Introduction
Fractures and injuries about the foot and ankle in children are common and can have an important functional impact. Foot and toe fractures are among the top 10 pediatric orthopaedic injuries requiring hospitalization, and physeal injuries about the ankle are the second most common growth plate fracture. A pain-free and deformity-free foot and ankle after injury allow a child the freedom to run, play, explore the environment, and satisfy unlimited personal curiosities. If a residual deformity lingers after injury, the child limps, which causes distress for the parents, who may feel that they did not do enough to prevent their child’s problem. The child is teased and taunted by peers and may have an arthritic problem that causes pain and leads to unfulfilled wishes—whether they be simply to walk through a meadow and smell the flowers or to be a great athlete. Our collected thoughts and those of our referenced colleagues are intended to guide the reader to a safe resolution of foot and ankle injuries in children.
The Ankle
Relevant Anatomy
The ankle joint is a true mortise joint, or a modified hinge joint, that consists of three bones: the tibia, fibula, and talus. The joint essentially moves in only one plane, from plantar flexion to dorsiflexion. The lateral malleolus allows minimal rotation to accommodate the changing width of the talar dome. The talar dome is broader anteriorly than posteriorly and, as a result, allows less rotation when the foot is in dorsiflexion than when it is in plantar flexion. The anatomic relationships and limited joint motion render the distal fibular epiphysis particularly vulnerable to crushing and twisting injuries ( Fig. 17-1 ).
The ligaments about the ankle are attached to the epiphyses ( Fig. 17-2 ). The deltoid ligament arises from the tip of the medial malleolus distal to the growth plate; it consists of two sets of fibers—superficial and deep. The superficial fibers originate from the anterior portion of the medial malleolus (anterior colliculus) and span out to attach to the calcaneus, navicular, and talus. The deep portion of the deltoid ligament originates from the posterior portion of the medial malleolus (posterior colliculus and intercollicular groove) and inserts into the medial surface of the talus. On the lateral aspect of the ankle, support is provided by three separate ligaments. Their tension and spatial orientation change according to the position of the ankle joint: plantar flexion, neutral, or dorsiflexion. These ligaments have their origin on the fibula distal to the physis. The anterior talofibular ligament runs anteriorly and medially from the anterior margin of the lateral malleolus to the talus anteriorly. The posterior talofibular ligament runs horizontally from the sulcus on the back of the lateral malleolus to the posterior aspect of the talus. The calcaneofibular ligament extends downward and slightly posterior from the tip of the lateral malleolus to a tubercle on the lateral aspect of the calcaneus; it is in close relationship to the peroneal tendons and their sheath. The growth plate is more likely than the ligaments to fail during the years of skeletal development because of tensile weakness in the growth plate. The tibiofibular syndesmosis consists of four ligaments—the anterior and posterior inferior tibiofibular ligaments, the interosseous ligament, and the anterior transverse ligament—in addition to the interosseous membrane. The anterior tibiofibular ligament runs downward between the anterior margin of the tibia and fibula; its origin in the fibula is also distal to the growth plate. The tibiofibular syndesmosis is rarely injured in children because the ligament is stronger than the growth plates, which tend to give more easily. In an adolescent in whom the growth plate has closed, disruption of the tibiofibular syndesmosis can occur.
The distal tibial physis begins to close about 18 months before complete cessation of tibial growth, first closing in its midportion, then medially, and finally laterally. Longitudinal growth of the distal tibial epiphysis ceases at about 12 years of age in girls and 13 years in boys. The fusion process does not occur uniformly but is instead asymmetric ( Fig. 17-3 ). Fusion begins in the area of the tibial “hump,” which is located centrally and is seen on the anteroposterior (AP) view as a small bump over the area of the medial edge of the talus. As fusion progresses, the medial part of the plate closes and then progresses posteriorly; finally, the anterolateral part of the plate fuses. The average time to fusion is 18 months. The fused part of the epiphyseal plate is no longer weak and prone to fracture but becomes an area of relative strength. The irregular fusion pattern and the resulting areas of relative strength and weakness are responsible for the unusual transitional fracture patterns, specifically, juvenile Tillaux and triplane fractures.
Accessory ossicles of the malleoli are common in skeletally immature individuals. They usually appear between the ages of 7 and 10 years and eventually fuse with the secondary ossification center of the malleolus at skeletal maturity. The lateral ossicle has been termed the os subfibulare. Most of these ossification variations are identified only fortuitously, when radiographs are taken to evaluate an injury to the ankle or foot. They may be confused with a sleeve fracture–avulsion of the medial or lateral malleolus. If the patient is symptomatic and the presence of a lesion is uncertain, a positive technetium bone scan or magnetic resonance image (MRI) may support a diagnosis of injury.
Incidence and Mechanism of Injury
Injuries are commonly caused by indirect violence, in which the fixed foot is forced into eversion–inversion, plantar flexion, external rotation, or dorsiflexion. Fractures may also be sustained by direct violence: the history is then usually an automobile accident, a fall from a height, or participation in contact sports. Injuries to the lower part of the leg and foot are more common in boys and usually occur between the ages of 10 and 15 years. Those about the ankle constitute 10% to 25% of all physeal injuries. The distal tibial epiphysis is the second most common site of epiphyseal fracture in children, after the distal end of the radius. The bone of a child is more capable of elastic and plastic deformation than adult bone is. Ligamentous injuries have traditionally been considered to be rare because the ligaments are stronger than the physes, but a recent prospective cohort study has shown that a combination of lateral ligament and bony injury coexists in 90% of suspected Salter–Harris type I fractures of the distal fibula. These forces are transmitted to the medial part of the tibia by the ligamentous pull of the deltoid ligaments. Laterally, forces are transmitted by the anterior and posterior tibiofibular ligaments, the anterior and posterior talofibular ligaments, and the calcaneofibular ligaments. The tendency for physeal compression during adduction injury is also greater. With an adduction injury, medial migration of the talus is usually blocked by the medial malleolus, and the medial malleolus is subsequently fractured.
Consequences of Injury
The prognosis for injuries to the foot and ankle involves several criteria. The skeletal maturity of the patient determines the resulting bone, ligament, and/or growth plate injury. At different skeletal ages, the same mechanical twisting, torsional force, or related trauma to the foot and leg causes different injuries. Children are more prone to epiphyseal injuries, which, of course, are subject to more complications than are shaft or metaphyseal injuries. The more severe the injury (e.g., open fracture, grossly contaminated, and comminuted with or without soft tissue crushing), the greater the possibility of secondary devitalization with consequent delayed union, nonunion, pseudarthrosis, or osteomyelitis. The adequacy of reduction directly influences the rate of union; the more bony contact, the less healing time required. In addition, anatomic reduction is especially important for growth plate fractures because anatomic alignment reduces the incidence of angular deformity and shortening secondary to growth arrest, as well as degenerative arthritis secondary to persistent joint incongruity (step-off) and instability. The prognosis after fractures involving the distal end of the tibia in children depends on the skeletal maturity of the patient, the severity of the injury, the fracture type, the degrees of comminution and displacement of the fracture, and the adequacy of reduction.
Radiologic Evaluation
In recent years clinical prediction rules that focus on eliciting bony tenderness have led to refinement in the use of plain film radiography of the pediatric ankle; that is, the need for radiography has been reduced by approximately 25% without missing any fractures. Although some institutional variation has been reported, multiple studies have now shown that both doctors and nurses can effectively apply such decision rules (also referred to as ankle rules) in ambulatory care settings. Standard three-view (i.e., AP, lateral, and mortise) radiographs have recently been reaffirmed as the initial diagnostic views of choice. Consideration may be given to more selective use of radiographs during follow-up of known injuries.
AP and lateral views of the injured area should always be taken. If swelling is present and no injury can be seen, a mortise view is recommended. One should assess the soft tissue very carefully. The normal fat stripe surrounding a bone may be thickened after a nondisplaced fracture. In addition, joint effusion after nondisplaced articular fractures may result in a positive fat pad, or synovial sign, especially in the anterior aspect of the ankle over the talar neck or posteriorly, with displacement of the Achilles tendon fat stripe ( Fig. 17-4 ). Computed tomography (CT) is recommended for imaging articular fractures when plain radiographs show displacement of greater than 2 mm. The use of CT has been shown to significantly improve the accuracy of screw placement for such fractures. Paradoxically a European survey of surgeons revealed that only 38% used CT routinely in their management of triplane fractures. This may simply reflect a high level of confidence in allowing orthopaedic plain film interpretation to drive surgical decision making. In an adult cadaver Tillaux fracture setting, such plain film–driven decision making has been shown to be accurate to within 1 mm 75% of the time, whereas CT achieved this goal only 50% of the time. It must also be remembered that, in contrast to plain film radiography, CT exposes the child to even more substantial amounts of radiation that are often several orders of magnitude greater.
Even though intraoperative fluoroscopy is excellent for evaluating reduction in the operating room, the authors recommend permanent plain radiographs after reduction and before waking the patient. This can be considered the hard copy “report card.” The worst time to discover failure of anatomic reduction and stabilization is when one is examining radiographs taken in the recovery room or while the patient is being transferred to the floor. After treatment, if the patient has any stiffness or fails to achieve adequate range of motion, a contrast CT scan or MRI is indicated to exclude any intraarticular cartilaginous (silent) fragments.
When fractures about the ankle in children are monitored, it is extremely important to observe the Park–Harris growth arrest lines. These lines represent transient calcification of physeal cartilage during injury repair and are an excellent marker for observing growth after injury. The lines are parallel to the physis if growth is occurring normally ( Fig. 17-5 ). In children with physeal damage, the line may be tented or angular. Special attention to this phenomenon is indicated in Salter–Harris types III and IV injuries to the medial malleolus ( Fig. 17-6 ).
Classification
In 1978, Dias and Tachdjian introduced a classification of children’s fractures that incorporated the concepts of Lauge–Hansen. To classify the fracture properly, radiographs are necessary; AP, lateral, and oblique views must be taken. In their classification ( Table 17-1 ), the first part of the type name describes the position of the foot at the moment of trauma, and the second notes the abnormal force applied to the ankle joint: supination–inversion, pronation–eversion/external rotation, supination–plantar flexion, or supination–external rotation ( Fig. 17-7 ).
| TYPE | GRADE | POSITION OF FOOT | INJURING FORCE | PATTERN OF FRACTURE | COMMENT |
|---|---|---|---|---|---|
| Supination–inversion | 1 | Supinated | Inversion | Usually Salter–Harris type I or II fracture–separation of the distal fibular physis Occasionally rupture of the lateral ligament or fracture of the tip of the lateral malleolus | Displacement minimal and almost always medial |
| 2 | Supinated | Inversion | Usually Salter–Harris type III or IV fracture of the medial part of the tibial epiphysis Rarely Salter–Harris type I or II fracture with medial displacement of the entire tibial epiphysis | Caution: Risk of up to 50% growth arrest without surgery, 2% with surgery | |
| Supination–plantar flexion | 1 | Supinated | Plantar flexion | Commonly Salter–Harris type II fracture of the tibial epiphysis Rarely Salter–Harris type I fracture of the tibial physis No associated fracture of the fibula Metaphyseal fragment and displacement posterior Fracture line is best seen on a lateral radiograph | Prognosis good Caution: Do not damage growth plate by forced manipulation Posterior displacement will remodel |
| Supination-external rotation | 1 | Supinated | External rotation | Salter–Harris type II fracture of the distal tibial epiphysis with long spiral fracture of the distal tibia starting laterally at distal tibial growth plate | Up to 35% risk of distal tibial growth arrest |
| 2 | Supinated | External rotation | Grade 1 plus spiral fracture of the distal fibular shaft | ||
| Pronation–eversion/lateral rotation | 1 | Pronated | Eversion–lateral rotation | Salter–Harris type II fracture of the distal tibial epiphysis Metaphyseal fragment lateral or posterolateral Displacement lateral or posterolateral | Greater than 50% risk of distal tibial growth arrest |
| 2 | Fibular fracture short, oblique, 4–7 cm from tip of the lateral malleolus | ||||
| Miscellaneous | |||||
| Adolescent Tillaux | — | Neutral? | Lateral rotation | Salter–Harris type III fracture of the lateral part of the distal tibial epiphysis Should not be any metaphyseal fragment Displacement anterolateral | Medial part of the distal tibial physis closed |
| Triplane, three fragments | — | ? | Lateral rotation | Fracture in three planes—coronal, sagittal, and transverse Combination of Salter–Harris types II and III Fracture produces three fragments | Medial part of the distal tibial physis open |
| Triplane, two fragments | — | ? | Lateral rotation | Fracture in three planes—coronal, sagittal, and transverse Combination of Salter–Harris types II and III | Medial part of the distal tibial physis usually closed |
| Comminuted fracture of the distal end of the tibia | — | ? | Crushing injuries Direct violence | Comminuted fracture involving the distal tibial epiphysis Physis often damaged Fibula fracture at various levels | Poor prognosis |
Spiegel and colleagues ( Fig. 17-8 ) monitored 184 of a series of 237 fractures of the distal end of the tibia, fibula, or both for an average of 28 months after injury. Using the Salter–Harris classification, they differentiated three groups according to their risk of shortening of the leg, angular deformity of the bone, or incongruity of the joint. The low-risk group consisted of 89 patients, 6.7% of whom had complications; this group included all type I and type II fibular fractures, all type I tibial fractures, type III and type IV tibial fractures with less than 2 mm of displacement, and epiphyseal avulsion injuries. The high-risk group consisted of 28 patients, 32% of whom had complications; this group included type III and type IV tibial fractures with 2 mm or more of displacement, juvenile Tillaux fractures, triplane fractures, and comminuted tibial epiphyseal fractures (type V). The unpredictable group consisted of 66 patients, 16.7% of whom had complications; only type II tibial fractures were included. The incidence and types of complications were correlated with the type of fracture (Carothers and Crenshaw classification), the severity of displacement or comminution, and the adequacy of reduction.
Despite their complexity, ankle fractures in children can be roughly divided into avulsion and epiphyseal fractures. Adequately reduced avulsion fractures can be expected to heal well; epiphyseal fractures, however, may give rise to late complications. Vahvanen and Alto proposed that classification of ankle fractures in children be based on radiographic findings, primarily with respect to epiphyseal lesions, and on a simple grouping with regard to risk for clinical purposes: group I, low-risk avulsion fractures and epiphyseal separations; and group II, high-risk fractures through the epiphyseal plate. The authors agree completely with this simplistic concept. Most avulsion fractures in children heal very well and have few complications; those that involve the epiphyseal plate tend to lead to either failure of continued growth because of damage to the endochondral ossification sequence or the potential for arthritis from interfragmentary gaps or articular step-offs greater than 3 mm.
Indications for Surgical Treatment
Primary indications for surgical treatment include open fractures, inability to obtain or maintain an adequate closed reduction, displaced articular fractures, displaced physeal fractures, or any evidence of massive soft tissue injury.
Surgical Technique
Every effort should be made to reduce the fracture anatomically and obtain accurate alignment of the physis and articular surface. If anatomic reduction can be achieved by closed manipulation, strong consideration should be given to stabilizing the fracture with any of the multiple modern cannulated screw systems, other specially designed fracture fixation sets, or Kirschner wires. The keys are quite clearly anatomic reduction and stable internal fixation. Indirect reduction as an adjunct to closed manipulation is extremely effective in treating children’s ankle fractures. It is most effective when the fracture is fresh or before an interfragmentary clot has formed. The authors have performed indirect reduction of medial malleolar and Tillaux fractures by using a Steinmann pin through the distal fragment as a levering device, or “joystick,” to anatomically align the fragment; direct manual compression is then applied, and the pin is continued across the fracture site. Once anatomic reduction and alignment are achieved, one can either use a plaster-of-Paris cast or place a cannulated screw over the pin to maintain stability. Over the past 35 years, the senior author (A.H.C.) has preferred this indirect reduction technique over open reduction whenever possible.
If one has to perform open reduction, adequate exposure of the physis, articular surfaces, or both is mandatory. Every effort should be made to diminish the amount of soft tissue dissection by placing the incision over the area of the fracture gap. One can usually see elevation of the periosteum at the level of the fracture, and little additional dissection is necessary. By irrigating the wound, removing any clots, and extracting any bony debris by curettage, it is usually possible to realign the fracture anatomically. If anatomic reduction is prevented by a distal metaphyseal fragment, such as that found with a Salter–Harris type IV fracture, it is possible to remove the metaphyseal fragment and obtain anatomic alignment of the epiphysis without damaging the physeal line. On occasion, a periosteal flap may prevent anatomic reduction. Once anatomic alignment has been achieved, one should pin the epiphysis to the intact portion of the epiphysis and, if it was not necessary to remove the metaphyseal fragment, the metaphysis to the metaphysis. The authors strongly recommend against placing a pin obliquely across the physis in a growing child. Unless evidence of closure of the middle of the physis is seen, the authors would not place an oblique pin across the fracture site, similar to the technique used in adults for medial malleolar fractures.
It is strongly recommended that most displaced injuries be treated under general anesthesia so that the child is completely relaxed and adequate reduction can be achieved. Because of projectional distortion, the image intensifier film may fail to show the same degree of clarity as plain films. The authors therefore firmly recommend three-view plain radiographs as a “report card” for all reduced, displaced physeal and articular fractures before applying the cast and leaving the operating room.
Comments on Specific Fracture Patterns
Introduction
The Dias–Tachdjian pediatric ankle fracture classification has stood the test of time as a useful tool for categorizing and understanding these injuries. The authors would estimate that this classification system easily accounts for more than 90% of the nontransitional ankle fractures encountered in children. Outcome studies have also indicated prognostic differences among the various categories and the ability of surgical intervention to improve treatment results. Universal agreement does not exist because some authors have emphasized that the risk of growth arrest may simply be linked to higher energy injuries. Other authors have also voiced skepticism about the ability of surgery to reduce the overall risk of growth arrest.
Supination–Inversion
The supination–inversion mechanism is considered to be the most common of the pediatric ankle fracture patterns. This makes immediate sense because the first stage of this injury pattern is a Salter–Harris I or II fracture of the distal fibula (usually nondisplaced), a ubiquitous fracture in pediatric orthopaedic trauma clinics. At times this injury may amount to a physis-opathy or physis-itis (which amounts to a stress fracture) of the distal fibular growth plate. More commonly, the radiographic appearance of the osseous distal fibula is normal, and pain, tenderness, and swelling (“goose egg”) on clinical examination make the diagnosis.
The second stage of this injury involves a Salter–Harris type III or IV injury of the medial malleolus. This typically attracts much attention, but it must be remembered that the distal fibula fractures first and the medial malleolus fractures second. After separation of the distal fibular epiphysis, the inversion–adduction force of the talus striking the medial malleolus produces the resultant fracture pattern. Radiographs typically show the fracture to involve less than one third of the mediolateral distance across the epiphysis because the fracture line extends vertically to the physis and exits medially through the physis ( Fig. 17-9 ). Determining the precise extent of displacement in these fractures is crucial because a significant gap may lead to growth arrest. As the fracture unites, the ossification process above and below the physis may span the growth plate and form a bony bridge anchored in the metaphyseal and epiphyseal calluses. The width and, in turn, the strength of that bridge depend on the size of the residual interfragmentary gap. A thin, weak bridge may have no adverse effect on growth because disruption of the bridge requires substantial force.
As mentioned earlier, the medial malleolar fracture fragment (either a Salter–Harris type III or IV) usually attracts the most attention, and most of the following discussion focuses on it. However, it must be remembered that this medial fragment does not occur without the distal fibular growth plate fracturing first, and in a minority of cases the fibula may merit formal reduction and smooth Kirschner wire fixation. In the past when these fractures were treated via closed reduction and cast immobilization, the rate of growth arrest (particularly of the medial malleolar growth region) may have often exceeded 50%. However, with current concepts of anatomic reduction and modern stable internal fixation, these growth-related complications may be seen in as few as 2% of patients. Thus the precedent for surgical treatment is rather strong in this fracture pattern.
For a medial malleolar fracture, either indirect reduction (closed reduction) and internal fixation or open reduction and internal fixation under general anesthesia are performed if the displacement is greater than 2 mm after reduction. A percutaneous cannulated interfragmentary screw can be inserted quite neatly and allows excellent control if closed reduction to within 2 mm is achieved. A washer can be very important in this relatively soft regional bone because it acts as a one-hole plate to distribute forces generated by the screw head, thus allowing the possibility of greater interfragmentary compression. If logistically possible, percutaneous procedures are less traumatic and result in less operative exposure with less potential for vascular compromise and infection. Additionally, the reduction is adequately stabilized. Most of these fractures have remarkably small Thurston–Holland (metaphyseal spike) fragments that do not lend themselves to fracture fixation. Thus epiphysis-to-epiphysis fixation is the rule (with care taken not to leave threads across the fracture line); however, in rare cases, metaphysis-to-metaphysis fixation may be possible. Every effort should be made to avoid placing the screw from the epiphysis across the physis into the metaphysis unless the physis is impressively thin and closing. At times, the metaphyseal fragment may be warped or fragmented, it may be necessary to discard it to ensure anatomic reduction of the epiphysis. Removing the fragment also prevents the formation of a bony bridge ( Fig. 17-10 ).
After reduction and stable internal fixation of the medial malleolar fragment and after appropriate attention to the distal fibular fracture, non–weight-bearing cast immobilization is added. The screw should be removed slightly less than 1 year after treatment. If the screw is not removed within an appropriate time frame, exuberant callus may encase it. Removing such a screw late may then subject the extremity to more trauma than simply leaving it in place. The authors have no experience with the use of bioabsorbable implants for the management of these fractures. Certainly, in selected cases, closed reduction and cast immobilization of this injury may be successful when the fracture is not displaced and anatomic reduction is achieved and maintained ( Fig. 17-11 ). The only mandatory reason for removal of asymptomatic implants is if the child is expected to pursue military service: the presence of such metallic implants has been considered by some military recruiters to be disqualifying.
Supination–External Rotation
This pediatric ankle injury pattern has been recognized for quite some time. The supination–external rotation mechanism is considered to first result in a physeal fracture of the distal tibia that typically has a rather large and medially based (to posteromedially based) Thurston–Holland fragment. Continuation of these injury forces results in a nonphyseal fracture of the distal fibula. This pediatric injury pattern mimics the adult pattern of the same name in that, when the fibula is involved, its distal diaphyseal fracture line extends along an anterodistal-to-posteroproximal line ( Fig. 17-12 ).
The displacement of the supination–external rotation injury is typically not subtle. The ankle is swollen and painful, and the deformity is obvious. The apex of the deformity is usually anterolateral, and the previously mentioned oblique-to-spiral-oblique fibular fracture is virtually always present. Interposed periphyseal periosteum is certainly a possibility but has a somewhat lower likelihood simply because of the large size of the associated Thurston–Holland fragment. Anatomic reduction is the goal, with axial forces being applied via manual calcaneal traction and a variable amount of internal rotation followed by dorsiflexion. Postreduction images must be critically evaluated with respect to restoration of overall anatomic ankle alignment, significant residual physeal widening, and persistent fibular displacement.
The treating orthopaedic surgeon must decide how much displacement is acceptable in these supination–external rotation injuries. These extraarticular fractures are very different from the displaced intraarticular fractures of the previously discussed supination–inversion category. Nonetheless, concern exists about premature distal tibial growth arrest due to residual physeal displacement and abnormal joint forces secondary to fibular malunion. The amount of displacement that may trigger surgical intervention may be as little as 3 mm of physeal gapping and 2 mm or more of fibular displacement. Literature documenting the remodeling potential of these Salter–Harris type II fractures is scarce. It has been suggested in the literature that a premature physeal closure rate for this injury pattern could be as high as 35%. Others have documented the abnormal joint forces after fibular malunion. Thus anatomic reduction and stable internal fixation is becoming more common than in the past. The large Thurston–Holland fragment associated with these injuries lends itself to stable internal fixation with one or even two cannulated screws (again a washer is suggested because of the relatively soft metaphyseal bone). The fibular fracture is amenable to standard open reduction, lag screw placement, and application of a physeal-sparing one-third tubular neutralization plate.
Pronation–External Rotation
The pronation–external rotation fracture pattern was originally described by Dias and Tachdjian as a single stage injury, almost as if the respective tibial and fibular injuries occurred at the same time. However, it is commonly taught that this pediatric ankle fracture involves fracture of the distal tibial growth plate first (frequently with a rather small but easily seen laterally based Thurston–Holland fragment) followed by a rather transverse and substantially higher fracture of the fibular diaphysis ( Fig. 17-13 ). Once again, this fibular fracture more closely mimics the fibular fracture associated with the adult supination–external rotation ankle fracture pattern. Displacement of this pediatric ankle fracture is almost never subtle in that the translation (lateral) and angulation (apex medial) of the distal tibial epiphyseal fragment is substantial; angulation (apex medial) of the fibular shaft fracture is equally impressive. One of the authors (C.T.M.) is fond of saying that the same radiograph is seen over and over but different patients’ names are on it.
Carothers and Crenshaw expressed their greatest concern for growth arrest after these pronation–external rotation injuries. These concerns have been echoed by contemporary authors as premature physeal closure rates that exceed 50% have been reported. A high-energy mechanism of injury has also been implicated in growth arrest of such ankle fractures. Such concerns led to Carothers and Crenshaw’s reduction of these injuries under anesthesia and their selective use of internal fixation (even in 1955). Modern fixation techniques most frequently involve standard plate fixation of the fibular fracture and smooth Kirschner wire fixation of the tibial fracture because the Thurston–Holland fragment usually does not represent a reliable screw fixation point.
Supination–Plantar Flexion
This is the only mechanism that is considered to result in a displaced growth plate fracture of the distal tibia without any associated fibular fracture. The tibial Thurston–Holland fragment is variable in size but is predominantly posterior in location. It is clear from multiple published series that this plantar flexion injury is the least common of the pediatric ankle injury patterns. Displacement is also typically subtle, and the lateral radiograph is the most likely to show mild widening of the tibial physis ( Fig. 17-14 ). No special studies are required for this injury because the diagnosis is fairly straightforward.
At least three cases of rotational displacement of the lower tibial epiphysis secondary to trauma have been reported. The injury is of the supination–plantar flexion variety with a Salter–Harris type I distal tibial fracture and an intact fibula. In this rare injury to the distal tibial growth plate, the distal tibial epiphysis undergoes true rotational displacement with posterior displacement of the fibula but without fracture of the fibula. The fibula in these cases appears to be plastic enough to twist without breaking. Reduction is achieved with an audible click, probably caused by the fibula snapping back into the metaphyseal portion of the incisura fibularis and having retained its normal relationship and attachments to the displaced tibial epiphysis. No permanent damage to the growth plate was noted with these injuries.
Despite displacement that usually ranges from subtle to meeting virtually all orthopaedist’s definition of undisplaced, growth arrest after the supination–plantar flexion mechanism is not rare. Unlike the other ankle fracture mechanisms already discussed, contemporary literature does not offer a specific estimate of the rate of this growth disturbance. Therefore the treating orthopaedic surgeon’s decision making must be guided by an appreciation of the amount of physeal displacement and estimation of the amount of remaining growth. Clearly, there is little need for reduction of mild residual physeal displacement aimed at decreasing the likelihood of growth arrest in a patient with very little remaining growth. If it is determined that significant growth remains and the surgeon opts for surgical treatment, care must be taken to extract any interposed periosteum because it is fairly common in this injury pattern. After anatomic reduction, internal fixation may often be achieved with a single cannulated screw and washer. Non–weight-bearing cast immobilization is indicated for several weeks after surgery for purposes of pain control and fostering undisturbed fracture healing.
Other Fracture Patterns
Type V Fracture
Type V injuries are extremely rare and appear to result from axial compression. The Salter–Harris type V injury supposedly causes partial or complete physeal arrest by virtue of a crush injury to the germinal cells of all or a portion of the physis. In such an injury, no obvious fracture of the epiphysis or metaphysis can be found, and the initial radiograph may show no evidence of injury. The diagnosis of a type V injury is therefore a retrospective one made only after premature closure has been established in a growth plate that was previously considered uninjured. It is believed that this injury causes unrecognized damage to physeal cells either directly or secondary to injury to the blood supply of the germinal cell layer of the physis.
Two cases of tibial fracture have been reported in which symmetric premature closure of the entire proximal tibial physis caused a leg-length discrepancy without any angular deformity. A compression injury to the entire physis would be unlikely unless a uniform longitudinal force were the mechanism of injury, as in a fall from a height. However, the clinical history and the configuration of the associated fractures were not consistent with a purely longitudinal force in their cases. Peterson and Burkhart believed the proposition to be speculative that premature closure of the growth plate results from compression at the time of the accident. Because the two cases cited by Salter and Harris did not have a normal radiographic appearance at the time of injury, another type could have been present. These investigators further concluded that all type V injuries reported in the literature involved the knee. On review of the literature, they concluded that the common factor in all these conditions, including the trauma cases, seemed to be prolonged immobilization. Thus an intriguing possibility is that posttraumatic physeal fusion is not always caused by direct damage to the growth plate at the time of injury but rather by factors associated with immobilization.
Peterson and Burkhart studied symmetric premature closure of the physis after trauma and found that when treated by immobilization, premature closure is more likely to be the result of ischemia secondary to immobilization rather than physeal compression. Furthermore, the type V classification may unwittingly be stifling investigation into equally plausible mechanisms of premature growth arrest. Bone scanning at the time of injury has been proposed as an investigative measure to aid and confirm a crush injury. The authors have not encountered this injury. The most severe compression injury in the authors’ experience resulted in an angular deformity ( Fig. 17-15 ).
Type VI Fracture
Ablation of the perichondrial ring has been categorized as a type VI injury. Avulsion or compression injury to the periphery of the physis is rarely seen. Lawn mower injuries and degloving injuries, which occur when the leg is dragged across concrete or pavement, may remove the perichondrial ring. The ensuing callus may cause the development of a bridge between the metaphysis and epiphysis as described by Rang. The ankle would drift progressively into varus. The authors have not encountered this fracture about the ankle.
Transitional Fractures
The juvenile fracture of Tillaux and triplane fractures are considered to be transitional fractures. These fractures occur in and about the early part of the second decade during the pubescent transition to skeletal maturity. They occur as a result of an external rotational force. The pattern of closure of the distal tibial physis (i.e., middle, medial, and lateral) is responsible for propagation of the fracture after injury.
Juvenile Fracture of Tillaux
The juvenile fracture of Tillaux is an isolated fracture of the lateral portion of the distal tibial epiphysis. It is a transition fracture and usually occurs early in the second decade, when the medial half of the distal growth plate is closed and the lateral portion remains open. This fracture is generally the result of an external rotational force. With external rotation, the anterior tibiofibular ligament holds firmly to the tibial epiphysis, which separates through the junction of the middle and lateral open physis. When displacement of the fragment is minimal, the vertical and horizontal fracture lines may be difficult to visualize. It is a Salter–Harris type III epiphyseal fracture, and mild or moderate displacement of the fragment may be present. The pattern of the injury is thought to result from the closure sequence of the distal tibial physis.
The distal physis of the tibia closes first on its medial half at the age of 13 or 14 years; the lateral part closes at 14.5 to 16 years. Closure of the distal tibial physis occurs first in the middle, then in the medial, and finally in the lateral physis. Because the lateral physis is still open, the fracture crosses through it. The fracture line extends from the articular surface proximally; it traverses the epiphysis and then continues along the physis laterally. It is equivalent to the Tillaux lesion in adults. Local tenderness and swelling may be seen over the anterolateral aspect of the distal tibial epiphysis.
A variably sized portion of the anterolateral bony epiphysis is pulled off by the anterior tibiofibular ligament when the foot is forcibly externally rotated, which is a variation of a supination–external rotation mechanism. If the fragment is large enough, a residual deformity in the joint surface may lead to an increased risk of osteoarthritis. The importance of preventing this problem in adolescents cannot be overstated.
Management
Closed reduction may be performed with analgesia and a muscle relaxant if it is done within the first 24 hours. Reduction is usually achieved by gentle internal rotation of the foot, and anatomic reduction should be attained in every case. If closed reduction is successful, the authors recommend percutaneous fixation with a threaded Steinmann pin or cannulated screw. An above-knee cast is applied for 3 weeks, followed by a below-knee walking cast for 3 weeks ( Fig. 17-16 ). If the gap after reduction appears to be less than satisfactory (>3 mm), further radiographic studies are indicated ( Fig. 17-17 ). CT scanning provides accurate assessment of the reduction; three-dimensional re-formation produces a readily interpretable image that does not require mental reconstruction of two-dimensional films and provides a permanent record of the reduction ( Fig. 17-18 ). If closed reduction is not satisfactory, open reduction with transfixion may be required. The screw or percutaneous Steinmann pin can cross the physis in this particular situation because the middle and medial sections of the growth plate are usually closed. If the growth plate is not closed or closing, the implant should not cross the physis. Growth discrepancy is an unusual sequela of this injury because most of the physis has closed. The more significant complication is arthritis resulting from either a step-off of the articular surface or a residual interfragmentary gap greater than 3 mm.
Triplane Fracture
A triplane fracture is an injury unique to the closing distal tibial growth plate. The fracture line crosses the articular surface through the epiphysis, the physis, and finally the posterior tibial metaphysis in the sagittal, transverse, and coronal planes, respectively. The multiplanar Salter–Harris type IV injury created is thought to be caused by external rotation of a supinated foot.
Radiographic Evaluation
Triplane fractures of the distal end of the tibia are sometimes quite difficult to identify on plain radiographs. AP, lateral, and mortise views should be taken. The fracture appears to be a Salter–Harris type III injury on the AP view and a Salter–Harris type II injury on the lateral projection. In the AP projection, the fracture can be seen as a vertical line crossing the central area of the epiphysis, with widening of the mortise. The appearance in this projection is remarkably similar to that of a juvenile Tillaux fracture, and care must be taken not to confuse the two. Mortise views may show more displacement than the AP ones. The apparent Salter–Harris type II fracture seen on the lateral view may be minimally displaced and occasionally obscured. This radiographic fracture pattern in a growing child should always suggest a triplane fracture. An associated fibular fracture has been shown to occur in 37% of triplane cases (40 of 107 cases). CT studies have simplified identification of all facets of this injury. Depending on closure of the distal tibial physis, the fracture may consist of one, two, or three fragments in addition to the tibial shaft ( Table 17-2 ). Thus triplane fractures are said to come in two-part, three-part, and four-part varieties. Data from five published series of triplane fractures reveal that two-part fractures are the most common, representing 60% of cases (85 of 141), three-part fractures compromise 38% (53 of 141), and four-part fractures occur only in 2% of cases (3 of 141).
| AUTHOR | YEAR | TWO-PART | THREE-PART | FOUR-PART | FIBULA |
|---|---|---|---|---|---|
| McNealy et al | 1982 | 14 | 5 | 0 | ? |
| Ertl et al | 1988 | 4 | 11 | 0 | ? |
| Rapariz et al | 1996 | 12 | 23 | 0 | 17 |
| El-Karef et al | 2000 | 12 | 6 | 3 | 5 |
| Brown et al | 2004 | 43 | 8 | 0 | 18 |
| Totals: | 85/141 | 53/141 | 3/141 | 40/107 | |
| % | 60% | 38% | 2% | 37% |
In 1957, Johnson and Fahl presented a figure illustrating a triplane injury. The nature of this unusual fracture was not appreciated until Marmor’s publication in 1970. Marmor noted widening of the ankle mortise after closed reduction of what appeared to be a Salter–Harris type II fracture. After reduction, he observed that the fracture extended in three planes—sagittal, transverse, and coronal—and involved three parts of the distal end of the tibia: the shaft, an anterolateral epiphyseal fragment, and an unattached fragment consisting of the remainder of the epiphysis with a metaphyseal spike.
The triplane fracture was named by Lynn, who reported two fractures with a three-dimensional configuration that required open reduction and internal fixation. Torg and Ruggiero also noted that the fracture was intrinsically unstable and needed internal fixation. Cooperman and colleagues thought that most triplane fractures had no free anterolateral epiphyseal fragment and were therefore two-part fractures in three planes ( Fig. 17-19 ). Dias and Giegerich postulated that the same mechanism—external rotation of the foot on the leg—causes both triplane fractures and juvenile Tillaux fractures and believed that the resulting injury was solely determined by the patient’s age. The triplane fracture occurs earlier in adolescence than the juvenile Tillaux fracture because the epiphyseal plate is still completely open in early adolescence, thus allowing the horizontal fracture to run through its entire anterior portion. In the older group, the growth plate’s medial area has already closed, so the horizontal break extends only through its anterolateral portion and is met by the vertical fracture near the closed medial epiphyseal line. If growth plate closure is more advanced, no anterolateral epiphyseal fragment is produced, and the result is a two-part fracture. Denton and Fischer described a medial triplane fracture caused by adduction and axial loading. Kärrholm stated that such a fracture type occurs at a low peak age, is associated with complications such as medial growth retardation or arrest, and stressed that it should not be confused with other types of triplane fractures. Lutz Von Laer has quite appropriately stated that a transitional fracture such as the triplane fracture “strains the spatial imagination of the surgeon.” Several authors have summarized the major triplane fracture patterns, and these findings are illustrated in Fig. 17-20 .
Intramalleolar triplane fractures have been reported. Shin and associates published a classification of intramalleolar triplane fractures and pointed out that three-dimensional CT has great advantages over plain radiographs and two-dimensional CT for evaluating this injury. They described three classes: intramalleolar, intraarticular fracture at the junction of the tibial plafond and medial malleolus (type 1); intraarticular fracture of the medial malleolus (type 2); and extraarticular intramalleolar fracture (type 3), which is the most prevalent. Operative reduction is required when intraarticular incongruity exists. None of the patterns fit into a Salter–Harris type. Ertl and associates completed a long-term (3- to 13-year) follow-up of this intraarticular fracture and found that it led to significant arthritis in adults when less than anatomic reduction was achieved. Although symptoms were absent on early follow-up, about half their patients were symptomatic at long-term evaluation. Kärrholm published the results of 21 of his cases with a 4-year follow-up and a review of the literature (209 cases); in total, about 80% displayed excellent results, 16% had minor symptoms, and 4% had more pronounced symptoms combined with degenerative changes. When the epiphyseal fracture extended into the weight-bearing arch of the ankle, residual displacement of greater than 2 mm was associated with suboptimal results. In Rapariz and associates’ series, of the 35 patients treated for triplane fractures, the only two patients in whom degenerative changes were seen in their ankle radiographs were those with residual intraarticular displacement of 3 mm. Anatomic reduction by either closed or open means is mandatory in the treatment of triplane fractures.
The choice between open and closed reduction depends on the amount of residual displacement after reduction. Impending growth arrest is not usually a consideration because the growth plate is approaching closure. Even though this fracture seems to be intrinsically unstable, it is only at the articular surface, where permanent disruption definitely predisposes to degenerative joint disease, that loss of reduction is crucial. Anatomic reduction of the articular surface is mandatory. Ertl and associates found that none of their patients with initial displacement of greater than 3 mm on AP or mortise radiographs had successful closed reduction. Interposition of soft tissue at the fracture site was responsible for the failure of closed reduction in six of eight open operations. The soft tissue was identified as periosteum in five patients and was found to be the extensor hallucis longus tendon in one. A diastasis or step-off of more than 3 mm in any plane at the articular surface requires anatomic reduction.
Management
General anesthesia is required for complete relaxation. The knee is flexed to 90°, and the foot is plantar-flexed and internally rotated. If anatomic reduction is achieved, the authors prefer percutaneous threaded Steinmann pin fixation ( Fig. 17-21 ). A cannulated interfragmentary screw may be placed over the pin with the same result. The extremity is placed in an above-knee, non–weight-bearing cast for 4 weeks, at which time the pin is removed, followed by a below-knee cast for 2 to 3 weeks.
If the interfragmentary gap after reduction is greater than 3 mm, open reduction is necessary. Open reduction is not easy and may require anterolateral and posteromedial approaches to reduce the fractures under direct visualization. Only after the posteromedial fragment is reduced can the anterolateral (Tillaux) fragment be reduced. Through an anterolateral approach, the anterolateral fragment is identified and displaced. The posteromedial fragment, if displaced, is first reduced under direct visualization by internal rotation and dorsiflexion of the foot. When reduced, the posteromedial fragment is typically fixed with a cannulated screw. If the posteromedial fragment cannot be reduced by manipulation, it should be reduced under direct visualization through a posteromedial incision. If displaced, the fibular fracture is reduced next. Finally, the displaced anterolateral fragment (Tillaux) is reduced and fixed with a cannulated screw ( Fig. 17-22 ). A non–weight-bearing, above-knee cast is applied for 3 weeks, followed by a below-knee walking cast for 4 weeks. If percutaneous Steinmann pins are used, they are removed at the time of cast changing.
Distal tibial growth is nearly complete when this injury occurs, so shortening from growth arrest is rarely a problem. Ertl and associates’ long-term reevaluation showed marked deterioration with time in ankles in which reduction of the articular surface was not accomplished. At an average of more than 6 years after injury, the result was that 15 patients had declined at least one grade. None of these patients improved during follow-up after injury to the articular cartilage. Even in individuals with anatomic reduction, delayed long-term symptoms still occurred. The symptomatic patients monitored for 20 years were only in their third decade and could experience continued deterioration. Residual 2- to 3-mm displacement of the articular cartilage in the weight-bearing area may result in late-onset degenerative arthritis.
Triplane Fracture with Ipsilateral Tibial Shaft Fracture
Jarvis and Miyanji reported on six patients with distal tibial triplane fractures in conjunction with completely separate fractures of the ipsilateral tibial shaft. The average age at the time of injury was 14 years, which is the typical age for a transitional fracture of the ankle. Contrary to conventional thinking, all injuries were secondary to low-energy falls. All tibial shaft fractures were midshaft spiral or short oblique and were minimally displaced; similarly, all but one triplane fracture were minimally displaced (gap, <2 mm). Diagnosis of the distal triplane fracture was delayed in two cases. Although all patients in the study were treated satisfactorily with closed reduction and casting with the ankle in internal rotation, the treatment may vary based on patient and fracture characteristics. The authors have treated three patients with this combination and would recommend dedicated radiographs of the ankle in an adolescent with a tibial shaft fracture ( Fig. 17-23 ). Because of the injury’s potential for long-term sequelae, a high index of suspicion should be maintained so that this rare combination is not missed.
Extensor Retinaculum Compartment Syndrome
Mubarak described extensor retinaculum syndrome of the ankle after injury to the distal tibial physis in six children aged 10 to 15 years. All had sustained a Salter–Harris type II or type IV fracture (triplane fracture) with anterior displacement of the tibia into the tunnel of the superior extensor retinaculum. The clinical findings related to compartment syndrome included severe pain and swelling of the ankle, hypoesthesia or anesthesia in the first web space, weakness of extensor halluces longus and extensor digitorum communis, and pain with passive flexion of the great toe. Three patients were seen with a displaced fracture and the clinical finding of extensor retinaculum syndrome, whereas three patients developed symptoms 24 to 48 hours after reduction and internal fixation of the fracture. Compartment syndrome was confirmed by measurement of intracompartmental pressures under general anesthesia after fracture reduction, which was greater than 40 mm Hg beneath the superior extensor retinaculum but less than 20 mm Hg in the anterior compartment. All patients had relief of their symptoms within 24 hours of treatment, which consisted of release of the superior extensor retinaculum with a 10- to 12-cm longitudinal incision over the distal tibia and fracture stabilization (see Fig 17-1 ). The inferior extensor retinaculum should not be released because bowstringing of the extensor tendons at the ankle may occur ( Fig. 17-24 ). After surgical decompression, one patient developed osteomyelitis and two patients had persistent weakness of the extensor hallucis longus and hypoesthesia in the first web space. On the basis of a cadaveric study, Haumont and colleagues confirmed the anatomic cause of extensor retinaculum syndrome: they found that the muscle fibers of the extensor hallucis longus extend under the superior extensor retinaculum and that the region is more susceptible to ischemia if the blood supply in this area is tenuous. They recommended ankle immobilization in neutral dorsiflexion (0°) to decrease the risk of compartment syndrome because fewer muscle fibers extend under the retinaculum in this position.
Dislocation of the Ankle Joint
Ankle dislocation without a fracture is a rare event that has prompted isolated case reports in the literature. Most dislocations are posteromedial and manifest as open injuries on the anterolateral side of the joint, with gross disruption of the lateral capsular ligamentous complex ( Fig. 17-25 ). The majority of patients are young adults; few ankle dislocations have been reported in children. Nusem and associates reported a closed posterior ankle dislocation in a 12-year-old girl that was successfully treated with closed reduction and a short leg cast. Most posterior or medial dislocations are stable in neutral or slight dorsiflexion. In this position, the torn lateral ligamentous complex is approximated. Although the dislocation is invariably posteromedial, rarely is repair of the deltoid ligament necessary, and stability usually occurs.
The mechanism of injury is generally marked plantar flexion with inversion. Local distraction occurs anterolaterally, with rapid rupture of the lateral ligamentous complex from front to back or through the fibular physis in children. This injury is akin to a flexion–distraction injury in the spine. In addition to separation of the lateral ligamentous complex, the physis, or both, the skin, extensor tendons, and neurovascular structures frequently rupture in an open dislocation. As the plantar-flexed foot is carried into inversion, varus tilting and rotation of the talus occur, followed by dislocation, usually in the posteromedial position. The deltoid ligament is always injured; however, except in cases of gross displacement, it usually retains a significant amount of integrity and provides a posteromedial hinge that affords stability when the ankle is reduced and held in dorsiflexion.
Most of these injuries are open, and débridement and irrigation of the joint are required. In an adult, the lateral ligamentous structures are repaired; however, in a child, in whom the injury is transphyseal through the fibula, the AP and lateral talofibular ligaments appear to be intact, and anatomic reduction and fixation of the fibular physis are normally all that is necessary. The wound may be closed over a drain if the soft tissues will allow it; otherwise, delayed primary closure and possibly skin grafting are required. The ankle is placed in a compressive protective dressing for 7 to 10 days, after which a non–weight-bearing cast in the neutral plantigrade position is worn for 4 to 6 weeks. After cast removal, progressive weight-bearing is permitted after rehabilitation restores ankle motion, strength, and proprioception.
Complications of Injuries to the Distal Tibial and Fibular Growth Plates
Angular Deformity Secondary to Asymmetric Arrest of the Distal Tibial Growth Plate
The deformity is usually varus and is most frequently seen after Salter–Harris type III and IV medial malleolar injuries. An adduction injury most commonly results in a varus deformity. After an adduction injury, a direct compressive force applied to the epiphyseal plate by the talus results in premature closure of that part of the plate and subsequent angular deformity ( Fig. 17-26 ). Anatomic reduction by open or closed means is necessary when the fracture involves the medial malleolus (Salter–Harris type III or IV) because incomplete anatomic reduction results in later deformity. Anatomic reduction and fixation usually prevent this problem. Creative opening or closing wedge osteotomies have been used successfully to lessen minimal leg-length discrepancy caused by partial growth arrest. Epiphysiodesis of the distal ends of the tibia and fibula may be performed to prevent an angular deformity if the child has less than 2 years of growth remaining. Correction by epiphysiolysis (also known as physeal bar resection) may be successful if less than 50% of the cross-sectional area of the physis is involved. If greater than 10° to 20° of angular deformity has occurred, multiple authors recommend also performing a corrective osteotomy at the time of physeal bar resection. Epiphysiolysis is an adequate if not excellent procedure when partial growth arrest of the distal part of the tibia has occurred. The child should have 2 or more years of growth remaining. Traditionally, CT has been the most common imaging method used to determine the size of the physeal bar. MRI is another modality for imaging physeal bars. The amount of involvement of the growth plate can be documented graphically by the use of anterior and lateral polycycloidal tomography to map the physeal bar. Imaging data can be processed to yield both three-dimensional–rendered and projection physeal maps that are particularly useful in preoperative planning ( Fig. 17-27 ). Careful evaluation of MRI information regarding physeal bar size is recommended as one of the authors (C.T.M.) is aware of instances in which size underestimation has occurred ( Fig. 17-28 ).
Even though the attending physician has made the family aware of the potential for physeal arrest or has discussed the radiographs demonstrating angulation of the Park–Harris growth arrest line, if the child does not complain of pain, that child may not be returned for follow-up. Most often, the child is seen sometime later because of the development of a varus deformity. The technique of placing a proximal window in the metaphysis and approaching the bar from above for central bars and directly for peripheral ones has been successful. It is most important that the bar be completely excised and that, after excision, normal-appearing physeal cartilage be identified circumferentially. An interposition substance is necessary to prevent rebridging, and subcutaneous fat or methyl methacrylate (Cranioplast) has been used most often. Methyl methacrylate appears to be a more attractive option because it allows immediate weight-bearing. However, if indicated, removal of the interpositional substance may be difficult. Compromised host immunity has been associated with release of the methyl methacrylate monomer. If the angular deformity of the ankle exceeds 20°, a corrective osteotomy should be included. Nearly normal longitudinal growth and correction of moderate angular deformities can be expected with bridges that occupy less than 25% of the physis. It is important to place metallic markers (a small Steinmann pin or vascular clip) into the epiphysis and metaphysis to determine whether growth results from the epiphysiolysis. Berson and colleagues suggested a decision-making process that they used to divide their 24 patients into three groups: group 1 consisted of children with less than 2 years of growth remaining, less than 9° of predicted angulation, and less than 2 cm of predicted discrepancy. This group was treated by observation. Group 2 consisted of children with less than 9° of existing angulation, more than 2 cm of predicted leg-length discrepancy, or more than 9° of predicted angulation. This group was treated with bilateral distal tibial and fibular epiphysiodesis. Group 3 consisted of children with more than 9° of existing angulation and greater than 2 cm of predicted leg-length discrepancy. This group was treated by osteotomy to correct the angulation and either lengthening or epiphysiodesis to correct the leg-length discrepancy. They did not include physeal bar excision because they did not have great success with it. This approach resulted in satisfactory correction in 22 of 24 patients.
Takakura and colleagues reported their results after opening wedge osteotomy for the treatment of posttraumatic varus deformity of the ankle. A corrective osteotomy was indicated for children only when they had ankle pain after walking for long distances, had difficulty participating in sports, and had a progressive deformity as well as uneven wear of the sole of the shoe, with more rapid wear on the lateral part. In four of the nine cases discussed, the initial injury was an epiphyseal fracture of the distal end of the tibia. The average age of these patients was 14 years, and the average follow-up was 9 years. The tibial shaft and the tibial joint surface angle (TAS angle) on the AP radiograph was an average of 73° in this group (this angle is 88° in healthy Japanese). The ankle joint radiographs also showed evidence of subchondral sclerosis and osteophyte formation. The osteotomy was performed 2 to 3 cm proximal to the epiphyseal plate, and an oblique osteotomy of the fibula was performed first ( Fig. 17-29 ). The space created anteromedially was filled with iliac crest bone graft. The average time for osseous union was 6.5 weeks, and the average postoperative TAS angle was 89°. Improvement in leg-length discrepancy was also reported. On latest follow-up, these patients were able to participate in physical education classes at school, and two of them were able to participate in competitive basketball and athletic activities.
Foster and colleagues published a report on the early use of free fat interpositional grafts in severe physeal injuries of the distal end of the tibia, particularly in injuries with complete peripheral detachment of the zone of Ranvier. The physeal, cancellous epiphyseal, and metaphyseal debris was removed, fractures were stabilized, and fat grafting was performed. After an average follow-up of 4 years (for distal tibial injuries), no angular deformity of the leg was present, and the distal tibial growth plate remained open.
Angular Deformity Secondary to Growth Arrest of the Distal Fibular Growth Plate
Growth arrest of the distal fibular physis is a rare complication of distal fibular growth plate fractures. This complication may result in valgus malalignment of the ankle joint. When the deformity is detected early, screw epiphysiodesis of the distal tibial physis may suffice; otherwise, a corrective osteotomy aimed at leveling the joint surface is necessary ( Fig. 17-30 ).
