fracture determines forearm rotation of immobilization:

• Proximal third fractures: supination

• Middle third fractures: neutral

• Distal third fractures: pronation

• The cast should be molded into an oval to increase the width of the interosseous space and bivalved if forearm swelling is a concern. The arm should be elevated (Fig. 23).

 

Figure 23. While the cast hardens, it is pressed together by both hands to form an oval. This increases the width of the interosseus space. Traction should be released gradually while this is done. (Redrawn from Weber BG, Brunner C, Freuler F. Treatment of Fractures in Children and Adolescents. New York: Springer-Verlag, 1980.)

• The cast should be maintained for 4 to 6 weeks until radiographic evidence of union has occurred. Conversion to a short arm cast may be undertaken at 3 to 4 weeks if healing is adequate.

• Acceptable deformity:

• Angular deformities: Correction of 1 degree per month, or 10 degrees per year results from physeal growth. Exponential correction occurs over time; therefore, increased correction occurs for greater deformities.

• Rotational deformities: These do not appreciably correct.

• Bayonet apposition: A deformity ≤1 cm is acceptable and will remodel if the patient is <8 to 10 years old.

• In patients >10 years of age, no deformity should be accepted.

• Plastic deformation: Children <4 years or with deformities <20 degrees usually remodel and can be treated with a long arm cast for 4 to 6 weeks until the fracture site is nontender. Any plastic deformation should be corrected that (1) prevents reduction of a concomitant fracture, (2) prevents full rotation in a child >4 years, or (3) exceeds 20 degrees.

• General anesthesia is typically necessary, because forces of 20 to 30 kg are usually required for correction.

• The apex of the bow should be placed over a well-padded wedge, with application of a constant force for 2 to 3 minutes followed by application of a well-molded long arm cast.

• The correction should have less than 10 to 20 degrees of angulation.

• Greenstick fractures: Nondisplaced or minimally displaced fractures may be immobilized in a well-molded long arm cast. They should be slightly overcorrected to prevent recurrence of deformity.

• Completing the fracture decreases the risk of recurrence of the deformity; however, reduction of the displaced fracture may be more difficult. Therefore, it may be beneficial to carefully fracture the intact cortex while preventing displacement. A well-molded long arm cast should then be applied.

 

Operative Indications

• Unstable/unacceptable fracture reduction after closed reduction

• Open fracture/compartment syndrome

• Floating elbow

• Refracture with displacement

• Segmental fracture

• Age (girls >14 years old, boys >15 years old)

Surgical stabilization of pediatric forearm fractures is required in 1.5% to 31% of cases.

Operative Treatment

• Intramedullary fixation: Percutaneous insertion of intramedullary rods or wires may be used for fracture stabilization. Typically, flexible rods are used or rods with inherent curvature to permit restoration of the radial bow.

• The radius is reduced first, with insertion of the rod just proximal to the radial styloid after visualization of the two branches of the superficial radial nerve.

• The ulna is then reduced, with insertion of the rod either antegrade through the olecranon or retrograde through the distal metaphysis, with protection of the ulnar nerve.

• Postoperatively, a volar splint is placed for 4 weeks. The hardware is left in place for 6 to 9 months, at which time removal may take place, provided solid callus is present across the fracture site and the fracture line is obliterated.

• Plate fixation: Severely comminuted fractures or those associated with segmental bone loss are ideal indications for plate fixation, because in these patterns rotational stability is needed. Plate fixation is also used in cases of forearm fractures in skeletally mature individuals.

• Ipsilateral supracondylar fractures: When associated with forearm fractures, a “floating elbow” results. These may be managed by conventional pinning of the supracondylar fracture followed by plaster immobilization of the forearm fracture.

Complications

• Refracture: This occurs in 5% of patients and is more common after greenstick fractures and after plate removal.

• Malunion: This is a possible complication.

• Synostosis: Rare complication in children. Risk factors include high-energy trauma, surgery, repeated manipulations, proximal fractures, and head injury.

• Compartment syndrome: One should always bivalve the cast after a reduction.

• Nerve injury: Median, ulnar and posterior interosseous nerve (PIN) nerve injuries have all been reported. There is an 8.5% incidence of iatrogenic injury in fractures that are surgically stabilized.

MONTEGGIA FRACTURE

• This is a proximal ulna fracture with associated dislocation of the radial head.

• Comprises 0.4% of all forearm fractures in children.

• The peak incidence is between 4 and 10 years of age.

• Ulna fracture is usually located at the junction of the proximal and middle thirds.

• Bado classification of Monteggia fractures (Fig. 24):

 

Figure 24. Bado classification. (A) Type I (anterior dislocation): The radial head is dislocated anteriorly and the ulna has a short oblique or greenstick fracture in the diaphyseal or proximal metaphyseal area. (B) Type II (posterior dislocation): The radial head is posteriorly and posterolaterally dislocated; the ulna is usually fractured in the metaphysis in children. (C) Type III (lateral dislocation): There is lateral dislocation of the radial head with a greenstick metaphyseal fracture of the ulna. (D) Type IV (anterior dislocation with radius shaft fracture): The pattern of injury is the same as with a Type I injury, with the inclusion of a radius shaft fracture below the level of the ulnar fracture. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Type I:	Anterior dislocation of the radial head with fracture of ulna diaphysis at any level with anterior angulation; 70% of cases; may occur from a direct blow, hyperpronation, or hyperextension
Type II:	Posterior/posterolateral dislocation of the radial head with fracture of ulna diaphysis with posterior angulation; 3% to 6% of cases; a variant of posterior elbow dislocation when the anterior cortex of the ulna is weaker than the elbow ligaments
Type III:	Lateral/anterolateral dislocation of the radial head with fracture of ulna metaphysis; 23% of cases (ulna fracture usually greenstick); occurs with varus stress on an outstretched hand planted firmly against a fixed surface
Type IV:	Anterior dislocation of the radial head with fractures of both radius and ulna within proximal third at the same level; 1% to 11% of cases

MONTEGGIA FRACTURE EQUIVALENTS (FIG. 25)

Figure 25. Type I Monteggia equivalents: 1, isolated anterior radial head dislocation; 2, ulnar fracture with fracture of the radial neck; 3, isolated radial neck fractures; 4, elbow (ulnohumeral) dislocation with or without fracture of the proximal radius; 5, supracondylar fracture in association with type I injury. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)
Type I:	Isolated radial head dislocation
Type II:	Ulna and proximal radius (neck) fracture
Type III:	Isolated radial neck fracture
Type IV:	Elbow dislocation (ulnohumeral)

• Treatment: Based on the type of ulna fracture rather than on the Bado type. Plastic deformation is treated with reduction of ulnar bow. Incomplete fractures are treated with closed reduction and casting (Types I and III are more stable with immobilization in 100 to 110 degrees of flexion and full supination). Complete fractures are treated with Kirschner wires or intramedullary fixation if one is unable to reduce the radial head or ulna.

• Ten degrees of angulation are acceptable in children <10 years old, provided reduction of radial head is adequate.

• Complications:
• Nerve injury: There is a 10% to 20% incidence of radial nerve injury (most common in Types I and III).

• Myositis ossificans occurs in 7% of cases.

 

GALEAZZI FRACTURE

 

• A middle to distal third radius fracture, with intact ulna, and disruption of the DRUJ. A Galeazzi equivalent is a distal radial fracture with a distal ulnar physeal fracture (more common).

• This injury is rare in children; 3% of distal radius fractures have concurrent DRUJ disruption.

• Peak incidence is between ages 9 and 12 years.

• Classified by position of radius (Fig. 26)

 

 

Figure 26. Walsh classification. (A) The most common pattern, in which there is dorsal displacement with supination of the distal radius (open arrow). The distal ulna (black arrow) lies volar to the dorsally displaced distal radius. (B) The least common pronation pattern. There is volar or anterior displacement of the distal radius (open arrow), and the distal ulna lies dorsal (black arrow). (From Walsh HPJ, McLaren CANP. Galeazzi fractures in children. J Bone Joint Surg Br 1987;69:730–733.)

 

Type I:	Dorsal displacement of distal radius, caused by supination force. Reduce with forced pronation and dorsal to volar force on the distal radius.
Type II:	Volar displacement, caused by pronation. Reduce with supination and volar to dorsal force on the distal radius.

• The operative indication is a failure to maintain reduction. This is treated with cross pinning, intramedullary pins, or plating.

• Complications:
• Malunion: This results most frequently from persistent ulnar subluxation.

• Ulnar physeal arrest: Occurs in 55% of Galeazzi equivalent fractures.

DISTAL RADIUS FRACTURES

Physeal Injuries

• Salter-Harris Types I and II: Gentle closed reduction is followed by application of a long arm cast or sugar tong splint with the forearm pronated (Fig. 27); 50% apposition with no angular or rotational deformity is acceptable. Growth arrest can occur in 25% of patients if two or more manipulations are attempted. Open reduction is indicated if the fracture is irreducible (periosteum or pronator quadratus may be interposed).

Figure 27. Acceptable method of closed reduction of distal physeal fractures of the radius. (A) Position of the fracture fragments as finger trap traction with countertraction is applied (arrows). (B) Often with traction alone the fracture will reduce without external pressure (arrows). (C) If the reduction is incomplete, simply applying direct pressure over the fracture site in a distal and volar direction with the thumb often completes the reduction while maintaining traction. This technique theoretically decreases the shear forces across the physis during the reduction process. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Salter-Harris Type III: Anatomic reduction is necessary. Open reduction and internal fixation with smooth pins or screws parallel to the physis is recommended if the fracture is inadequately reduced.

• Salter-Harris Types IV and V: Rare injuries. Open reduction and internal fixation is indicated if the fracture is displaced; growth disturbance is likely.

• Complications

• Physeal arrest may occur from original injury, late reduction (>7 days after injury), or multiple reduction attempts. It may lead to ulnar positivity.

• Ulnar styloid nonunion is often indicative of a TFCC tear. The styloid may be excised and the TFCC repaired.

• Carpal tunnel syndrome: Decompression may be indicated.

Table 45.1. Acceptable angular corrections in degrees

Sagittal Plane   Age (yr) Boys Girls Frontal Plane 4 – 9 20 15 15 9 – 11 15 10 5 11 – 13 10 10 0 >13 5 0 0 Acceptable residual angulation is that which will result in total radiographic and functional correction. (Courtesy B. deCourtivron, MD. Centre Hospitalie Universitaire de Tours. Tours, France; from: Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

Metaphyseal Injuries

• Classified by the direction of displacement, involvement of the ulna, and the biomechanical pattern (torus, incomplete, complete).

• Treatment
• Torus fractures: If only one cortex is involved, then the injury is stable and may be treated with protected immobilization for pain relief. Bicortical injuries should be treated in a long arm cast.

• Incomplete (greenstick) fractures (Table 45.1): These have a greater ability to remodel in the sagittal plane than in the frontal plane. Closed reduction with completion of the fracture is indicated to reduce the risk of subsequent loss of reduction. The patient should be placed in supination to reduce the pull of the brachioradialis in a long arm cast.

• Complete fractures: Finger traps may hinder reduction because the periosteum may tighten with traction. The patient should be placed in a well molded long arm cast for 3 to 4 weeks (Fig. 28). Indications for percutaneous pinning include loss of reduction, excessive local swelling preventing placement of a well-molded cast, floating elbow, and multiple manipulations. Open reduction is indicated if the fracture is irreducible (<1% of all distal radius fractures), if the fracture is open, or if the patient has compartment syndrome.

Figure 28. Three-point molding. Top: Three-point molding for dorsally angulated (apex volar) fractures, with the proximal and distal points on the dorsal aspect of the cast and the middle point on the volar aspect just proximal to the fracture site. Bottom: For volar angulated fractures, where the periosteum is intact volarly and is disrupted on the dorsal surface, three-point molding is performed with the proximal and distal points on the volar surface of the cast and the middle point just proximal to the fracture site on the dorsal aspect of the cast. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Complications
• Malunion: Loss of reduction may occur in up to 30% of metaphyseal fractures with bayonet opposition. Residual malangulation of more than 20% may result in loss of forearm rotation.

• Nonunion: This rare complication is usually indicative of an alternate pathologic state

• Refracture: Usually results from an early return to activity (before 6 weeks).

• Growth disturbance: The average disturbance of growth is 3 mm (either overgrowth or undergrowth) with maximal overgrowth in 9 to 12 year olds.

• Neurovascular injuries: One needs to avoid extreme positions of immobilization.

 

Pediatric Wrist and Hand

INJURIES TO THE CARPUS

Epidemiology

• Rare, although carpal injuries may be underappreciated owing to difficulties in examining an injured child and the limited ability of plain radiographs to detail the immature skeleton.

• The adjacent physis of the distal radius is among the most commonly injured; this is protective of the carpus as load transmission is diffused by injury to the distal radial physis, thus partially accounting for the rarity of pediatric carpal injuries.

Anatomy

• The cartilaginous anlage of the wrist begins as a single mass; by the tenth week, this transforms into eight distinct masses, each in the contour of its respective mature carpal bone.

• The appearance of ossification centers of the carpal bones ranges from 6 months for the capitate to 8 years of age for the pisiform. The order of appearance of the ossification centers is very consistent: capitate, hamate, triquetrum, lunate, scaphoid, trapezium, trapezoid, and pisiform (Fig. 29).

• The ossific nuclei of the carpal bones are uniquely protected by cartilaginous shells. As the child matures, a “critical bone-to-cartilage ratio” is reached, after which carpal fractures are increasingly common (adolescence).

Figure 29. The age at the time of appearance of the ossific nucleus of the carpal bones and distal radius and ulna. The ossific nucleus of the pisiform (not shown) appears at about 6 to 8 years of age. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Mechanism of Injury

• The most common mechanism of carpal injury in children is direct trauma to the wrist.

• Indirect injuries result from falls onto the outstretched hand, with consequent axial compressive force with the wrist in hyperextension. In children, injury by this mechanism occurs from higher-energy mechanisms, such as falling off a moving bicycle or fall from a height.

Clinical Evaluation

• The clinical presentation of individual carpal injuries is variable, but in general, the most consistent sign of carpal injury is well-localized tenderness. In the agitated child, however, appreciation of localized tenderness may be difficult, because distal radial pain may be confused with carpal tenderness.

• A neurovascular examination is important, with documentation of distal sensation in median, radial, and ulnar distributions, appreciation of movement of all digits, and assessment of distal capillary refill.

• Gross deformity may be present, ranging from displacement of the carpus to prominence of individual carpal bones.

Radiographic Evaluation

• Anteroposterior (AP) and lateral views of the wrist should be obtained.

• Comparison views of the uninjured, contralateral wrist may be helpful.

Scaphoid Fracture

• The scaphoid is the most commonly fractured carpal bone.

• The peak incidence occurs at age 15 years; injuries in the first decade are extremely rare, owing to the abundant cartilaginous envelope.

• Unlike adults, the most common mechanism is direct trauma, with extraarticular fractures of the distal one-third the most common. Proximal pole fractures are rare and typically result from scapholunate ligament avulsion.

• Clinical evaluation: Patients present with wrist pain and swelling, with tenderness to deep palpation overlying the scaphoid and anatomic snuffbox. The snuffbox is typically obscured by swelling.

• Radiographic evaluation: The diagnosis can usually be made on the basis of AP and lateral views of the wrist. Oblique views and “scaphoid views,” or views of the scaphoid in radial and ulnar deviation of the wrist, may aid in the diagnosis or assist in further fracture definition. Technetium bone scan, magnetic resonance imaging, computed tomography, and ultrasound evaluation may be used to diagnose occult scaphoid fractures.

Classification (Fig. 30)

Type A:	Fractures of the distal pole
A1:	Extraarticular distal pole fractures
A2:	Intraarticular distal pole fractures
Type B:	Fractures of the middle third (waist fractures)
Type C:	Fractures of the proximal pole.

•  

Figure 30. Three types of scaphoid fractures. (A) Distal third. (B) Middle third. (C) Proximal pole. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

Treatment

• A fracture should be presumed if snuffbox tenderness is present, even if radiographs do not show an obvious fracture. Initial treatment in the emergency setting should consist of a thumb spica splint or cast immobilization if swelling is not pronounced. In the pediatric population, a long arm cast or splint is typically necessary for adequate immobilization. This should be maintained for 2 weeks at which time repeat evaluation should be undertaken.

• For stable, nondisplaced fractures, a long arm cast should be placed with the wrist ieutral deviation and flexion/extension and maintained for 6 to 8 weeks or until radiographic evidence of healing has occurred.

• Displaced fractures in the pediatric population may be initially addressed with closed reduction and percutaneous pinning. Distal pole fractures can generally be reduced by traction and ulnar deviation.

• Residual displacement >1 mm, angulation >10 degrees, or scaphoid fractures in adolescents generally require open reduction and internal fixation. A headless compression screw or smooth Kirschner wires may be used for fracture fixation, with postoperative immobilization consisting of a long arm thumb spica cast for 6 weeks.

Complications

• Delayed union, nonunion, and malunion: These are rare in the pediatric population and may necessitate operative fixation with bone grafting to achieve union.

• Osteonecrosis: Extremely rare in the pediatric population and occurs with fractures of the proximal pole in skeletally mature individuals.

• Missed diagnosis: Clinical suspicion should outweigh normal appearing radiographs, and a brief period of immobilization (2 weeks) can be followed by repeat clinical examination and further radiographic studies if warranted.

Lunate Fracture

• This extremely rare injury occurs primarily from severe, direct trauma (e.g., crush injury).

• Clinical evaluation reveals tenderness to palpation on the volar wrist overlying the distal radius and lunate, with painful range of motion.

• Radiographic evaluation: AP and lateral views of the wrist are often inadequate to establish the diagnosis of lunate fracture because osseous details are frequently obscured by overlapping densities.

• Oblique views may be helpful, but computed tomography, or technetium bone scanning best demonstrate fracture.

• Treatment
• Nondisplaced fractures or unrecognized fractures generally heal uneventfully and may be recognized only in retrospect. When diagnosed, they should be treated in a short arm cast or splint for 2 to 4 weeks until radiographic and symptomatic healing occurs.

• Displaced or comminuted fractures should be treated surgically to allow adequate apposition for formation of vascular anastomoses. This may be achieved with open reduction and internal fixation, although the severity of the injury mechanism typically results in concomitant injuries to the wrist that may result in growth arrest.

• Complications
• Osteonecrosis: Referred to as “lunatomalacia” in the pediatric population, this occurs in children less than 10 years of age. Symptoms are rarely dramatic, and radiography reveals mildly increased density of the lunate with no change in morphology. Immobilization of up to 1 year may be necessary for treatment, but it usually results in good functional and symptomatic recovery.

 

Triquetrum Fracture

• Extremely rare, but the true incidence unknown owing to the late ossification of the triquetrum, with potential injuries unrecognized.

• The mechanism of fracture is typically direct trauma to the ulnar wrist or avulsion by dorsal ligamentous structures.

• Clinical evaluation reveals tenderness to palpation on the dorsoulnar aspect of the wrist as well as painful range of motion.

• Radiographic evaluation: Transverse fractures of the body can generally be identified on AP views in older children and adolescents. Distraction views may be helpful in these cases.
• Treatment
• Nondisplaced fractures of the triquetrum body or dorsal chip fractures may be treated in a short arm cast or ulnar gutter splint for 2 to 4 weeks when symptomatic improvement occurs.

• Displaced fractures may be amenable to open reduction and internal fixation.

Pisiform Fracture

• No specific discussions of pisiform fractures in the pediatric population exist in the literature.

• Direct trauma causing a comminuted fracture or a flexor carpi ulnaris avulsion may occur in late adolescence.

• Radiographic evaluation is typically unrevealing, because ossification of the pisiform does not occur until age 8 years.

• Treatment is symptomatic only, with immobilization in an ulnar gutter splint until the patient is comfortable.

Trapezium Fracture

• Extremely rare in children and adults.

• The mechanism of injury is axial loading of the adducted thumb, driving the base of the first metacarpal onto the articular surface of the trapezium with dorsal impaction. Avulsion fractures may occur with forceful deviation, traction, or rotation of the thumb. Direct trauma to the palmar arch may result in avulsion of the trapezial ridge by the transverse carpal ligament.

• Clinical evaluation reveals tenderness to palpation of the radial wrist, accompanied by painful range of motion at the first carpometacarpal joint with stress testing.

• Radiographic evaluation: Fractures are difficult to identify because of the late ossification of the trapezium. In older children and adolescents, identifiable fractures may be appreciated on standard AP and lateral views.

• Superimposition of the first metacarpal base may be eliminated by obtaining a Robert view or a true AP view of the first carpometacarpal joint and trapezium.

• Treatment:
• Most fractures are amenable to thumb spica splinting or casting to immobilize the first carpometacarpal joint for 3 to 5 weeks.

• Rarely, severely displaced fractures may require open reduction and internal fixation to restore articular congruity and maintain carpometacarpal joint integrity.

Trapezoid Fracture

• Fractures of the trapezoid in children are extremely rare.

• Axial load transmitted through the second metacarpal may lead to dislocation, more often dorsal, with associated capsular ligament disruption. Direct trauma from blast or crush injuries may cause trapezoid fracture.

• Clinical evaluation demonstrates tenderness proximal to the base of the second metacarpal with painful range of motion of the second carpometacarpal joint.

• Radiographic evaluation: Fractures are difficult to identify secondary to late ossification. In older children and adolescents, they may be identified on the AP radiograph based on a loss of the normal relationship between the second metacarpal base and the trapezoid. Comparison with the contralateral, normal wrist may aid in the diagnosis. The trapezoid, or fracture fragments, may be superimposed over the trapezium or capitate, and the second metacarpal may be proximally displaced.

• Treatment
• Most fractures may be treated with a splint or short arm cast for 3 to 5 weeks.

• Severely displaced fractures may require open reduction and internal fixation with Kirschner wires with attention to restoration of articular congruity.

Capitate Fracture

• Uncommon as an isolated injury owing to its relatively protected position.

• A fracture of the capitate is more commonly associated with greater arc injury pattern (transscaphoid, transcapitate perilunate fracture-dislocation). A variation of this is the “naviculocapitate syndrome,” in which the capitate and scaphoid are fractured without associated dislocation.

• The mechanism of injury is typically direct trauma or a crushing force that results in associated carpal or metacarpal fracture. Hyperdorsiflexion may cause impaction of the capitate waist against the lunate or dorsal aspect of the radius.

• Clinical evaluation reveals point tenderness as well as variable painful dorsiflexion of the wrist as the capitate impinges on the dorsal rim of the radius.

• Radiographic evaluation: Fracture can usually be identified on the AP radiograph, with identification of the head of the capitate on lateral views to determine rotation or displacement. Distraction views may aid in fracture definition as well as identification of associated greater arc injuries. Magnetic resonance imaging may assist in evaluating ligamentous disruption.
• Treatment: Splint or cast immobilization for 6 to 8 weeks may be performed for minimally displaced capitate fractures. Open reduction is indicated for fractures with extreme displacement or rotation to avoid osteonecrosis. Fixation may be achieved with Kirschner wires or compression screws.

• Complications
• Midcarpal arthritis: Caused by capitate collapse as a result of displacement of the proximal pole.

• Osteonecrosis: Rare and most often involves severe displacement of the proximal pole. It may result in functional impairment and emphasizes the need for accurate diagnosis and stable reduction.

Hamate Fracture

• There are no specific discussions in the literature concerning hamate fractures in the pediatric population.

• The mechanism of injury typically involves direct trauma to the volar aspect of the ulnar wrist such as may occur with participation in racquet sports, softball, or golf.

• Clinical evaluation: Patients typically present with pain and tenderness over the hamate. Ulnar and mediaeuropathy can also be seen, as well as rare injuries to the ulnar artery.

• Radiographic evaluation: The diagnosis of hamate fracture can usually be made on the basis of the AP view of the wrist. Fracture of the hamate is best visualized on the carpal tunnel or 20-degree supination oblique view (oblique projection of the wrist in radial deviation and semisupination). A hamate fracture should not be confused with an os hamulus proprium, which represents a secondary ossification center.

• Treatment: All hamate fractures should be initially treated with immobilization in a short arm splint or cast unless compromise of neurovascular structures warrants exploration. Excision of fragments is generally not necessary in the pediatric population.

• Complications
• Symptomatic nonunion: May be treated with excision of the nonunited fragment.

• Ulnar or mediaeuropathy: Related to the proximity of the hamate to these nerves and may require surgical exploration and release.

INJURIES TO THE HAND

Epidemiology

• Biphasic distribution: These injuries are seen in toddlers and adolescents. The injuries are typically crush injuries in toddlers and are typically related to sports participation in adolescents.

• The number of hand fractures in children is higher in boys and peaks at 13 years of age, which coincides with participation of boys in organized football.

• The annual incidence of pediatric hand fractures is 26.4 per 10,000 children, with the majority occurring about the metacarpophalangeal joint.

• Hand fractures account for up to 25% of all pediatric fractures.

Anatomy (Fig. 31)

 

Figure 31. Appearance of secondary ossification centers (A). Fusion of secondary centers to the primary centers (F). (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• As a rule, extensor tendons of the hand insert onto epiphyses.

• At the level of the metacarpophalangeal joints, the collateral ligaments originate from the metacarpal epiphysis and inset almost exclusively onto the epiphysis of the proximal phalanx; this accounts for the high frequency of Salter-Harris Type II and III injuries in this region.

• The periosteum of the bones of the pediatric hand is usually well developed and accounts for intrinsic fracture stability in seemingly unstable injuries; this often serves as an aid to achieving or maintaining fracture reduction. Conversely, the exuberant periosteum may become interposed in the fracture site, thus preventing effective closed reduction.

Mechanism of Injury

• The mechanism of hand injuries varies considerably. In general, fracture patterns emerge based on the nature of the traumatic force:

• Nonepiphyseal: torque, angular force, compressive load, direct trauma

• Epiphyseal: avulsion, shear, splitting

• Physeal: shear, angular force, compressive load

Clinical Evaluation

• The child with a hand injury is typically uncooperative because of pain, unfamiliar surroundings, parent anxiety, and “white coat” fear. Simple observation of the child at play may provide useful information concerning the location and severity of injury. Game playing (e.g., “Simon says”) with the child may be utilized for clinical evaluation.

• History: A careful history is essential because it may influence treatment. This should include:

• Patient age.

• Dominant versus nondominant hand.

• Refusal to use the injured extremity.

• The exact nature of the injury: crush, direct trauma, twist, tear, laceration, etc.

• The exact time of the injury (for open fractures).

• Exposure to contamination: barnyard, brackish water, animal/human bite.

• Treatment provided: cleansing, antiseptic, bandage, tourniquet.

• Physical examination: The entire hand should be exposed and examined for open injuries. Swelling should be noted, as well as the presence of gross deformity (rotational or angular).

• A careful neurovascular examination is critical, with documentation of capillary refill and neurologic status (two point discrimination). If the child is uncooperative and nerve injury is suspected, the “wrinkle test” may be performed. This is accomplished by immersion of the affected digit in warm, sterile water for 5 minutes and observing corrugation of the distal volar pad (absent in the denervated digit).

• Passive and active range of motion of each joint should be determined. Observing tenodesis with passive wrist motion is helpful for assessing digital alignment and cascade.

• Stress testing may be performed to determine collateral ligament and volar plate integrity.

Radiographic Evaluation

• AP, lateral, and oblique radiographs of the affected digit or hand should be obtained. Injured digits should be viewed individually, when possible, to minimize overlap of other digits over the area of interest.

• Stress radiographs may be obtained in cases in which ligamentous injury is suspected.

• The examiner must be aware that cartilaginous injury may have occurred despite negative plain radiographs. Treatment must be guided by clinical as well as radiographic factors.

Treatment

General Principles

• “Fight-bite” injuries: Any short, curved laceration overlying a joint in the hand, particularly the metacarpal-phalangeal joint, must be suspected of having been caused by a tooth. These injuries must be assumed to be contaminated with oral flora and should be addressed with broad-spectrum antibiotics.

• Most pediatric hand fractures are treated nonoperatively, with closed reduction using conscious sedation or regional anesthesia (e.g., digital block). Hematoma blocks or fracture manipulation without anesthesia should be avoided in younger children.

• Finger traps may be utilized with older children or adolescents but are generally poorly tolerated in younger children.

• The likelihood of iatrogenic physeal injury substantially increases with repeated, forceful manipulation, especially when involving late (>5 to 7 days) manipulation of a paraphyseal fracture.

• Immobilization may consist of short arm splints (volar, dorsal, ulnar gutter, etc.) or long arm splints in younger patients to enhance immobilization. With conscientious follow-up and cast changes as indicated, immobilization is rarely necessary beyond 4 weeks.

• Operative indications include: unstable fractures, in which the patient may benefit from percutaneous Kirschner wire fixation; open fractures, which may require irrigation, debridement, and secondary wound closure; and fractures in which reduction is unattainable by closed means—these may signify interposed periosteum or soft tissue that requires open reduction.

• Subungual hematomas that occupy >50% of the nailplate should be evacuated with the use of a needle, cautery tip, or heated paper clip. DaCruz et al. reported a high incidence of late nail deformities associated with failure to decompress subungual hematomas.

• Nailbed injuries should be addressed with removal of the compromised nail, repair of the nailbed with 6-0 or 7-0 absorbable suture, and retention of the nail under the nailfold as a biologic dressing to protect the healing nailbed. Alternatively, commercially made stents are available for use as dressings.

Management of Specific Fracture Patterns

METACARPALS

• Pediatric metacarpal fractures are classified as follows:

Type A: Epiphyseal and Physeal Fractures

• Fractures include the following:

• Epiphyseal fractures

• Physeal fractures: Salter Harris Type II fractures of the fifth metacarpal most common

• Collateral ligament avulsion fractures

• Oblique, vertical, and horizontal head fractures

• Comminuted fractures

• Boxer’s fractures with an intraarticular component

• Fractures associated with bone loss

• Most require anatomic reduction (if possible) to reestablish joint congruity and to minimize posttraumatic arthrosis.

• Stable fracture reductions may be splinted in the protected position  consisting of metacarpophalangeal flexion >70 degrees and interphalangeal joint extension to minimize joint stiffness.

• Percutaneous pinning may be necessary to obtain stable reduction; if possible, the metaphyseal component (Thurston-Holland fragment) should be included in the fixation.

• Early range of motion is essential.

Type B: Metacarpal Neck

• Fractures of the fourth and fifth metacarpal necks are commonly seen as pediatric analogs to boxer’s fractures in adults.

• The degree of acceptable deformity varies according to the metacarpal injured, especially in adolescents:

• More than 15-degree angulation for the second and third metacarpals is unacceptable.

• More than 40- to 45-degree angulation for the fourth and fifth metacarpals is unacceptable.

• These are typically addressed by closed reduction using the Jahss maneuver by flexing the metacarpophalangeal joint to 90 degrees and placing an axial load through the proximal phalanx. This is followed by splinting in the “protected position.”

• Unstable fractures require operative intervention with either percutaneous pins (may be intramedullary or transverse into the adjacent metacarpal) or plate fixation (adolescents).

Type C: Metacarpal Shaft

• Most of these fractures may be reduced by closed means and splinted in the protected position.

• Operative indications include unstable fractures, rotational deformity, dorsal angulation >10 degrees for second and third metacarpals, and >20 degrees for fourth and fifth metacarpals, especially for older children and adolescents in whom significant remodeling is not expected.

• Operative fixation may be achieved with closed reduction and percutaneous pinning (intramedullary or transverse into the adjacent metacarpal). Open reduction is rarely indicated, although the child presenting with multiple, adjacent, displaced metacarpal fractures may require reduction by open means.

Type D: Metacarpal Base

• The carpometacarpal joint is protected from frequent injury owing to its proximal location in the hand and the stability afforded by the bony congruence and soft tissue restraints.

• The fourth and fifth carpometacarpal joints are more mobile than the second and third; therefore, injury to these joints is uncommon and usually results from high-energy mechanisms.

• Axial loading from punching mechanisms typically results in stable buckle fractures in the metaphyseal region.

• Closed reduction using regional or conscious sedation and splinting with a short arm ulnar gutter splint may be performed for the majority of these fractures, leaving the proximal interphalangeal joint mobile.

• Fracture-dislocations in this region may result from crush mechanisms or falls from a height; these may initially be addressed with attempted closed reduction, although transverse metacarpal pinning is usually necessary for stability. Open reduction may be necessary, especially in cases of multiple fracture-dislocations at the carpometacarpal level.

THUMB METACARPAL

• Fractures are uncommon and are typically related to direct trauma.

• Metaphyseal and physeal injuries are the most common fracture patterns.

• Structures inserting on the thumb metacarpal constitute potential deforming forces:

• Opponens pollicis: broad insertion over metacarpal shaft and base that displaces the distal fragment into relative adduction and flexion

• Abductor pollicis longus: multiple sites of insertion including the metacarpal base, resulting in abduction moment in cases of fracture-dislocation

• Flexor pollicis brevis: partial origin on the medial metacarpal base, resulting in flexion and apex dorsal angulation in metacarpal shaft fractures

• Adductor pollicis: possible adduction of the distal fragment

Thumb Metacarpal Head and Shaft Fractures

• These typically result from direct trauma.

• Closed reduction is usually adequate for the treatment of most fractures, with postreduction immobilization consisting of a thumb spica splint or cast.

• Anatomic reduction is essential for intraarticular fractures and may necessitate the use of percutaneous pinning with Kirschner wires.

Thumb Metacarpal Base Fractures

These are subclassified as follows (Fig. 32):

 

Figure 32. Classification of thumb metacarpal fractures. (A) Metaphyseal fracture. (B,C) Salter-Harris Type II physeal fractures with lateral or medial angulation. (D) Salter-Harris Type III fracture (pediatric Bennett fracture). (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• Type A: fractures distal to the physis

• They are often transverse or oblique, with apex-lateral angulation and an element of medial impaction.

• They are treated with closed reduction with extension applied to the metacarpal head and direct pressure on the apex of the fracture, then immobilized in a thumb spica splint or cast for 4 to 6 weeks.

• Up to 30 degrees of residual angulation may be accepted in younger children.

• Unstable fractures may require percutaneous Kirschner wire fixation, often with smooth pins to cross the physis. Transcarpometacarpal pinning may be performed but is usually reserved for more proximal fracture patterns.

• Type B: Salter-Harris Type II fracture, metaphyseal medial

• The shaft fragment is typically angulated laterally and displaced proximally owing to the pull of the abductor pollicis longus; adduction of the distal fragment is common because of the pull of the adductor pollicis.

• Anatomic reduction is essential to avoid growth disturbance.

• Closed reduction followed by thumb spica splinting is initially indicated, with close serial follow-up. With maintenance of reduction, immobilization should be continued for 4 to 6 weeks.

• Percutaneous pinning is indicated for unstable fractures with capture of the metaphyseal fragment if possible. Alternatively, transmetacarpal pinning to the second metacarpal may be necessary. Open reduction may be required for anatomic restoration of the physis.

• Type C: Salter-Harris Type II fracture, metaphyseal lateral

• These are similar to Type B fractures, but they are less common and typically result from more significant trauma, with consequent apex medial angulation.

• Periosteal buttonholing is common and may prevent anatomic reduction.

• Open reduction is frequently necessary for restoration of anatomic relationships.

• Type D: intraarticular Salter-Harris Type III or IV fractures

• These are the pediatric analogs to the adult Bennett fracture.

• They are rare, with deforming forces similar to Type B fractures, with the addition of lateral subluxation at the level of the carpometacarpal articulation caused by the intraarticular component of the fracture.

• Nonoperative methods of treatment widely variable in results. Most consistent results are obtained with open reduction and percutaneous pinning or internal fixation in older children.

• Severe comminution or soft tissue injury may be initially addressed with oblique skeletal traction.

• External fixation may be used for contaminated open fractures with potential bone loss.

PHALANGES (FIG. 33)

• The physes are located at the proximal aspect of the phalanges.

• The collateral ligaments of the proximal and distal interphalangeal joints originate from the collateral recesses of the proximal bone and insert onto both the epiphysis and metaphysis of the distal bone and volar plate.

• The volar plate originates from the metaphyseal region of the phalangeal neck and inserts onto the epiphysis of the more distal phalanx.

• The extensor tendons insert onto the dorsal aspect of the epiphysis of the middle and distal phalanges.

• The periosteum is typically well developed and exuberant, often resisting displacement and aiding reduction, but occasionally interposing at the fracture site and preventing adequate reduction.

Proximal and Middle Phalanges

Figure 33. Anatomy about the distal phalanx. (A) The skin, nail, and extensor apparatus share a close relationship with the bone of the distal phalanx. Specific anatomic structures at the terminal aspect of the digit are labeled. (B) This lateral view of the nail demonstrates the tendon insertions and the anatomy of the specialized nail tissues. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

 

 

Pediatric fractures of the proximal and middle phalanges are subclassified as follows:

• Type A: physeal
• Of pediatric hand fractures, 41% involve the physis. The proximal phalanx is the most frequently injured bone in the pediatric population.

• The collateral ligaments insert onto the epiphysis of the proximal phalanx; in addition to the relatively unprotected position of the physis at this level, this contributes to the high incidence of physeal injuries.

• A pediatric “gamekeeper’s” thumb is a Salter-Harris Type III avulsion fracture, with the ulnar collateral ligament attached to an epiphyseal fragment of the proximal aspect of the proximal phalanx.

• Treatment is initially by closed reduction and splinting in the protected position.

• Unstable fractures may require percutaneous pinning. Fractures with >25% articular involvement or >1.5 mm displacement require open reduction with internal fixation with Kirschner wires or screws.

• Type B: shaft
• Shaft fractures are not as common as those surrounding the joints.

• Proximal phalangeal shaft fractures are typically associated with apex volar angulation and displacement, created by forces of the distally inserting central slip and lateral bands coursing dorsal to the apex of rotation, as well as the action of the intrinsics on the proximal fragment pulling it into flexion.

• Oblique fractures may be associated with shortening and rotational displacement. This must be recognized and taken into consideration for treatment.

• Closed reduction with immobilization in the protected position for 3 to 4 weeks is indicated for the majority of these fractures.

• Residual angulation >30 degrees in children <10 years of age, >20 degrees in children >10 years of age, or any malrotation requires operative intervention, consisting of closed reduction and percutaneous crossed pinning. Intramedullary pinning may allow rotational displacement.

• Type C: neck (Fig. 34)
• Fractures through the metaphyseal region of the phalanx are commonly associated with door-slamming injuries.

Figure 34. Phalangeal neck fractures often are unstable and rotated. These fractures are difficult to reduce and control by closed means because of the forces imparted by the volar plate and ligaments. (From Wood BE. Fractures of the hand in children. Orthop Clin North Am 1976;7:527–534.)

• Rotational displacement and angulation of the distal fragment are common, because the collateral ligaments typically remain attached distal to the fracture site. This may allow interposition of the volar plate at the fracture.

• Closed reduction followed by splinting in the protected position for 3 to 4 weeks may be attempted initially, although closed reduction with percutaneous crossed pinning is usually required.

• Type D: intraarticular (condylar)
• These arise from a variety of mechanisms, ranging from shear or avulsion resulting in simple fractures to combined axial and rotational forces that may result in comminuted, intraarticular T- or Y-type patterns.

• Open reduction and internal fixation are usually required for anatomic restoration of the articular surface. This operation is most often performed through a lateral or dorsal incision, with fixation using Kirschner wires or miniscrews.

Distal Phalanx

• These injuries are frequently associated with soft tissue or nail compromise and may require subungual hematoma evacuation, soft tissue reconstructive procedures, or nailbed repair.

• Pediatric distal phalangeal fractures are subclassified as follows:

• Physeal
• Dorsal mallet injuries (Fig. 35)

Type A:	Salter-Harris Type I or II injuries
Type B:	Salter-Harris Type III or IV injuries
Type C:	Salter-Harris Type I or II associated with joint dislocation
Type D:	Salter-Harris fracture associated with extensor tendon avulsion

 

Figure 35. (A–D) Malletequivalent physeal fracture types. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.)

• A mallet finger may result from a fracture of the dorsal lip with disruption of the extensor tendon. Alternatively, a mallet finger may result from a purely tendinous disruption and may therefore not be radiographically apparent.

• Treatment of Type A and nondisplaced or minimally displaced type B injuries is full-time extension splinting for 4 to 6 weeks.

• Type C, D, and displaced Type B injuries typically require operative management. Type B injuries are usually amenable to Kirschner wire fixation with smooth pins. Type C and D injuries generally require open reduction and internal fixation.

• Volar (reverse) mallet injuries
• These are associated with flexor digitorum profundus rupture (“jersey finger:” seen in football and rugby players, most commonly involving the ring finger).

• Treatment is primary repair using heavy suture, miniscrews, or Kirschner wires. Postoperative immobilization is continued for 3 weeks.
• Extraphyseal

Type A:	Transverse diaphyseal
Type B:	Longitudinal splitting
Type C:	Comminuted

 

• The mechanism of injury is almost always direct trauma.

• Nailbed injuries must be recognized and addressed.

• Treatment is typically closed reduction and splinting for 3 to 4 weeks with attention to concomitant injuries. Unstable injuries may require percutaneous pinning, either longitudinally from the distal margin of the distal phalanx or across the distal interphalangeal joint (uncommon) for extremely unstable or comminuted fractures.

Complications

• Impaired nail growth: Failure to repair the nailbed adequately may result in germinal matrix disturbance that causes anomalous nail growth. This is frequently a cosmetic problem, but it may be addressed with reconstructive procedures if pain, infection, or hygiene is an issue.

• Extensor lag: Despite adequate treatment, extensor lag up to 10 degrees is common, although not typically of functional significance. This occurs most commonly at the level of the proximal interphalangeal joint secondary to tendon adherence. Exploration, release, and or reconstruction may result in further cosmetic or functional disturbance.

• Malunion: Apex dorsal angulation can disturb intrinsic balance and also can result in prominence of metacarpal heads in palm with pain on gripping. Rotational or angulatory deformities, especially of the second and third metacarpals, may produce functional and cosmetic disturbances, thus emphasizing the need to maintain as near an anatomic relationship as possible.

• Nonunion: Uncommon but may occur especially with extensive soft tissue injury and bone loss, as well as in open fractures with gross contamination and infection.

• Infection, osteomyelitis: Grossly contaminated wounds require meticulous debridement, appropriate antibiotic coverage, and possible delayed closure.

• Metacarpophalangeal joint extension contracture: This may result if splinting is not in the protected position (i.e., metacarpophalangeal joints at >70 degrees), owing to soft tissue contracture.