PEDIATRIC ANKLE

EPIDEMIOLOGY

• Ankle injuries account for up to 18% of all physeal injuries; they are third in frequency following phalangeal and distal radius physeal injuries.

  • Fifty-eight percent of ankle physeal injuries occur during athletic participation.

  • They represent 10% to 40% of all injuries in skeletally immature athletes.

  • Tibial physeal fractures are most common from 8 to 15 years of age.

  • Fibular physeal injuries are most common from 8 to 14 years of age.

• Ligamentous injuries are rare in children because their ligaments are stronger relative to the physis.

• After age 15 to 16 years, see adult fracture pattern.

  ANATOMY

• The ankle is a modified hinge joint stabilized by medial and lateral ligamentous complexes. All ligaments attach distal to the physes of the tibia and fibula—important in the pathoanatomy of pediatric ankle fracture patterns.

• The distal tibial ossific nucleus appears between the ages of 6 and 24 months; it fuses with the tibial shaft at about age 15 years in girls and 17 years in boys. Over an 18-month period, the lateral portion of the distal tibial physis remains open while the medial part has closed.

• The distal fibular ossific nucleus appears at the age of 9 to 24 months and unites with the fibula shaft 12 to 24 months after tibial physis closure.

• Secondary ossification centers occur and can be confused with a fracture of either the medial or lateral malleolus; they are often bilateral.

• The unique fracture patterns occur with the fusion of tibial physis from central to anteromedial to posteromedial and finally to lateral.

  MECHANISM OF INJURY

• Direct: Trauma to the ankle from a fall, motor vehicle accident, or pedestrian–motor vehicle accident.

• Indirect: Axial force transmission through the forefoot and hindfoot or rotational force of the body on a planted foot; it may be secondary to a fall or, more commonly, athletic participation.

  CLINICAL EVALUATION

• Patients with displaced ankle fractures typically present with pain and gross deformity, as well as an inability to ambulate.

• Physical examination may demonstrate tenderness, swelling, and ecchymosis.

• Ligamentous instability may be present, but it is usually difficult to elicit on presentation owing to pain and swelling from the acute injury.

• Ankle sprains are a diagnosis of exclusion and should be differentiated from a nondisplaced fracture based on the location of tenderness.

• Neurovascular examination is essential, with documentation of dorsalis pedis and posterior tibial pulses, capillary refill, sensation to light touch and pinprick, and motor testing.

• Dressings and splints placed in the field should be removed and soft tissue conditions assessed, with attention to skin lacerations that may indicate open fracture or fracture blisters that may compromise wound healing.

• The ipsilateral foot, leg, and knee should be examined for concomitant injury.

  RADIOGRAPHIC EVALUATION

• Anteroposterior (AP), lateral, and mortise views of the ankle should be obtained. Tenderness of the proximal fibula warrants appropriate views of the leg.

• Clinical examination will dictate the possible indication for obtaining views of the knee and foot.

• Stress views of the ankle may be obtained to determine possible undisplaced transphyseal fractures.

• The presence of secondary ossification centers (a medial os subtibiale in 20% of patients or a lateral os subfibulare in 1% of patients) should not be confused with fracture, although tenderness may indicate injury.

• A Tillaux fragment represents an osseous fragment from the lateral distal tibia that has been avulsed during injury.

• Computed tomography (CT) is often helpful for evaluation of complex intra-articular fractures, such as the juvenile Tillaux or triplane fracture.

• Magnetic resonance imaging has been used to delineate osteochondral injuries in association with ankle fractures.

  CLASSIFICATION

  Dias and Tachdjian

• Lauge–Hansen principles are followed, incorporating the Salter–Harris classification.

• The typology is simplified by noting the direction of physeal displacement, Salter–Harris type, and location of the metaphyseal fragment.

• The classification aids in determining the proper maneuver for closed reduction (Fig. 51.1).

   

   

   

  Supination–External Rotation (SER)

  Stage I: Salter–Harris type II fracture of the distal tibia with the metaphyseal fragment located posterolaterally; the distal fragment is displaced posteriorly, but the Thurston–Holland fragment is seen on the AP x-ray, which differentiates it from a supination–plantar flexion (SPF) injury.

  Stage II: As external rotation force continues, a spiral fracture of the fibula occurs beginning medially and extending posterosuperiorly; it differs from an adult SER injury.

  Pronation–Eversion–External Rotation (PEER)

• This type comprises 15% to 20% of pediatric ankle fractures.

• Marked valgus deformity occurs.

• Tibial and fibular fractures occur simultaneously.

• Salter–Harris type II fracture of the distal tibial physis is most commonly seen, but type I also occurs; the metaphyseal fragment is located laterally.

• The short oblique distal fibular fracture occurs 4 to 7 cm proximal to the fibula tip.

  Supination–Plantar Flexion (SPF)

• Most commonly, this is a Salter–Harris type II fracture of the distal tibial physis with the metaphyseal fragment located posteriorly; type I Salter–Harris fractures are rare.

• Fibula fracture is rare.

  Supination–Inversion (SI)

• This is the most common mechanism of fracture and has the highest incidence of complications. Stage I: Salter–Harris type I or II fracture of the distal fibular physis is most common because the adduction or supination force avulses the epiphysis; pain is noted along the physis

  when x-rays are negative. This is the most common pediatric ankle fracture.

  Stage II: Salter–Harris type III or IV fracture of the medial tibial physis occurs as the talus wedges into the medial tibial articular surface; rarely, this is a type I or II fracture. These are intra-articular fractures that exhibit the highest rate of growth disturbance (i.e., physeal bar formation).

  Axial Compression (Fig. 51.2)

   

   

   

• A Salter–Harris type V injury to the distal tibia

• A rare injury with poor prognosis secondary to physeal growth arrest

• Diagnosis often delayed until premature physeal closure is found with a leg length discrepancy

  Juvenile Tillaux Fractures (Fig. 51.3)

   

   

   

• These are Salter–Harris type III fractures of the anterolateral tibial epiphysis; they occur in 2.9% of ankle fractures.

• External rotation force causes the anterior tibiofibular ligament to avulse the fragment.

• These fractures occur in the 13- to 16-year-old age group when the central and medial portions of the distal tibial physis have already fused, and the lateral physis remains open (Fig. 51.4).

   

   

   

• Patients with Tillaux fractures are generally older than those with triplane fractures.

• CT scans or tomograms are helpful in distinguishing these injuries from triplane fractures.

  Triplane Fractures

• These occur in three planes: transverse, coronal, and sagittal.

• Fractures are explained by fusion of tibial physis from central to anteromedial to posteromedial and finally to lateral.

• Peak age incidence is 13 to 15 years in boys and 12 to 14 years in girls.

• Mechanism is thought to be external rotation of the foot and ankle.

• Fibula fracture is possible; it is usually oblique from anteroinferior to posterosuperior 4 to 6 cm proximal to the fibula tip.

• CT is valuable in the preoperative assessment.

• Two- and three-part types have been described (Figs. 51.5 and 51.6):

  • Two-part fractures are either medial, in which the coronal fragment is posteromedial, or lateral, in which the coronal fragment is posterolateral.

  • Three-part fractures consist of (1) an anterolateral fragment that mimics the Juvenile Tillaux

    fracture (Salter–Harris type III), (2) the remainder of the physis with a posterolateral spike of the tibial metaphysis, and (3) the remainder of the distal tibial metaphysis.

     

     

     

     

     

     

    TREATMENT‌

    Lateral Ma leolar (Distal Fibula) Fracture

    Salter–Harris Type I or II

• Closed reduction and casting with a short leg walking cast for 4 to 6 weeks is recommended.

  Salter–Harris Type III or IV

• Closed reduction and percutaneous pinning with Kirschner wire fixation is followed by placement of a short leg cast.

• Open reduction may be required for interposed periosteum, with fixation using an intramedullary Kirschner wire perpendicular to the physis.

  Medial Ma leolar (Distal Tibia) Fracture

  Salter–Harris Type I or II

• Closed reduction is the treatment of choice; it is usually attainable unless soft tissue interposition prevents reduction.

• In children <10 years old, some residual angulation is acceptable, because remodeling occurs.

• Open reduction may be necessary for interposed periosteum, with placement of a transmetaphyseal compression screw or Kirschner wire parallel and proximal to the physis.

• A long leg cast for 3 weeks is followed by a short leg walking cast for 3 weeks.

  Salter–Harris Type III or IV

• Anatomic reduction is essential.

• Intra-articular displacement >2 mm is unacceptable; open reduction and internal fixation is indicated.

• Open reduction and internal fixation may be performed through an anteromedial approach with cancellous screw(s) placed parallel below and/or above the physis.

• Postoperative immobilization consists of short leg casting for 6 weeks.

• Weekly x-rays should be obtained for the first several weeks to ensure that the intra-articular fragment does not displace.

  Juvenile Ti laux Fracture

• Closed reduction can be attempted by gentle distraction accompanied by internal rotation of the foot and direct pressure over the anterolateral tibia; reduction may be maintained in a short or long leg cast, depending on the rotational stability. The patient is non–weight bearing for the initial 3 weeks, followed by a short leg walking cast for an additional 3 weeks.

• Unstable injuries may require percutaneous pinning with Kirschner-wire fixation.

• Vertical displacement >2 mm or horizontal displacement >3 to 5 mm are unacceptable and warrants open reduction and internal fixation.

• Open reduction and internal fixation may be achieved via an anterolateral approach with cancellous screw fixation.

• CT may be used to assess reduction.

  Triplane Fracture

• Nondisplaced fractures may be treated in a long leg cast with the knee flexed to 30 degrees for 3 to 4 weeks, followed by an additional 3 weeks in a short leg walking cast.

• Articular displacement >2 mm warrants operative fixation, either by closed reduction and percutaneous pinning or by open reduction and internal fixation using a combination of cancellous screws or Kirschner wires for fixation.

• CT may be used to assess the adequacy of reduction.

• Postoperative immobilization consists of a short or long leg cast (depending on stability of fixation) for 3 to 4 weeks followed by a short leg walking cast for an additional 3 weeks.

  COMPLICATIONS

• Angular deformity: May occur secondary to premature physeal arrest, especially after Salter–Harris type III and IV injuries. Harris growth lines may be seen at 6 to 12 weeks after injury as an indication of growth arrest.

• Varus deformity is most common in sacroiliac (SI) injuries with premature arrest of the medial tibial physis.

• Valgus deformity is seen with distal fibula physeal arrest; it may result from poor reduction or interposed soft tissue.

• Rotational deformities may occur with inadequately reduced triplane fractures; extra-articular rotational deformities may be addressed with derotational osteotomies, but intra-articular fractures cannot.

• Leg length discrepancy: This complicates up to 10% to 30% of cases and is dependent on the age of the patient. Discrepancy of 2 to 5 cm may be treated by epiphysiodesis of the opposite extremity, although skeletally mature individuals may require osteotomy.

• Posttraumatic arthritis: This may occur as a result of inadequate reduction of the articular surface in Salter–Harris types III and IV fractures.

  52

  PEDIATRIC FOOT

   

   

   

  TALUS

  Epidemiology

• It is extremely rare in children (0.01% to 0.08% of all pediatric fractures).

• Most represent fractures through the talar neck.

  Anatomy

• The ossification center of the talus appears at 8 months in utero (Fig. 52.1).

   

   

   

• Two thirds of the talus is covered with articular cartilage.

• The body of the talus is covered superiorly by the trochlear articular surface through which the body weight is transmitted. The anterior aspect is wider than the posterior aspect, which confers intrinsic stability to the ankle.

• Arterial supply to the talus is from two main sources:

  • Artery to the tarsal canal: This arises from the posterior tibial artery 1 cm proximal to the origin of the medial and lateral plantar arteries. It gives off a deltoid branch immediately after its origin that anastomoses with branches from the dorsalis pedis over the talar neck.

  • Artery of the tarsal sinus: This originates from the anastomotic loop of the perforating peroneal and lateral tarsal branches of the dorsalis pedis artery.

• An os trigonum is present in up to 50% of normal feet. It arises from a separate ossification center

  just posterior to the lateral tubercle of the posterior talar process.

  Mechanism of Injury

• Forced dorsiflexion of the ankle from motor vehicle accident or fall represents the most common mechanism of injury in children. This typically results in a fracture of the talar neck.

• Isolated fractures of the talar dome and body have been described but are extremely rare.

  Clinical Evaluation

• Patients typically present with pain on weight bearing on the affected extremity.

• Ankle range of motion is typically painful, especially with dorsiflexion, and may elicit crepitus.

• Diffuse swelling of the hindfoot may be present, with tenderness to palpation of the talus and subtalar joint.

• A neurovascular examination should be performed.

  Radiographic Evaluation

• Standard anteroposterior (AP), mortise, and lateral radiographs of the ankle should be obtained, as well as AP, lateral, and oblique views of the foot.

• Computed tomographic (CT) scanning may be useful for preoperative planning.

• Magnetic resonance imaging (MRI) may be used to identify occult injuries in children <10 years old owing to limited ossification at this age.

  Classification

  Descriptive

  Location: Most talar fractures in children occur through the talar neck.

  Angulation: Usually varus

  Displacement: in millimeters

  Dislocation: Subtalar, talonavicular, or ankle joints

  Pattern: Presence of comminution

  Hawkins Talar Neck Fractures

  This classification is for adults, but it is often used for children.

  Type I: Nondisplaced

  Type II: Displaced with associated subtalar subluxation or dislocation

  Type III: Displaced with associated subtalar and ankle dislocation

  Type IV: Type III with associated talonavicular subluxation or dislocation See Chapter 40 for figures.

  Treatment

  Nonoperative

• Nondisplaced fractures may be managed in a long leg cast with the knee flexed 30 degrees to prevent weight bearing. This is maintained for 6 to 8 weeks with serial radiographs to assess healing status. The patient may then be advanced to weight bearing in a short leg walking cast for an additional 2 to 3 weeks.

  Operative

• This is indicated for displaced fractures.

• Minimally displaced fractures can often be treated successfully with closed reduction with plantar flexion of the forefoot as well as hindfoot eversion or inversion, depending on the displacement.

  • A long leg cast is placed for 6 to 8 weeks; this may require plantar flexion of the foot to maintain reduction. If the reduction cannot be maintained by simple positioning, operative fixation is indicated.

• Displaced fractures are usually amenable to internal fixation using a posterolateral approach and 3.5-mm or 4.0-mm cannulated screws or Kirschner wires placed from a posterior to anterior direction. In this manner, dissection around the talar neck is avoided.

• Postoperatively, the patient is maintained in a short leg cast for 6 to 8 weeks, with removal of wires at 3 to 4 weeks.

  Complications

• Osteonecrosis: This may occur with disruption or thrombosis of the tenuous vascular supply to the talus. This is related to the initial degree of displacement and angulation and, theoretically, the time until fracture reduction. It tends to occur within 6 months of injury.

• Hawkins sign represents subchondral osteopenia in the vascularized, non–weight-bearing talus at 6 to 8 weeks. Although this tends to indicate talar viability, the presence of this sign does not rule out osteonecrosis.

  Type I fractures: 0% to 27% incidence of osteonecrosis reported

  Type II fractures: 42% incidence

  Type III, IV fractures: >90% incidence

   

  CALCANEUS

  Epidemiology

• This is a rare injury (less than 2%), typically involving older children (>9 years) and adolescents.

• Most are extra-articular, involving the apophysis or tuberosity. Most occur secondary to a fall from height.

• Of these, 33% are associated with other injuries, including lumbar vertebral and ipsilateral lower extremity injuries.

  Anatomy

• The primary ossification center appears at 7 months in utero; a secondary ossification center appears at age 10 years and fuses by age 16 years.

• The calcaneal fracture patterns in children differ from that of adults, primarily for three reasons:

  adults.

  Mechanism of Injury

  1. The lateral process, which is responsible for calcaneal impaction resulting in joint depression injury in adults, is diminutive in the immature calcaneus.

  2. The posterior facet is parallel to the ground, rather than inclined as it is in adults.

  3. In children, the calcaneus is composed of an ossific nucleus surrounded by cartilage, which is responsible for the dissipation of the injurious forces that produce classic fracture patterns in

• Most calcaneal fractures occur as a result of a fall or a jump from a height, although typically a lower energy injury occurs than seen with adult fractures.

• Open fractures may result from lawn mower injuries.

  Clinical Evaluation

• Patients are typically unable to walk secondary to hindfoot pain.

• On physical examination, pain, swelling, and tenderness can usually be appreciated at the site of injury.

• Examination of the ipsilateral lower extremity and lumbar spine is essential, because associated injuries are common.

• A careful neurovascular examination should be performed.

• Injury is initially missed in 44% to 55% of cases.

  Radiographic Evaluation

• Dorsoplantar, lateral, axial, and lateral oblique views should be obtained for evaluation of pediatric calcaneal fractures.

• The Böhler tuber joint angle: This is represented by the intersection of two lines: a line from the highest point of the anterior process of the calcaneus to the highest point of the posterior articular surface and a line drawn between the same point on the posterior articular surface and the most superior point of the tuberosity. Normally, this angle is between 25 and 40 degrees; flattening of this angle indicates collapse of the posterior facet (Fig. 52.2).

   

   

   

• Comparison views of the contralateral foot may help detect subtle changes in the Böhler angle.

• Technetium bone scanning may be utilized when calcaneal fracture is suspected but is not appreciated on standard radiographs.

• Computed tomography may aid in fracture definition, particularly in intra-articular fractures in which preoperative planning may be facilitated by three-dimensional characterization of fragments.

  Classification

  Schmidt and Weiner (Fig. 52.3)

  Type I: A. Fracture of the tuberosity or apophysis

  Type II: Fracture of the posterior and/or superior parts of the tuberosity

  Type III: Fracture of the body not involving the subtalar joint

  Type IV: Nondisplaced or minimally displaced fracture through the subtalar joint

  Type V: Displaced fracture through the subtalar joint

  Type VI: Either unclassified (Rasmussen and Schantz) or serious soft tissue injury, bone loss, and loss of the insertions of the Achilles tendon

   

   

   

  Treatment

  Nonoperative

  1. Fracture of the sustentaculum

  2. Fracture of the anterior process

  3. Fracture of the anterior inferolateral process

  4. Avulsion fracture of the body

  5. Tongue type

  6. Joint depression type

• Cast immobilization is recommended for pediatric patients with extra-articular fractures, as well as nondisplaced or minimally displaced intra-articular fractures of the calcaneus. Weight bearing is restricted for 6 weeks, although some authors have suggested that in the case of truly nondisplaced fractures in a very young child, weight bearing may be permitted with cast immobilization.

• Mild degrees of joint incongruity tend to remodel well, although severe joint depression is an indication for operative management.

  Operative

• Operative treatment is indicated for displaced articular fractures, particularly in older children and

  adolescents.

• Displaced fractures of the anterior process of the calcaneus represent relative indications for open reduction and internal fixation, because up to 30% may result in nonunion.

• Anatomic reconstitution of the articular surface is imperative, with lag screw technique for operative fixation.

  Complications

• Posttraumatic osteoarthritis: This may be secondary to residual or unrecognized articular incongruity. Although younger children remodel very well, this emphasizes the need for anatomic reduction and reconstruction of the articular surface in older children and adolescents.

• Heel widening: This is not as significant a problem in children as it is in adults because the mechanisms of injury tend not to be as high energy (i.e., falls from lower heights with less explosive impact to the calcaneus), and remodeling can partially restore architectural integrity.

• Nonunion: This rare complication most commonly involves displaced anterior process fractures treated nonoperatively with cast immobilization. This is likely caused by the attachment of the bifurcate ligament that tends to produce a displacing force on the anterior fragment with motions of plantar flexion and inversion of the foot.

• Compartment syndrome: Up to 10% of patients with calcaneal fractures have elevated hydrostatic pressure in the foot; half of these patients (5%) will develop claw toes if surgical compartment release is not performed.

  TARSOMETATARSAL (LISFRANC) INJURIES

  Epidemiology

• This is extremely uncommon in children.

• They tend to occur in older children and adolescents (>10 years of age).

  Anatomy (Fig. 52.4)

   

   

   

• The base of the second metatarsal is the “keystone” of an arch that is interconnected by tough,

  plantar ligaments.

• The plantar ligaments tend to be much stronger than the dorsal ligamentous complex.

• The ligamentous connection between the first and second metatarsal bases is weak relative to those between the second through fifth metatarsal bases.

• Lisfranc ligament attaches the base of the second metatarsal to the medial cuneiform.

  Mechanism of Injury

• Direct: This is secondary to a heavy object impacting the dorsum of the foot, causing plantar displacement of the metatarsals with compromise of the intermetatarsal ligaments.

• Indirect: This is more common and results from violent abduction, forced plantar flexion, or twisting of the forefoot.

  • Abduction tends to fracture the recessed base of the second metatarsal, with lateral displacement of the forefoot variably causing a “nutcracker” fracture of the cuboid.

  • Plantar flexion is often accompanied by fractures of the metatarsal shafts, as axial load is

    transmitted proximally.

  • Twisting may result in purely ligamentous injuries.

     

    Clinical Evaluation

• Patients typically present with swelling over the dorsum of the foot with either an inability to ambulate or painful ambulation.

• Deformity is variable, because spontaneous reduction of the ligamentous injury is common.

• Tenderness over the tarsometatarsal joint can usually be elicited; this may be exacerbated by maneuvers that stress the tarsometatarsal articulation.

• Of these injuries, 20% are missed initially.

  Radiographic Evaluation

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

• AP radiograph:

  • The medial border of the second metatarsal should be colinear with the medial border of the middle cuneiform.

  • A fracture of the base of the second metatarsal should alert the examiner to the likelihood of a

    tarsometatarsal dislocation, because often the dislocation will have spontaneously reduced. One may only see a “fleck sign,” indicating an avulsion of the Lisfranc ligament.

  • The combination of a fracture at the base of the second metatarsal with a cuboid fracture indicates severe ligamentous injury, with dislocation of the tarsometatarsal joint.

  • More than 2 to 3 mm of diastasis between the first and second metatarsal bases indicates

    ligamentous compromise.

• Lateral radiograph:

  • Dorsal displacement of the metatarsals indicates ligamentous compromise.

  • Plantar displacement of the medial cuneiform relative to the fifth metatarsal on a weight-bearing lateral view may indicate subtle ligamentous injury.

• Oblique radiograph:

  • The medial border of the fourth metatarsal should be colinear with the medial border of the cuboid.

    Classification

    Quenu and Kuss (Fig. 52.5)

    Type A: Incongruity of the entire tarsometatarsal joint Type B: Partial instability, either medial or lateral Type C: Divergent partial or total instability

     

     

     

    Treatment

    Nonoperative

• Minimally displaced tarsometatarsal dislocations (<2 to 3 mm) may be managed with elevation and a compressive dressing until swelling subsides. This is followed by short leg casting for 5 to 6 weeks until symptomatic improvement. The patient may then be placed in a hard-soled shoe or cast boot until ambulation is tolerated well.

• Displaced dislocations often respond well to closed reduction using general anesthesia.

  • This is typically accomplished with patient supine, finger traps on the toes, and 10 lb of traction.

  • If the reduction is determined to be stable, a short leg cast is placed for 4 to 6 weeks, followed by a hard-soled shoe or cast boot until ambulation is well tolerated.

    Operative

• Surgical management is indicated with displaced dislocations when reduction cannot be achieved or maintained.

• Closed reduction may be attempted as described earlier, with placement of percutaneous Kirschner wires to maintain the reduction.

• In the rare case when closed reduction cannot be obtained, open reduction using a dorsal incision may be performed. Kirschner wires are utilized to maintain reduction; these are typically left protruding through the skin to facilitate removal.

• A short leg cast is placed postoperatively; this is maintained for 4 weeks, at which time the wires and cast may be discontinued and the patient placed in a hard-soled shoe or cast boot until ambulation is well tolerated.

  Complications

• Persistent pain: This may result from unrecognized or untreated injuries to the tarsometatarsal joint caused by ligamentous compromise and residual instability.

• Angular deformity: This may result despite treatment and emphasizes the need for reduction and immobilization by surgical intervention if indicated.

  METATARSALS

  Epidemiology

• This is a very common injury in children and accounts for up to 60% of pediatric foot fractures.

• The metatarsals are involved in only 2% of stress fractures in children; in adults, the metatarsals are involved in 14% of stress fractures.

  Anatomy

• Ossification of the metatarsals is apparent by 2 months in utero.

• The growth plate of the first metatarsal is proximal and the growth plates of the second through fifth metatarsals are distal.

• The metatarsals are interconnected by tough intermetatarsal ligaments at their bases.

• The configuration of the metatarsals in coronal section forms an arch, with the second metatarsal representing the “keystone” of the arch.

• Fractures through the metatarsal neck most frequently result from their relatively small diameter.

• Fractures at the base of the fifth metatarsal must be differentiated from an apophyseal growth center or an os vesalianum, a sesamoid proximal to the insertion of the peroneus brevis. The apophysis is not present before age 8 years and usually unites to the shaft by 12 years in girls and 15 years in boys.

  Mechanism of Injury

• Direct: This results in trauma to the dorsum of the foot, mainly from heavy falling objects.

• Indirect: This is more common and results from axial loading with force transmission through the plantar flexed ankle or by torsional forces as the forefoot is twisted.

• Avulsion at the base of the fifth metatarsal may result from tension at the insertion of the peroneus brevis muscle, the tendinous portion of the abductor digiti minimi, or the insertion of the strong lateral cord of the plantar aponeurosis.

• “Bunk-bed fracture”: This fracture of the proximal first metatarsal is caused by jumping from a bunk bed and landing on the plantar flexed foot.

• Stress fractures may occur with repetitive loading, such as long-distance running.

  Clinical Evaluation

• Patients typically present with swelling, pain, and ecchymosis, and they may be unable to ambulate on the affected foot.

• Minimally displaced fractures may present with minimal swelling and tenderness to palpation.

• A careful neurovascular examination should be performed.

• The presence of compartment syndrome of the foot should be ruled out in cases of dramatic swelling, pain, venous congestion in the toes, or history of a crush mechanism of injury. The interossei and short plantar muscles are contained in closed fascial compartments.

  Radiographic Evaluation

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

• Bone scans may be useful in identifying occult fractures in the appropriate clinical setting or stress fractures with apparently negative plain radiographs.

• With conventional radiographs of the foot, exposure sufficient for penetration of the tarsal bones typically results in overpenetration of the metatarsal bones and phalanges; therefore, when injuries to the forefoot are suspected, optimal exposure of this region may require underpenetration of the hindfoot.

  Classification

  Descriptive

  Location: Metatarsal number, proximal, midshaft, distal

  Pattern: Spiral, transverse, oblique

  Angulation Displacement Comminution Articular involvement

  Treatment

  Nonoperative

• Most fractures of the metatarsals may be treated initially with splinting, followed by a short leg walking cast once swelling subsides. If severe swelling is present, the ankle should be splinted in slight equinus to minimize neurovascular compromise at the ankle. Care must be taken to ensure that circumferential dressings are not constrictive at the ankle, causing further congestion and possible neurovascular compromise.

• Alternatively, in cases of truly nondisplaced fractures with no or minimal swelling, a cast may be placed initially. This is typically maintained for 3 to 6 weeks until radiographic evidence of union.

• Fractures at the base of the fifth metatarsal may be treated with a short leg walking cast for 3 to 6 weeks until radiographic evidence of union. Fractures occurring at the metaphyseal–diaphyseal junction have lower rates of healing and should be treated with a non–weight-bearing short leg cast for 6 weeks; open reduction and intramedullary screw fixation may be considered, especially if a history of pain was present for 3 months or more before injury, which indicates a chronic stress injury.

• Stress fractures of the metatarsal shaft may be treated with a short leg walking cast for 2 weeks, at which time it may be discontinued if tenderness has subsided and walking is painless. Pain from excessive metatarsophalangeal motion may be minimized by the use of a metatarsal bar placed on the sole of the shoe.

  Operative

• If a compartment syndrome is identified, release of all nine fascial compartments of the foot should be performed.

• Unstable fractures may require percutaneous pinning with Kirschner wires for fixation, particularly with fractures of the first and fifth metatarsals. Considerable lateral displacement and dorsal angulation may be accepted in younger patients, because remodeling will occur.

• Open reduction and pinning are indicated when reduction cannot be achieved or maintained. The standard technique includes dorsal exposure, Kirschner wire placement in the distal fragment, fracture reduction, and intramedullary introduction of the wire in a retrograde fashion to achieve fracture fixation.

• Postoperatively, the patient should be placed in a short leg, non–weight-bearing cast for 3 weeks, at which time the pins are removed and the patient is changed to a walking cast for an additional 2 to 4 weeks.

  Complications

• Malunion: This typically does not result in functional disability because remodeling may achieve partial correction. Severe malunion resulting in disability may be treated with osteotomy and pinning.

• Compartment syndrome: This uncommon but devastating complication may result in fibrosis of the interossei and an intrinsic minus foot with claw toes. Clinical suspicion must be high in the appropriate clinical setting; workup should be aggressive and treatment expedient, because the compartments of the foot are small in volume and are bounded by tight fascial structures.

  PHALANGES

  Epidemiology

• Uncommon; the true incidence is unknown because of underreporting.

  Anatomy

• Ossification of the phalanges ranges from 3 months in utero for the distal phalanges of the lesser toes, 4 months in utero for the proximal phalanges, 6 months in utero for the middle phalanges, and up to age 3 years for the secondary ossification centers.

  Mechanism of Injury

• Direct trauma accounts for nearly all these injuries, with force transmission typically on the dorsal aspect from heavy falling objects or axially when an unyielding structure is kicked.

• Indirect mechanisms are uncommon, with rotational forces from twisting responsible for most.

  Clinical Evaluation

• Patients typically present ambulatory but guarding the affected forefoot.

• Ecchymosis, swelling, and tenderness to palpation may be appreciated.

• A neurovascular examination is important, with documentation of digital sensation on the medial and lateral aspects of the toe as well as an assessment of capillary refill.

• The entire toe should be exposed and examined for open fracture or puncture wounds.

• A nail bed injury may be associated with an open fracture of the underlying bone.

  Radiographic Evaluation

• AP, lateral, and oblique films of the foot should be obtained.

• The diagnosis is usually made on the AP or oblique films; lateral radiographs of lesser toe phalanges are usually of limited value.

• Contralateral views may be obtained for comparison.

  Classification

  Descriptive

  Location: Toe number, proximal, middle, distal Pattern: Spiral, transverse, oblique Angulation

  Displacement Comminution Articular involvement

  Treatment

  Nonoperative

• Nonoperative treatment is indicated for almost all pediatric phalangeal fractures unless there is severe articular incongruity or an unstable, displaced fracture of the first proximal phalanx.

• Reduction maneuvers are rarely necessary; severe angulation or displacement may be addressed by simple longitudinal traction.

• External immobilization typically consists of simple buddy taping with gauze between the toes to prevent maceration; a rigid-soled orthosis may provide additional comfort in limiting forefoot motion. This is maintained until the patient is pain free, typically between 2 and 4 weeks (Fig. 52.6).

   

   

   

• Kicking and running sports should be limited for an additional 2 to 3 weeks.

  Operative

• Surgical management is indicated when fracture reduction cannot be achieved or maintained, particularly for displaced or angulated fractures of the first proximal phalanx.

• Relative indications include rotational displacement that cannot be corrected by closed means and severe angular deformities that, if uncorrected, would lead to cock-up toe deformities or an abducted fifth toe.

• Fracture reduction is maintained via retrograde, intramedullary Kirschner wire fixation.

• Nail bed injuries should be repaired. Open reduction may be necessary to remove interposed soft tissue or to achieve adequate articular congruity.

• Postoperative immobilization consists of a rigid-soled orthosis or splint. Kirschner wires are typically removed at 3 weeks.

  Complications

• Malunion uncommonly results in functional significance, usually a consequence of fractures of the first proximal phalanx that may lead to varus or valgus deformity. Cock-up toe deformities and fifth toe abduction may cause cosmetically undesirable results as well as poor shoe fitting or irritation.

PEDIATRIC

ANKLE

FOOT

Fractures

Dislocations