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Journal of the American Academy of Orthopaedic Surgeons 268 Ankle fractures are distal tibial and fibular fractures that occur at or distal to the level of the metaphysis. Defining the cutoff between a pediatric and an adult fracture is some- what arbitrary; the upper age limit of 18 years is often used. Alterna- tively, pediatric fractures may be de- fined as those that occur in individ- uals with open physes regardless of chronologic age. Ankle fractures account for approximately 5% of pediatric fractures and 15% of physeal injuries. 1-4 Such fractures occur twice as frequently in boys. 1-4 Peak incidence is in the age range of 8 to 15 years. The annual incidence of ankle fractures in the pediatric population is approximately 0.1%. Ligamentous injuries in the growing child are unusual. Due to the fact that ligaments are generally stronger than open physes, low- energy trauma (such as an inversion injury) that might result in a ligamentous injury in an adult often results in a physeal fracture in a skeletally immature individual. During the evaluation of children, it is important to correlate physical and radiographic findings, because accessory ossification centers may be misread as fractures. There are two important goals when treating children with ankle fractures: achieving a satisfactory reduction and avoiding physeal arrest so as to minimize the risks of angular deformity, early arthrosis, leg-length inequality, and joint stiffness. The amount of physeal damage incurred at the time of injury is beyond the physician’s control; however, the amount of additional damage can be minimized by limit- ing the number of reduction at- tempts (ideally, only one will be necessary). For fractures crossing the physis, open reduction and internal fixation is frequently used to minimize the risk of physeal arrest as well as to enhance articular congruity. Understanding the anatomy of the foot and ankle aids in the assessment and treatment of these fractures. Anatomy The ankle is a true hinge joint and is stable due to its inherent articular congruity and the surrounding ligamentous structures. Because the dome of the talus is wider anteriorly than posteriorly, there is potentially more translation and rotation when the ankle is plantar-flexed. There- fore, plantar-flexion places the ankle at a higher risk for injury. The medial and lateral collateral ligaments support the ankle. The medial superficial deltoid ligament originates on the distal tibia and inserts onto the talus, the calcaneus, and the navicular. The deep portion of the deltoid ligament inserts onto the talus. There are three lateral ligaments: the anterior talofibular liga- Dr. Kay is Assistant Professor of Orthopaedic Surgery, University of Southern California School of Medicine, Los Angeles, and Attending Surgeon, Childrens Hospital Los Angeles, Los Angeles, Calif. Dr. Matthys is Resident in Orthopaedic Surgery, University of Southern California School of Medicine. Reprint requests: Dr. Kay, Pediatric Ortho- paedics, Childrens Hospital Los Angeles, 4650 Sunset Boulevard, Mailstop 69, Los Angeles, CA 90027. Copyright 2001 by the American Academy of Orthopaedic Surgeons. Abstract Pediatric ankle fractures account for approximately 5% of pediatric fractures and 15% of physeal injuries. The biomechanical differences between mature and immature bones, as well as the differing forces applied to those bones, help explain the differences between adult and pediatric fractures. The potential complications associated with pediatric ankle fractures include those seen with adult fractures (such as posttraumatic arthritis, stiffness, and reflex sympathetic dystrophy) as well as those that result from physeal damage (including leg- length discrepancy, angular deformity, or a combination thereof). The goals of treatment are to achieve and maintain a satisfactory reduction and to avoid physeal arrest. A knowledge of common pediatric ankle fracture patterns and the pitfalls associated with their evaluation and treatment will aid the clinician in the effective management of these injuries. J Am Acad Orthop Surg 2001;9:268-278 Pediatric Ankle Fractures: Evaluation and Treatment Robert M. Kay, MD, and Gary A. Matthys, MD Robert M. Kay, MD, and Gary A. Matthys, MD Vol 9, No 4, July/August 2001 269 ment, the calcaneofibular ligament, and the posterior talofibular ligament. Three structures between the tibia and the fibula further support the ankle mortise: the distal contin- uation of the interosseous mem- brane and the anterior and posterior inferior tibiofibular ligaments. The anterior inferior tibiofibular ligament attaches to the lateral aspect of the distal tibial epiphysis and is important in the pathomechanics of transitional (Tillaux and triplane) fractures. The tibiofibular syndes- mosis is a mobile articulation that allows fibular motion during dorsi- flexion and plantar-flexion. The anatomy of the distal tibial physis has been extensively studied. The initial contour of the physis is transverse. An anteromedial undu- lation appears within the first 2 years, which essentially separates the physis into medial and lateral halves. This is important in understanding the anatomy of certain fracture patterns. Closure of the distal tibial physis progresses from central to medial and then lateral over the course of approximately 18 months. The secondary ossific nucleus of the distal tibial epiphysis generally appears between the ages of 6 and 24 months. The medial malleolus, which begins to ossify between 7 and 8 years of life, forms most commonly from an elongation of the main ossific nucleus of the distal tibia. However, it originates from a separate ossification center, the os subtibiale, in as many as 20% of cases and may be mistaken for a fracture. 5 The distal tibial physis provides 3 to 4 mm of growth annually and contributes approximately 15% to 20% of the length of the lower extremity and 35% to 40% of tibial length. Distal tibial physeal closure is generally completed by age 14 years in girls and age 16 years in boys, although there is minimal longitudinal growth of the distal tibia after age 12 years in girls and age 14 years in boys. The ossific nucleus of the distal fibula typically begins to ossify between 18 and 20 months of life, although ossification may be delayed until age 3 years. The lateral malleolus may also have an accessory ossification center, the os fibulare. Ogden and Lee 6 have shown that the medial and lateral malleolar accessory ossification centers are actually a portion of the cartilage anlage of the malleolus and are sep- arated from the secondary ossification center by epiphyseal cartilage. Classification Pediatric ankle fractures can be classified by using either an anatomic (radiographic) or a mechanism-of- injury scheme. The Salter-Harris classification of physeal fractures (Fig. 1) is the most commonly used anatomic system, because of its sim- plicity and the prognostic signifi- cance of each injury type. Type I and II injuries have lower risks of physeal arrest than injuries classified as types III, IV, and V. Types III and IV generally require open reduction and internal fixation to minimize articular incongruity as well as to decrease the risk of physeal arrest by enhancing the reduction of the physis. The increased risk of growth arrest in type IV injuries stems from the fact that all levels of the physis are disrupted. In type V Figure 1 Salter-Harris classification of fractures. Type I is characterized by physeal separation; type II, by a fracture line that extends transversely through the physis and exits through the metaphysis; type III, by a fracture that traverses the physis and exits through the epiphysis; type IV, by a fracture line that passes through the epiphysis, across the physis, and out the metaphysis. Type V is a crush injury to the physis. Type I Type II Type III Type IV Type V Pediatric Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 270 injuries, the increased risk of growth disturbance is due to the local crush injury to the physis. Type V fractures cannot generally be classified accurately at the time of injury, thus precluding a correct initial prognosis. However, type V fractures account for only 1% of physeal injuries about the ankle. Rang added a sixth type, compris- ing perichondral ring injuries that result from direct open injuries (e.g., those due to lawnmower accidents) or from the trauma of surgical dis- section. 7 In 1950, Lauge-Hansen, on the basis of a series of experimental studies and clinical observations, proposed a classification for ankle fractures in adults. Combining the mechanistic principles of Lauge-Hansen and the Salter-Harris classification, Dias and Tachdjian devised a classification of pediatric ankle fractures using four basic mechanisms: supination- inversion, supination–plantar-flexion, supination–external rotation, and pronation/eversion–external rotation. 7,8 In the description of each mechanism, the first term refers to the position of the foot, and the sec- ond term refers to the direction of the applied force at the time of injury. Two additional fracture patterns were included, the juvenile Tillaux fracture and the triplane fracture. These are termed transitional fractures to indicate their occurrence during the time of physeal closure. Dias subsequently added a ver- tical compression–type fracture, which has the same implications as a Salter-Harris V injury. 7 Such a mechanistic classification scheme theoretically has the advantages of being both precise and useful in selecting the appropriate method to reduce the fracture. The fracture type serves as a guide to the direction of force and the position of the foot at the time of injury. The direction of the force is usually reversed during closed or open reduction. However, the interobserver repro- ducibility of this classification system is low, and it is, therefore, of limited value. Diagnosis A lower-extremity injury must initially be considered in the context of the patient’s overall condition. In the polytrauma patient, concomitant orthopaedic injuries are common, 9 but stabilization of airway, breath- ing, and circulation always takes precedence. A careful neurovascular examination of the extremity should be performed, although a precise motor and sensory examination may be difficult in a frightened child. Cap- illary refill should be assessed. Pulses may not be palpable in the child who has had marked blood loss and has low or low-normal blood pressure. If pulses are not palpable, a Doppler study may aid in the assessment of arterial inflow. If the child cannot cooperate with the examination of light-touch sen- sation distal to the injury, the physician may need to check whether the child responds to painful stimuli, such as needle sticks. Many pediatric ankle injuries occur in patients without injuries to other organ systems. Despite this, a complete history is extremely important. Child abuse and pathologic lesions should be considered if the reported mechanism of injury does not appear to match the fracture type present. Approximately 1% of all children are abused annually, and approximately 2 million reports of child abuse are filed each year in the United States. 10,11 The incidence of physical abuse has been reported as 0.5%, and 1 of every 1,000 abused children will die as a result of the inflicted trauma. 12 Classic radiographic findings, such as corner fractures and multiple fractures in different stages of healing, may be seen in child abuse; however, isolated fractures are seen in 50% of child abuse cases, and the fracture patterns are often unremarkable. 13 Any suspicion of child abuse warrants im- mediate referral to the local child protective services agency. Pathologic fractures may be due to systemic or local disease. A careful patient and family history may alert the orthopaedist to an underly- ing metabolic bone disease. Sys- temic signs and symptoms or pain preceding the fracture should raise the treating physician’s index of suspicion of a pathologic fracture. Bone pain is the presenting com- plaint in approximately 25% of cases of childhood leukemia. 14 Radio- graphs may demonstrate a focal le- sion. Fibrous cortical defects have been reported in 27% of pediatric patients, with the distal tibia being the most common site of pathologic fracture. 15-17 Although lesions mea- suring more than approximately 3.3 cm in diameter or occupying more than 50% of the diameter of a bone appear to carry an increased risk of pathologic fracture, the need for pro- phylactic treatment remains contro- versial. 15,16,18,19 Three radiographic views should be obtained in the evaluation of pediatric ankle injuries. Tillaux fractures and other subtle injuries may be easily missed if only two views are obtained. For some injuries (such as Salter-Harris I fractures), the only radiographic abnormality visible may be soft-tissue swelling adjacent to the physis or slight widening of the physis. Numerous anatomic variations may be present around the ankle, and interpretation of the radiographs must be correlated with the physical examination. Medial accessory ossicles (ossa subtibiale) are found in as many as 20% of patients and lateral ossicles (ossa fibulare) in about 1%. 6 Tenderness in these areas may indicate an acute fracture of the ossicle. Stress radiographs are rarely needed to evaluate pediatric ankle Robert M. Kay, MD, and Gary A. Matthys, MD Vol 9, No 4, July/August 2001 271 injuries. Although some authors have recommended stress views for the diagnosis of nondisplaced Salter-Harris I fractures, they are probably unnecessary and may result in iatrogenic physeal damage. Appropriate indications are to rule out ligamentous injuries and to differentiate an acute fracture from an accessory ossicle. Computed tomography is a useful diagnostic aid, especially for the evaluation of intra-articular fractures, including transitional fractures. If there is unexpected stiffness after treatment, magnetic resonance (MR) imaging may be indicated to look for intra-articular cartilaginous fragments. A thorough evaluation can pro- vide insight into the mechanism of injury and can aid in planning the reduction. Urgent reduction may be required to restore neurovascular function or to relieve skin tenting over a displaced fracture. Treatment of Distal Tibial Fractures Salter-Harris I and II Fractures Salter-Harris I and II fractures have a low incidence of physeal arrest and are generally treated in similar fashion. Type I fractures account for approximately 15% of distal tibial physeal fractures 1-3,20 and generally disrupt the physis through the zone of hypertrophy. Salter-Harris II fractures account for approximately 40% of distal tibial fractures. 1-3,20 In type II fractures, the fracture line extends through the zone of hypertrophy but then exits through the metaphysis, creat- ing a triangular Thurston-Holland fragment. The periosteum is typically torn on the side opposite to the Thurston-Holland fragment and may be interposed in the fracture site. Salter-Harris I and II fractures should be reduced so as to minimize physeal injury. The patient should be well sedated or anesthetized, and reduction should be attempted only once or twice. Closed reduction is used for displaced fractures (Fig. 2). Generally, reduction within a few millimeters is possible, and cast treatment for 4 to 6 weeks results in a successful outcome. Adult cadaver studies have shown that distal-third tibial fractures that heal in 10 de- grees of angulation can markedly decrease the tibiotalar contact area and increase tibiotalar contact pressure 21,22 ; however, comparable data are not available for children. If closed reduction is not successful, open reduction should be performed. Failure of closed reduction is often due to interposed soft tissue, such as periosteum, tendons, and neurovascular structures. After removal of these impediments, the fracture can be reduced and will Figure 2 Plain radiographs of a 13-year-old boy with a Salter-Harris II distal tibial fracture and a Salter-Harris I fibular fracture. A and B, AP and lateral preoperative films obtained in the emergency department. C and D, Films obtained 3 months after a single closed reduction attempt. C D A B Pediatric Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 272 generally be stable. Internal fixation is rarely necessary. If fixation is required for an unstable fracture and the metaphyseal fragment is large and accessible, a 3.5- or 4.0-mm cannulated lag screw parallel to the physis is effective. If the physis must be crossed with hardware, smooth wires should be used. The child should be followed up for signs of healing as well as for evidence of growth arrest after a physeal fracture. Leg-length discrepancy and sagittal- or coronal- plane deformity may be seen clinically. Growth disturbance lines are common radiographic findings after a fractured bone resumes normal longitudinal growth. These lines should be parallel to the physis; if they are absent or not parallel to the physis, growth arrest has occurred. Although complete growth arrest will result in leg-length discrepancy, it may not necessitate intervention if the child is nearing skeletal maturity. In contrast, partial arrest will lead to a progressive angular deformity in addition to the leg-length discrepancy and generally necessi- tates intervention. Medial growth arrest causes varus angulation, leg- length discrepancy, and relative fibular overgrowth with resultant lateral impingement (Fig. 3). Com- plete distal tibial growth arrest does not lead to angular deformity, but relative fibular overgrowth and lateral impingement are potential con- sequences. Salter-Harris III Fractures Salter-Harris III fractures account for approximately 25% of distal tibial fractures. 1-3,20 Because these fractures traverse the physis and exit through the epiphysis, there is often an intra-articular step-off, as well as injury to the subarticular physis. These are commonly seen with medial malleolus fractures as well as with Tillaux fractures. Me- dial malleolus fractures frequently have a large cartilage component, and the fracture fragment is often much larger than the ossified portion that is apparent radiographically. Risks following Salter-Harris III fractures are joint incongruity and growth disturbance. Closed reduction under sedation may be attempted. Open reduction and internal fixation is recommended for all such fractures with more than 2 mm of residual displacement. In one series, 23 growth disturbance developed in only 1 of 20 patients with Salter-Harris III or IV fractures treated with open reduction and internal fixation, but 5 of 9 patients with such fractures who were treated with casting subsequently had radiographic evidence of a bone bridge crossing the physis. If possible, fixation devices should be placed parallel to (and avoiding) the physis. Screw fixation is preferable, but smooth wires may be used. If smooth wires are inserted parallel to the physis, the two wires should not be exactly parallel in all planes, as postoperative displacement may occur after such fixation. Screws or threaded wires should never be placed across an open physis. Smooth pins may cross a physis if necessary for fracture fixation. Pins traversing physes should be removed when the fracture becomes stable, generally within several weeks. Tillaux Fractures Tillaux fractures are Salter- Harris III fractures of the anterolateral portion of the distal tibia, and result from an epiphyseal avulsion at the site of attachment of the anterior inferior tibiofibular ligament (Fig. 4). These fractures are most commonly seen in children nearing skeletal maturity (generally 12 to 14 years old) during the approximately 18-month period during which the distal tibial physis is closing. Tillaux fractures account for 3% to 5% of pediatric ankle fractures. 20,24 The anterolateral location is due to the order of closure of the distal tibial physis (initially centrally, then medially, and finally laterally). Depend- ing on the severity of trauma, there may be an associated distal fibular fracture. The mechanism of injury is typically supination–external rotation. Treatment is directed at obtain- ing and maintaining reduction of the intra-articular surface of the distal tibia. Nondisplaced fractures are immobilized with a long leg cast for 4 weeks. A short leg cast may be used for an additional 2 weeks if physeal tenderness is present on removal of the long leg cast. Com- puted tomographic (CT) scans are used to rule out intra-articular incongruity. Patients with displaced fractures are treated with closed reduction under sedation. The mechanism of injury (supination–external rotation) is reversed, and direct pressure may also be applied to the anterolateral fragment. After reduction, plain Figure 3 AP radiograph of a 14-year-old girl approximately 4 years after a distal tibial fracture complicated by medial growth arrest. There is a 1.7-cm leg-length dispari- ty and a 15-degree varus deformity of the ankle. Growth-disturbance lines (arrow) converge medially due to the medial growth arrest. Robert M. Kay, MD, and Gary A. Matthys, MD Vol 9, No 4, July/August 2001 273 radiographs and CT scans will con- firm the adequacy of reduction. If the intra-articular step-off measures 2 mm or more, reduction and internal fixation is warranted. In the operating room, closed reduction may first be attempted. If an essentially anatomic reduction can be obtained, percutaneous fixation with cannulated screws or wires may be used. However, if such a reduction is not possible, open reduction should be performed through an anterolateral approach to the ankle, so that direct visualization of the fracture fragments and the intra-articular surface can be obtained. Schlesinger and Wedge 25 have described percutaneous manipulation of a displaced Tillaux fracture with a Steinmann pin followed by percutaneous fracture fixation. Fracture fixation may cross the physis in the patient with a Tillaux fracture who is nearing skeletal maturity, as the distal tibial physis is in the process of closing and crossing the physis will not, therefore, result in clinically important growth arrest. If the child has considerable growth remaining, the physis should not be violated with screws. Salter-Harris IV Fractures Salter-Harris IV fractures traverse the metaphysis, physis, and epiphysis to enter the ankle joint, and appear to account for as many as 25% of distal tibial fractures. 1,3 Type IV fractures are seen with triplane fractures and with shearing injuries to the medial malleolus. Patients with nondisplaced fractures should be treated in a non-weight-bearing long leg cast for 4 weeks, which may be followed by a short leg walking cast for another 2 weeks. If there is more than 2 mm of residual displacement, treatment is open reduction and internal fixation to minimize articular incongruity and the risk of physeal bar formation (Fig. 5). The fracture and the articular surface of the distal tibia should be visualized to ensure anatomic reduction. The perichondral ring should not be elevated from the physis, and screw fixation should be parallel to the physis. Fibular fractures accompanying Salter-Harris IV distal tibial fractures are most commonly Salter- Harris I and II injuries. The fibular fracture is usually stable after reduc- Tibia Ligament Fibula A B Figure 4 A, Tillaux fracture. (Adapted with permission from Weber BG, Sussenbach F: Malleolar fractures, in Weber BG, Brunner C, Freuler F [ed]: Treatment of Fractures in Children and Adolescents. New York: Springer-Verlag, 1980.) B, As visualized from below, the Tillaux fragment is seen to be avulsed by the anterior inferior tibiofibular ligament. Figure 5 A, AP radiograph demonstrates a displaced Salter-Harris IV fracture of the distal tibia and a Salter-Harris I fracture of the distal fibula. B, Radiograph obtained 3 months after open reduction and internal fixation of the tibial fracture and closed reduction of the fibular fracture demonstrates good alignment and fixation parallel to the physis. The distal fibular physis has closed, and the distal tibial physis is in the process of closing. A B Pediatric Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 274 tion of the tibial fracture. If the fibula remains unstable after reduction of the tibial fracture, internal fixation is indicated, often with an intra- medullary Kirschner wire. Triplane Fractures Triplane fractures are Salter-Harris IV fractures that challenge the orthopaedist’s three-dimensional per- ception. Triplane fractures have components in the sagittal, coronal, and transverse planes and may be two-, three-, or four-part fractures. They account for 5% to 7% of pediatric ankle fractures. 20,24 These fractures are also considered transitional fractures, but may occur in younger children than Tillaux fractures do. The average age of patients with triplane fractures is approximately 13 years, although they have been reported in children as young as 10. 20,24,26,27 Triplane fractures involve both a metaphyseal fragment posteriorly and an epiphyseal fragment, which is generally lateral. Lateral triplane fractures are more common than medial triplane fractures. Lateral fractures appear similar to Tillaux fractures on anteroposterior (AP) plain radiographs of the ankle, but can be distinguished from them on the basis of evidence of a Salter-Harris II or IV fracture line on the lateral view. Medial triplane fractures are distinguished from lateral triplane fractures radiographically by the more medial location of the epiphyseal and metaphyseal fractures, as well as by the fact that the metaphyseal fracture occurs in the sagittal plane in medial triplane fractures and in the coronal plane in lateral triplane fractures. The epiphyseal fragment is usually connected to the metaphyseal fragment (two-part fracture), although they may be separate fragments. In two-part lateral triplane fractures, one fragment is composed of the anterolateral and posterior portions of the epiphysis joined to the posterior metaphyseal fragment. The other part consists of the anteromedial epiphysis connected to the remainder of the distal tibia (Fig. 6). Three-part lateral fractures differ from two-part lateral fractures in that an additional fracture line separates the anterolateral epiphyseal fragment from the fragment containing the posterior metaphyseal fragment and posterior epiphysis (Fig. 7). The distinction between three- and four-part fractures often can be demonstrated only on CT scans. Four-part fractures are comminuted variants. As with Tillaux fractures, nondisplaced triplane fractures may be treated with immobilization in a long leg cast for 4 weeks, followed by use of a short leg walking cast for an additional 2 weeks. Also as with Tillaux fractures, CT scans are imperative for assessing fracture alignment. Performed with the patient under conscious sedation, closed reduction of two-part triplane fractures (with internal rotation of the distal fragment for lateral triplane fractures and with eversion for medial triplane fractures) may be successful. Such reduction is less commonly Figure 6 A, Two-part lateral triplane fracture. One fragment is composed of the anterolateral and posterior portions of the epiphysis joined to the posterior metaphyseal fragment. The other part consists of the anteromedial epiphysis connected to the remainder of the distal tibia. (Adapted with permission from Jarvis JG: Tibial triplane fractures, in Letts RM [ed]: Management of Pediatric Fractures. Philadelphia: Churchill Livingstone, 1994, p 739.) B, Two-plane medial triplane fracture. (Adapted with permission from Rockwood CA Jr, Wilkins KE, King RE: Fractures in Children. Philadelphia: JB Lippincott, 1984, p 933.) A B Robert M. Kay, MD, and Gary A. Matthys, MD Vol 9, No 4, July/August 2001 275 successful with three- or four-part fractures. Postreduction CT scan- ning is imperative to assess the reduction. Ertl et al 27 have shown that residual intra-articular displacement of 2 mm or more compromises treatment results. Intra-articular displacement of 2 mm or more or displacement at the level of the physis of more than 2 mm in a child with more than 2 years of growth remaining mandates the use of open reduction and internal fixation. Open reduction is generally carried out through an anterolateral approach for lateral fractures or an anteromedial approach for medial fractures in order to visualize the fracture fragments and joint surface. Depending on fracture configura- tion and surgeon preference, either the metaphyseal or the epiphyseal fragment may be fixed initially. Ar- ticular congruity must be restored to maximize patient outcome. Triplane fractures can result in clinically important growth disturbance if they occur in children with at least 2 years of growth remaining. Growth disturbance appears to occur in fewer than 10% of patients after triplane fractures, although Cooper- man et al 26 reported this complication in 3 (21%) of 14 patients. If more than 2 years of growth remains, fixation traversing the physis should be avoided if possible. Cannulated screw systems allow accurate hardware placement and appear to minimize incidental physeal damage. Fixation may be necessary when a high-energy injury results in a comminuted fibular fracture that is likely to shorten (Fig. 8). Fibular fractures proximal to the physis are more common in children nearing skeletal maturity. These fractures are often spiral fractures, which are not stable after reduction of the tibia. The portion of the fibula distal to the fracture site may be reflected distally to enhance expo- sure for tibial fracture reduction. Ertl et al 27 reported marked deterioration in the results of treatment of triplane fractures at a follow-up interval of 3 to 13 years compared with the results at 1.5 to 3 years. This deterioration was seen even in those patients who had undergone accurate open reduction and internal fixation. Salter-Harris V Fractures Salter-Harris V injuries account for 1% of distal tibial physeal injuries and involve a compressive force across the germinal layer of the physis. 1-3,20 Displacement of the epiphysis is rare. If the fracture is accurately identified as a type V injury initially, excision of the damaged portion of the physis and placement of a fat graft may prevent the devel- opment of growth arrest. However, these fractures are generally catego- rized as type V injuries when a patient is noted to have a leg-length discrepancy or angular deformity months or years after a suspected type I physeal injury. The prognosis of this injury is poor due to the sequelae of physeal arrest. With late diagnosis, treatment is directed toward addressing the leg-length discrepancy or angular deformity. Treatment of Distal Fibular Fractures Isolated Fractures Salter-Harris I and II injuries account for approximately 90% of isolated distal fibular fractures, and frequently result from low-energy trauma. An isolated Salter-Harris I fracture can be distinguished from a lateral ankle sprain by the presence of local tenderness over the distal fibular physis rather than over the anterior talofibular, calcaneofibular, and posterior talofibular ligaments. Such isolated injuries generally heal 2 3 2 3 1 1 Talus Figure 7 A, Lateral view of a three-part lateral triplane fracture, which differs from a two- part lateral fracture in that a coronal fracture line separates the anterolateral epiphyseal fragment from the fragment containing the posterior epiphyseal and metaphyseal fragments (1 = anterolateral epiphyseal fragment; 2 = fragment containing the posterior metaphyseal fragment and posterior epiphysis; 3 = tibia). B, View from below shows relationship of the fracture components. (Adapted with permission from Marmor L: An unusual fracture of the tibial epiphysis. Clin Orthop 1970;73:132-135.) A B Pediatric Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 276 well within 3 weeks in a short leg walking cast. Salter-Harris III and IV injuries are rare and must be distinguished from an accessory ossification center (os fibulare). Re- duction is rarely necessary, but may be required for the rare distal fibular Salter-Harris III or IV fracture with marked residual displacement. Avulsion of accessory ossification centers of the distal fibula may be symptomatic. Ogden and Lee 6 noted that these avulsion fractures are analogous to Salter-Harris II fractures if the accessory ossification center is considered an epiphysis. They recommended immobilization in a short leg walking cast for 2 to 3 weeks. They also reported that non- operative treatment sometimes fails and surgical treatment becomes necessary, although this seems to be quite rare. Fractures Combined With Distal Tibial Fractures Fibular fractures seen in conjunction with distal tibial fractures are routinely reduced with reduction of the tibial fracture. These fibular fractures tend to be stable after reduction and rarely require fixation in the skeletally immature individual. Fixation may be indicated for the child nearing skeletal maturity with a severely A B D E C Figure 8 A and B, AP and lateral radiographs of a 90-kg 14-year-old boy reveal a two-part lateral triplane fracture and a comminuted distal fibular fracture. Arrows indicate the apparent gap between the fracture fragments. C, CT scan shows the marked external rotation of the lateral portion of the distal tibia, the marked fracture displacement, and the mild comminu- tion of the medial tibia. D and E, Radio- graphs obtained 1 year after operative treatment demonstrate healed fractures in a satisfactory position and closure of the distal tibial and distal fibular physes. Robert M. Kay, MD, and Gary A. Matthys, MD Vol 9, No 4, July/August 2001 277 comminuted fracture at risk for shortening. Complications of Ankle Fractures Growth Arrest Growth arrest is most common after distal tibial Salter-Harris III and IV fractures, and often leads to both a leg-length discrepancy and an angular deformity of the ankle. Leg- length discrepancy is related to the child’s age at the time of fracture and usually is between 1 and 2 cm. 23,28 In one series, growth disturbance developed in only 1 (5%) of 20 patients with Salter-Harris III or IV fractures treated with accurate open reduction and internal fixation, in contrast to 5 (56%) of 9 patients with similar fractures treated with closed reduction. 23 If the growth arrest is detected before considerable angular deformity develops, the main issue is the ultimate leg-length discrepancy predicted. If considerable angular deformity is already present at the time the physeal arrest is detected, an osteotomy is the only possible solution to correct the me- chanical axis. The amount of angular deformity that is acceptable has not been established, although angulation in distal tibial fractures has been shown to markedly increase contact pressure in the ankle joint in adult cadaver studies. 21,22 For children nearing skeletal maturity, epiphysiodesis of the part of the physis that remains open may be all that is necessary if no angular deformity is present. For example, because the distal tibia grows only 3 to 4 mm annually as the child nears skeletal maturity, a child with 2 years of growth remaining will lose less than 1 cm of leg length if a complete arrest occurs. Epiphysiodesis of the distal fibula should be considered to prevent fibular overgrowth and lateral impingement. In younger children, physeal bar resection may be considered if the bar encom- passes less than 50% of the physis as delineated on MR images. Osteoarthritis Osteoarthritis may result from chondral damage at the time of injury or articular incongruity at the time of fracture healing. In a long- term study an average of 27 years after injury, 12% of all 71 patients with physeal ankle fractures had radiographic evidence of osteoarthritis, compared with 29% of patients with a Salter-Harris III or IV fracture. 28 In the same study, the late results correlated most strongly with the initial fracture displacement and with the residual displacement after reduction. In a study of triplane fractures, Ertl et al 27 concluded that anatomic reduction of intra-articular fractures may reduce the incidence of late arthritis. Ankle Stiffness Posttraumatic ankle stiffness is likely due to a combination of injuries to both the soft tissues and the osseous structures. Caterini et al 28 reported this complication in 4 (6%) of 71 patients at long-term follow- up and found that it correlated with radiographic evidence of osteoarthritis in 3 of the 4 patients with ankle stiffness. Physical therapy should be used to treat all patients with severe injuries as well as to treat those patients with marked residual ankle stiffness 1 month after cast removal. Reflex Sympathetic Dystrophy As in adults, reflex sympathetic dystrophy (RSD) in children is characterized by pain out of proportion to an injury in conjunction with signs of autonomic dysfunction of the injured extremity. The condition is more common in lower-extremity injuries and often follows trivial trauma. In the largest reported series of RSD in children, the authors noted a 1-year delay from the onset of symptoms to the diagnosis. 29 In that series, 84% of the patients were girls. The most important aspect of treatment of RSD is prompt recog- nition. Potential components of treatment include physical therapy, psychological counseling, drug therapy, and sympathetic blockade. Wilder et al 29 reported that, at a me- dian follow-up interval of 3 years, 38 (54%) of 70 patients with RSD had persistent symptoms despite aggressive treatment. Summary Pediatric ankle fractures are common injuries. Appropriate treatment is guided by the accurate assessment of the injury itself, as well as its potential ramifications. The goals of treatment are a satisfactory reduction and the avoidance of growth disturbance. Closed reduction of physeal injuries should be carried out a minimal number of times (preferably once) and should be done only in well-sedated or anesthetized patients. It is important to recognize that even injuries that appear benign initially may have poor long-term results. Closed treatment and casting of Salter-Harris I and II distal tibial fractures generally yield good results. Salter-Harris III and IV distal tibial fractures have high incidences of articular incongruity, physeal arrest, and late arthritis if treated by closed means, and require open reduction and internal fixation if there is more than 2 mm of residual displacement. Computed tomographic scans are more useful in the evaluation of residual displacement than plain radiographs, which are often out of plane with the fracture. Salter-Harris V injuries account for only 1% of distal tibial fractures, and are often recognized only retro- spectively. Growth disturbance lines should be carefully monitored,

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