Foot and Ankle Trauma
David B. Thordarson
Although foot and ankle injuries are not life threatening, the long-term disability resulting from them is well established. Two studies have compared multiply injured patients with and without foot injuries and found that those who survive their injuries are far more impaired functionally if they had a foot injury in addition to multisystem trauma. This chapter provides a summary of foot and ankle trauma, including the mechanism of injury, clinical presentation, appropriate radiographic evaluation, and classification and treatment for fractures and dislocations of the foot and ankle region.
ANKLE FRACTURES
PATHOGENESIS
Although technically ankle fractures include any injury to the ankle joint, fractures involving the weight-bearing dome (plafond—pilon fracture) are discussed in a separate section because they have a far worse prognosis and are more difficult to treat. The usual mechanism of injury for most ankle fractures is a rotational injury to the ankle. The position of the ankle at the time of injury and subsequent direction of force generally dictates the fracture pattern. These mechanisms are highlighted in the classification systems (e.g., Lauge—Hansen), which are discussed subsequently. Special cases include severe external rotation injuries to the ankle when in neutral position, which can lead to syndesmotic injuries, associated on occasion with high fibular fractures (Maisonneuve).
DIAGNOSIS
Physical Examination and History
Clinical Features
Patients should present with a mechanism of injury consistent with an ankle fracture. Occasionally, a diabetic patient presents with a history of little or no trauma, which should raise the suspicion of Charcot neuroarthropathy. Other pertinent historical factors besides the mechanism include medical comorbidities such as diabetes and peripheral vascular disease, which could complicate wound healing, and use of tobacco, which can interfere with wound and fracture healing.
Physical examination is pertinent for the presence of deformity and the amount of soft-tissue swelling.
Occasionally, injuries are open; these should clearly be noted and treated on priority.
Neurovascular status should likewise be noted, especially in the presence of dislocation that increases the likelihood of neurovascular compromise.
Radiologic Features
A standard radiographic series of the ankle, including an anteroposterior (AP), lateral, and mortise radiograph, is generally sufficient to classify these injuries and plan treatment.
Occasionally, if a patient has more proximal leg tenderness or medial clear space widening with no obvious fibular fracture, full-length radiographs of the tibia and fibula should be obtained to rule out the presence of a high fibular fracture as in the case of a Maisonneuve injury.
Classification
Two common classification systems are used for rotational ankle fractures. The Dennis—Weber classification system is shown in Table 14.1 (Figs. 14.1,Figs. 14.2 and Figs. 14.3). In the Lauge—Hansen system (Table 14.2 and Fig. 14.4), the classification describes the position of the foot at the time of injury and the deforming force with the resultant injury pattern.
TREATMENT
Initial treatment for all displaced ankle fractures is closed reduction and placement of a splint or cast.
If anatomic reduction of the joint is achieved the fracture can be treated closed, generally with 6 weeks in a short nonwalking cast followed by a variable period of protected weight bearing in a cast or removable boot.
Regular follow-up is necessary to rule out redisplacement of the fracture fragments during fracture healing
A special case exists with SER type II injuries in which there is no medial ankle injury. These are stable injuries and can be treated with weight bearing as tolerated throughout the course of treatment usually in a cast or boot, but some have advocated using just a stirrup brace for protection.
Persistent displacement after closed reduction of greater than 1 to 2 mm of the talus should be treated with operative reduction if there is no medical contraindication. Previous studies have demonstrated a significant increase in intra-articular contact stresses with minimal residual displacement of the talus. One study demonstrated that displacement of the fibula in a PER fracture model increases contact stresses most with shortening of the fibula, followed by lateral translation, and external rotation.
TABLE 14.1 THE DENNIS-WEBER CLASSIFICATION SYSTEM FOR ROTATIONAL ANKLE FRACTURES | ||||||||
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 Figure 14.1 AP (A) and lateral (B) X-rays demonstrating Weber A fracture of the ankle. Note transverse fracture of fibula below the level of plafond and vertical fracture of the medial malleolus. |
 Figure 14.2 AP (A) and lateral (B) X-rays demonstrating Weber B fracture of the ankle. Note the bimalleolar pattern with transverse fracture of the medial malleolus and oblique fracture of fibula beginning at the mortise. |
 Figure 14.3 AP (A) and lateral (B) X-rays demonstrating Weber C ankle fracture. Note fibular fracture above the level of the plafond with intact medial malleolus in this case. |
In general, bimalleolar fractures are not amenable to closed reduction and casting because there is no stable direction to reduce the ankle (Fig. 14.5). PER fractures have a higher rate of persistent displacement because the ligaments are disrupted to the level of the fibular fracture. In general, the higher the level of the fibula fracture, the greater the amount of instability.
In addition to anatomic reduction of the fracture site, syndesmotic stability must be assessed following operative reduction. Most surgeons advocate intraoperative stability assessment after plating fibular fractures above the level of the ankle where syndesmotic and interosseous membrane
injury have occurred (Fig. 14.6). Less stability is present in patients with deltoid ligament rupture rather than a medial malleolus fracture because internal fixation of the medial malleolar fragment does restore some degree of medial stability through the attached deltoid ligament. In cases of deltoid ligament rupture or higher fibular fracture, especially more than 4.5 cm above the joint, a greater degree of syndesmotic instability usually persists after fixation of the fibular fracture.
injury have occurred (Fig. 14.6). Less stability is present in patients with deltoid ligament rupture rather than a medial malleolus fracture because internal fixation of the medial malleolar fragment does restore some degree of medial stability through the attached deltoid ligament. In cases of deltoid ligament rupture or higher fibular fracture, especially more than 4.5 cm above the joint, a greater degree of syndesmotic instability usually persists after fixation of the fibular fracture.
TABLE 14.2 LAUGE-HANSEN CLASSIFICATION SYSTEM FOR ROTATIONAL ANKLE FRACTURES | ||||||||||||||||
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 Figure 14.4 A—D: Lauge—Hansen classification of ankle fractures. Note the subclassifications for each fracture type (from 1 to 4). Supination—adduction pattern correlates with Weber A, SER pattern correlates with Weber B, and PER fracture correlates with Weber C. The position of the foot at the time of injury is either in supination or pronation, and the direction of force causing the fracture is the second part of the name (i.e., external rotation or adduction/abduction). (From Weber ME. Ankle fractures and dislocations. In: Chapman MW, ed. Operative orthopaedics. Philadelphia: JB Lippincott, 1988:471-485.) |
 Figure 14.5 Postoperative AP (A) and lateral (B) X-rays demonstrating fixation of bimalleolar Weber B SER ankle fracture. |
 Figure 14.6 Intraoperative external rotation stress view with Weber B—SER IV equivalent fracture. Note marked medial instability indicating ruptured deltoid ligament thus an unstable fracture pattern. |
 Figure 14.7 AP X-ray of patient who underwent open reduction and internal fixation (ORIF) of Weber C—PER IV ankle fracture with standard medial and lateral plate fixation and stainless steel 3.5-mm cortical screw through three cortices. |
 Figure 14.8 Mortise and lateral X-ray following fixation of high fibular fracture (Maissoneuve fracture) with stainless steel 3.5-mm cortical screw and flexible suture button device (Tightrope; Athrex, Maples, Florida). |
In those cases, most surgeons place a syndesmotic screw to stabilize the syndesmosis while soft-tissue healing occurs. No consensus exists regarding the method of stabilization with some surgeons using smaller (3.5 mm) versus larger (4.5 mm) screws or three-cortex versus four-cortex fixation following these injuries (Fig. 14.7). In addition, some have begun to use suture button devices as they are flexible and do not
require removal (Fig. 14.8). Controversy also exists over the necessity and timing for removal of syndesmotic screws; I prefer to leave syndesmotic screws in for 3 to 4 months following operative treatment of a fracture, but patients are allowed to begin weight bearing 6 weeks after operative fixation. Some surgeons routinely leave syndesmotic screws in place.
require removal (Fig. 14.8). Controversy also exists over the necessity and timing for removal of syndesmotic screws; I prefer to leave syndesmotic screws in for 3 to 4 months following operative treatment of a fracture, but patients are allowed to begin weight bearing 6 weeks after operative fixation. Some surgeons routinely leave syndesmotic screws in place.
Results
In general, the results following an anatomic reduction of a displaced ankle fracture are good. Posttraumatic arthritis can develop despite an anatomic reduction, most likely as a result of chondral injury sustained at the time of initial injury. One arthroscopic study found 79% of patients to have some degree of chondral injuries, especially in patients with Weber C-PER fractures. Some degree of stiffness is to be anticipated, with most patients resuming full activities following healing of these fractures. Some studies have noted some functional deficits 1 or even 2 years after an uncomplicated ankle fracture.
PILON FRACTURES
PATHOGENESIS
Tibial pilon fractures involve the weight-bearing surface of the distal tibia or adjacent tibial metaphyses. These fractures are the most serious injuries involving the ankle joint because they disrupt the weight-bearing surface of the joint. The usual mechanism of injury is an axial load, either because of a fall from a height or a motor vehicle accident with the foot hitting the floorboard. Some are because of lower-energy injuries without significant impaction when a significant rotational component splits the articular surface. The complexity of their articular injury and the limited nature of the soft tissue of the distal tibia contribute to a high rate of wound complications following surgical treatment.
DIAGNOSIS
Physical Examination and History
Most patients who have sustained a tibial pilon fracture present with a history of high-energy trauma to the lower extremity.
There is a relatively high incidence of associated musculoskeletal and other system trauma owing to the high-energy nature of this injury.
Occasionally, patients report a severe rotational injury, such as may occur while skiing, that can lead to a split rather than an axial load of the plafond with a better prognosis.
In addition to delineating the mechanism of injury, the history should evaluate associated medical conditions that may increase the risk of wound-healing problems, such as diabetes or peripheral vascular disease.
The use of tobacco, which leads to increased wound-healing problems and poorer bone healing, should also be evaluated.
Clinical Features
Open injuries should be documented and urgently managed with surgical irrigation and debridement.
Otherwise, the magnitude of soft-tissue swelling and the presence of fracture blisters should be noted. Fracture blisters are of two types:
Clear fluid-filled blisters—cleavage injury at the dermal-epidermal junction with areas of retained epithelial cells leading to faster reepithelialization
Blood-filled blisters—more significant injury without areas of retained epithelial cells with higher rate of wound complications when surgery is performed through these areas
In general, blisters should be allowed to reepithelialize before an incision is made through these areas.
Radiologic Features
Standard AP and lateral radiographs of the ankle are mandatory in all of these patients to assess the degree of damage to the joint surface, fibula, and adjacent metaphyseal-diaphyseal bone.
Occasionally, oblique radiographs can be helpful to further delineate the fracture anatomy.
CT scanning is helpful for preoperative and intraoperative planning and treatment and to provide a more accurate prognosis regarding eventual surgical outcome by determining the degree of comminution of the articular surface.
Classification
Two classifications are commonly used to describe tibial pilon fractures—the Rüedi-Allgöwer classification (Table 14.3 and Fig. 14.9) and the AO-OTA classification (Table 14.4 and Fig. 14.10).
TREATMENT
Most tibial pilon fractures are displaced and thus necessitate operative reduction to restore the weight-bearing surface of the tibial plafond. On the rare occasion of a
type I Rüedi-Allgöwer fracture with no displacement, it can be treated with a short leg nonwalking cast for approximately 6 weeks before being advanced to weight-bearing protection.
type I Rüedi-Allgöwer fracture with no displacement, it can be treated with a short leg nonwalking cast for approximately 6 weeks before being advanced to weight-bearing protection.
TABLE 14.3 RÜEDI-ALLGÖWER CLASSIFICATION OF TIBIAL PILON FRACTURES | ||||||||
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Because of the high rate of wound complications after operative treatment of these complex fractures with an impaired soft-tissue envelope and frequent presence of blisters, definitive surgical reconstruction of the tibial articular surface is usually delayed until soft-tissue swelling has improved. More recent reports have yielded lower wound complication rates by using a transportable external fixator for provisional fixation. This technique involves placing a provisional external fixator along the medial aspect of the ankle to pull the soft tissues out to length, with most surgeons treating the fibula with ORIF at the time of placement of the medial external fixator because the lateral soft tissues are generally not as compromised as the distal pretibial soft-tissue envelope.
Definitive fixation of the plafond is delayed until adequate edema resolution has occurred, which can range from 5 to 21 days in most cases.
TABLE 14.4 AO-OTA CLASSIFICATION OF TIBIAL PILON FRACTURES | ||||||||
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 Figure 14.9 Schematic representation of Rüedi-Allgöwer classification system of tibial pilon fractures. (Adapted from Müeller ME, Allgower M, Schneider R, et al., eds. Manual of internal fixation: techniques recommended by the OA—ASIF group, 3rd ed. New York: Springer-Verlag, 1991:279.) |
Surgical Treatment
Definitive surgical fixation generally includes open reduction and plate fixation, emphasizing biologic principles of minimal soft-tissue stripping of the soft tissues and bony fragments.
Open Reduction with Plates
This method of treatment has more or less supplanted use of an external fixator associated with problems of pin track infections, less direct control of the bony fragments, and poorer patient acceptance. Recent studies emphasizing biologic principles using indirect reduction techniques that use soft-tissue attachments to facilitate the reduction with distraction across the surgical site intraoperatively, use meticulous soft-tissue technique, emphasizing a tension-free closure, and have lead to acceptable wound complication rates.
Surgical incisions that allow adequate access to address the various fracture patterns are planned. An anterolateral approach has become the most common one used by many surgeons in the recent times (Fig. 14.11).
When more than one incision is used, as larger a skin bridge as is feasible is made to minimize the risk of skin necrosis.
Use of specialized low-profile, locking plates specifically designed for the tibial diaphysis, either anterolaterally or medially, have led to more stability, less soft-tissue tension, lower incidence of symptomatic hardware, and, combined with the aforementioned techniques, a lower wound complication rate (Fig. 14.12).
The joint surfaces are reconstructed from deep to superficial. As the reduction progresses, the deeper articular structures are no longer visible after the more superficial structures are reduced.
Preoperative CT scans help to localize the incisions directly over a fracture plane to minimize soft-tissue stripping necessary to mobilize the fragment (Fig. 14.13).
With a significant diaphyseal extension, subcutaneous plating methods wherein a small incision is made distally and a plate is slid along the subcutaneous border of the tibia with percutaneous screws placed into the plate proximally helps to minimize soft-tissue trauma (Fig. 14.14).
This technique is facilitated by having a high-quality fluoroscopy unit with laser-targeting of the proximal holes to help localize the stab incision sites for proximal screws.
 Figure 14.10 Schematic representation of AO-OTA classification of tibial pilon fractures. (Adapted from Orthopaedic Trauma Association Committee for Coding and Classification. Fracture and dislocation compendium. J Orthop Trauma 1996;10(suppl 1):S57.) |
 Figure 14.11 Photograph demonstrating anterolateral exposure with anterior locking plate. The superficial peroneal nerve can be seen coursing obliquely across the surgical wound proximally. |
Complications
Wound Complications
Potentially catastrophic wound complications with subsequent infection and osteomyelitis can develop after treatment of pilon fractures when operating through the compromised soft-tissue envelope.
The most important concept with regard to wound complications is to avoid them by delaying surgery with a temporary external fixator until the soft-tissue envelope is healthier (blisters are healed and soft-tissue edema is improved), performing a tension-free closure at the time of surgery, and using meticulous soft-tissue technique during the procedure.
Superficial skin necrosis is treated with local wound care.
Full-thickness skin loss with exposure of underlying bone and hardware mandates aggressive treatment, most likely with free flap coverage.
 Figure 14.12 AP and lateral radiographs following anterolateral plating of intra-articular type IIC pilon fracture with lateral fibular plating. |
Osteomyelitis
Osteomyelitis generally develops only in patients with significant wound complications.
The best treatment is avoidance by prompt treatment of deep wound dehiscences with exposed bone and hardware.
Chronic osteomyelitis must be managed with aggressive debridement and bone grafting, which usually necessitates an ankle fusion in cases that are salvageable.
Below-knee amputation is often the best salvage option in patients with chronic osteomyelitis.
Arthrosis and Stiffness
Stiffness after tibial pilon fracture is because of a varying amount of posttraumatic fibrosis and arthrosis.
Although anatomic reduction and stable fixation allows for early range of motion (ROM) to help minimize stiffness, this is still a relatively common complication. It is a particularly difficult problem to treat, short of fusing the ankle joint.
Nonunion, Delayed Union, and Malunion
Nonunion of the metaphyseal-diaphyseal junction is not uncommon in patients with these complex, high-energy injuries.
If healing is not evident by 12 weeks, bone grafting of the fracture site should be considered (Fig. 14.15).
Malunions are relatively common and are best avoided by creating a stable fracture construct at the time of initial treatment.
Posttraumatic Arthritis
Many studies have documented nearly all cases to have some degree of radiographic evidence of varying degrees of posttraumatic arthritis after pilon fractures. Some have shown a correlation between fracture type, incidence of posttraumatic arthritis, and poor results.
The quality of the fracture reduction in some studies has correlated with clinical results.
Results and Outcome
In general, results after tibial pilon fractures correlate most closely with the initial displacement, that is, amount of initial trauma. Anatomic reduction without a wound complication postoperatively leads to the greatest likelihood of a good result, but an anatomic reduction does not guarantee a good result. In one prospective randomized study, all patients who had a type II or III Ruedi fracture had some degree of radiographic joint space narrowing at a minimum follow-up of 2 years. In another recent study, at 5 and 12 years after surgery, 27 of 31 patients were unable to run and 14 had changed jobs, but few had secondary reconstructive procedures. On average, these patients improved for 2.4 years after injury.
FRACTURES OF NECK AND BODY OF THE TALUS
PATHOGENESIS
Fractures of the neck and body of the talus account for approximately 50% of significant injuries of the talus.
Generally, they are associated with high-energy trauma such as motor vehicle accidents or fall from a height. The theoretical mechanism is hyperdorsiflexion of the neck of the talus with impaction of the neck or body against the anterior lip of the tibia, although it is difficult to recreate this fracture in the laboratory with this mechanism.
Generally, they are associated with high-energy trauma such as motor vehicle accidents or fall from a height. The theoretical mechanism is hyperdorsiflexion of the neck of the talus with impaction of the neck or body against the anterior lip of the tibia, although it is difficult to recreate this fracture in the laboratory with this mechanism.
 Figure 14.13 A: Preoperative AP X-ray demonstrating pilon fracture with high segmental fibular fracture with significant joint involvement. B: Preoperative lateral radiograph. C: Preoperative CT scan, transverse CT cut just proximal to the articular surface of the plafond. D: Postoperative AP X-ray demonstrating fixation of tibia and fibula with a low-profile plate. E: Postoperative lateral X-ray of the same patient. |
The vascular anatomy of the talus is pertinent because the limited blood supply to the body can predispose patients to avascular necrosis (AVN) following fracture. With no tendinous attachments and approximately two-thirds of its surface covered with articular cartilage, it has a limited area for blood supply to enter. The arterial blood supply derives from the following:
Artery of the tarsal canal—a branch of the posterior tibial artery, supplies medial half to two-thirds of the body
Artery of the sinus tarsi—formed from a branch of the anterior tibial and peroneal arteries, forming an anastomotic sling with the artery of the tarsal canal under the talar neck
Deltoid arterial branches—branch of the arterial tarsal canal that enters medially with the deep deltoid ligament and may be the only remaining blood supply in displaced fractures of the neck or body of the talus
 Figure 14.14 A: Photograph demonstrating percutaneous incision, approximately 7 cm in length before insertion of this medially based pilon plate. Note percutaneous tenaculum holding plate to bone in center of picture and depth gauge in wound where a percutaneous screw was placed. B: AP fluoroscopic view intraoperatively confirming plate is on bone while localizing screw hole at proximal tip with hemostat. C: AP radiograph of the same patient after placement of percutaneous pilon plate. Note large segment of bone without fixation that was not exposed intraoperatively, which led to rapid fracture consolidation postoperatively owing to lack of periosteal stripping. |
 Figure 14.15 Postoperative X-ray 4 months after surgery demonstrating nonunion of metaphyseal-diaphyseal portion of a plafond fracture. |
DIAGNOSIS
Physical Examination and History
Patients report a high-energy trauma.
Many patients have associated musculoskeletal trauma resulting from the high-energy nature of this injury with medial malleolar fractures reported in 20% to 50% of these patients.
Clinical Features
On examination, fracture displacement and possible dislocation of the talus can be masked by rapid onset of swelling.
The body of the talus can be palpable subcutaneously in the posteromedial ankle in severe cases.
Neurovascular structures are usually spared from serious injury.
There is a relatively high incidence of open injuries in these patients.
 Figure 14.16 Diagram of proper orientation and position of foot for obtaining Canale view that demonstrates varus—valgus alignment of the talar neck. Note the ankle is in maximal plantarflexion, foot pronated is 15°, and X-ray beam is angled cephalad 75° relative to cassette. |
Radiologic Features
The fracture is usually readily apparent from AP and lateral radiographs of the talus.
Varus or valgus displacement of the talar neck is best seen on a modified Canale view (Fig. 14.16).
Classification
Talar neck fractures are classified with the Hawkins classification (Table 14.5 and Fig. 14.17).
TREATMENT
In the Hawkins I fracture, the ankle can be placed in neutral position with no evidence of displacement.
On these rare occasions, patients can be kept in a cast for approximately 8 weeks followed by an additional month of protection with a controlled active motion walker. An apparent nondisplaced fracture that displaces with the ankle placed in neutral position is actually a Hawkins II fracture.
A Hawkins II fracture (Fig. 14.18) should be promptly treated with closed reduction.
Maximum plantarflexion and traction of the foot will usually realign the head with body fragment.
Varus or valgus stress realigns the neck in the transverse plane.
A near-anatomic reduction allows a delay in surgical treatment.
Hawkins III fractures with a dislocated body of the talus should be taken directly to surgery because the likelihood of successful closed reduction is negligible (Fig. 14.19).
Operative treatment of these fractures should use a combined anteromedial—anterolateral approach.
Anteromedial incision—anterior aspect of the medial malleolus, dorsal aspect of the navicular tuberosity, which exposes the medial neck.
Anterolateral incision—from anterior tip of the fibula to base of the fourth metatarsal, exposing the lateral neck of the talus and allowing access to the subtalar joint.
Fixation is generally with 3.5-mm fully threaded cortical screws for neutralization in contrast to lag fixation to prevent displacement into varus if medial comminution is present (Fig. 14.20).
Titanium screws allow for postoperative MRI (Fig. 14.21).
Although screws inserted from posterior lead to greater biomechanical stability, they necessitate a third incision (which is difficult with the patient in the supine position) as the two anterior incisions are necessary for reduction; in my opinion, this is not necessary.
Hawkins III fractures require a longer medial incision and generally require medial malleolar osteotomy to facilitate reduction if the malleolus has not been fractured.
A traction pin should be placed in the inferior aspect of the calcaneus to facilitate reduction of the body of the talus into the mortise.
With talar body fractures, medial malleolar osteotomies are often necessary to facilitate exposure and reduction of the body of the talus, because the malleoli preclude adequate visualization of the fracture (Fig. 14.22).Related posts:
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