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Timothy R. Daniels, M.D., FRCSC
Toronto, ON Open injuries of the foot and ankle are not as common as open fractures of the long bones and, thus the orthopaedic surgeon manages this problem less frequently. Nevertheless, it is important to adhere to the basic principles that apply to all open fractures: (i) adequate antibiotics, (ii) early irrigation and debridement, (iii) limited dissection of the soft tissue envelope, (iv) adequate reduction with stable fixation, (v) early coverage of tendons, nerves and exposed hardware, (vi) repeat debridement if necessary.
Open Ankle Fractures
Open ankle fractures are encountered more often than any other open injury to the foot and ankle areas. This is in large part due to the subcutaneous location of the malleoli and the severe angular deformities that can result at the time of injury. The location of the wound is usually directly over the lateral or medial malleoli. In the majority of cases, the wound is created by the proximal fragment protruding through the skin followed by the skin being torn longitudinally or transversely around the bone. The laceration is linear with minimal damage to the surrounding soft tissues. The periosteum of the exposed bone is often intact and the skin edges viable.
 Figure 1
Anteroposterior radiographs of an infected nonunion following an open talar neck fracture. At the time of injury the patient presented with an open talar neck fracture (Hawkins type III) that was managed with irrigation, debridement followed by open reduction with K-wire fixation. One year following injury the patient had deve-loped an infected nonunion of the talar neck with avascular necrosis of the entire talar body.
The talar body has been excised and external fixators applied. Osteoset-T beads were placed in the tibia where a Brodies abscess was present and cement beads mixed with tobramycin powder at the ankle joint. After a
second opinion the patient opted for a below-knee amputation. | I proceed with immediate open reduction and internal fixation without leaving the hardware exposed. If the wound is medial, two partially threaded 4.0 mm cancellous screws are inserted; if the wound is lateral, either two intramedullary K-wires or a rush-rod are used to stabilize the fibula. Care must be taken to restore length. I prefer intramedullary fixation to plates and screws if wound coverage is an issue. If possible, the wound should be closed over the exposed bone leaving the distal portion open. In high-energy injuries with significant soft tissue damage, partial closure of the wound may not be possible. In this circumstance, early intervention with skin graft, local flaps or free-flaps is required. I have rarely used temporary or definitive external fixation on open ankle fractures; however, this is an option if the degree of soft tissue damage or extensive comminution does not allow for early internal fixation.
Open Pilon Fractures
Open pilon fractures are associated with greater soft tissue injury than open malleolar fractures. They are challenging injuries with a significant risk of amputation if complications arise.
I often proceed with thorough irrigation and debridement followed by temporary stabilization with a spanning external fixator. If possible, an intra-articular reduction with minimal soft tissue dissection is performed using K-wires and screws for fixation. It is important to obtain proper length and axial alignment with the external fixator, for this may be the definitive method of stabilization if the soft tissues do not allow for delayed open reduction and internal fixation. The patient is booked for repeat irrigation and debridement in 48 hours and plastic surgery is consulted. If the soft tissues recover adequately, the fixator is removed in 10 to 14 days and the fracture reduced and stabilized with plates. I have been using the method of percutaneous plate fixation on the tibia with increasing frequency. The results, thus far, have been more than satisfactory. Proper coverage of the wound is performed following reduction and plating.
 | Figure 2
Lateral radiograph of an open calcaneal fracture with severe comminution. Patient was treated with irrigation and debridement with casting. MRI and CT scan one year after injury demonstra-ted severe comminution, nonunion of multiple calcaneal fragments and avascular necrosis of the entire talus. Patient opted for a below-knee amputation. | Open Talar Fractures
Open fractures of the talus, particularly with extrusion of a portion of the talus (open Hawkins type III), are catastrophic injuries. Even with the best possible outcomes, patients are often left with symptomatic end-stage arthritis of the hindfoot that requires a salvage procedure. In the most severe cases, large portions of the talar body and/or neck can be missing (Figure 1). Each case must be managed individually. Many factors must be taken into account when developing a treatment plan: (1) the fracture pattern, (2) the extent of comminution and bone loss, (3) the degree of contamination, (4) associated neuro-vascular injury, (5) associated injuries, (6) age of the patient, (7) co-morbidities and (8) patient expectations. Urgent management of the fracture is indicated; therefore, all of the aforementioned factors may not be appropriately addressed prior to an operative intervention.
I proceed with an open reduction and, if bone loss is present, a spanning external fixator is applied. The family and patient are then extensively consulted. In the presence of bone loss, the surgical options are a primary arthrodesis or below-knee amputation. The primary arthrodesis can be performed in the standard fashion with bone grafting or by a proximal tibial corticotomy and application of a ring fixator followed by transportation of the tibial to the calcaneus. My experience has found that patients who have opted for a primary below-knee amputation are the most satisfied with their outcome.
Open Calcaneal Fractures
The laceration associated with open calcaneal fractures is often medial, caused by the large internal pressure generated at the time of injury. The mechanism of injury is often one of compression and the medial skin splits at the time of impact. The open injury is an indicator of severe soft tissue trauma and bony injury (Figure 2). Immediate irrigation of the fracture is indicated, however, definitive reduction and fixation are often not possible at the same time. The treating surgeon must decide between an indirect reduction with percutaneous fixation, or delayed open reduction with a more extensile approach. Several studies have demonstrated that the functional outcomes of closed severely comminuted calcaneal fractures are not improved by open reduction and internal fixation. I prefer to manage these fractures with indirect reduction and percutaneous fixation followed by a reconstructive procedure at 18 to 24 months (if indicated).
 Figure 3
Lateral radiograph of a Tongue type Essex-Lopresti calcaneal fracture with significant proximal displacement of the posterior calcaneal tuberosity. The posterior skin was bruised and mottled in appearance. The patient was managed with open reduction and fixation using two 7.0 mm cannulated screws within 78 hours of injury. Full thickness necrosis of the posterior skin occurred and healed in 8 weeks with local wound care – including 4 weeks of VAC therapy. | Avulsions of the posterior calcaneal tuberosity or significantly displaced Essex-Lopresti tongue type fractures can cause necrosis of the posterior skin overlying the fracture fragment (Figure 3). We have recently presented seven patients who developed full thickness necrosis of the posterior skin with this fracture pattern. If the surgeon identifies compromised posterior skin at the time of assessing the fracture, an urgent reduction is required. I often perform a percutaneous reduction using a large Steinman pin placed sagittally through the fragment for leverage and a large reduction forceps to temporarily stabilize the fracture. The posterior tuberosity is then stabilized with two 4.5 or 7.0 mm cannulated screws. Care must be taken to purchase the plantar cortex of the calcaneus with the screws to prevent loss of fixation.
Open Midfoot Fractures
The laceration associated with open midfoot fractures is often dorsal. After appropriate irrigation, the treating surgeon must decide whether to reduce and internally stabilize the fractures at the time, or perform this in a delayed fashion. To date, I have encountered only a few of these fractures, and I have proceeded with immediate open reduction and internal fixation with a combination of K-wires and screws. Delayed closure in 48 hours or skin grafting may be necessary. In severe soft tissue trauma as caused by a lawn mower, free flaps are often required. Proper stabilization of the fracture expedites soft tissue healing. In the presence of severe intra-articular comminution a primary arthrodesis is indicated. It is important to restore proper length of either the medial or lateral column in these circumstances. I have not seen many patients with a history of osteomyelitis following an open midfoot fracture.
The treating surgeon must be cognizant of the severe crush injuries that present as open midfoot fractures; these midfoot injuries are associated with extensive soft tissue injury. In the absence of significant joint subluxation or dislocation, severe crush injuries are best treated with irrigation and an external splint (cast or external fixator). It is not uncommon for patients to develop extensive soft tissue necrosis; at times, they may require an amputation. Regardless of management, these injuries have a poor prognosis.
Open Forefoot Fractures
As with the midfoot, open forefoot fractures can be the consequence of a severe crush injury (e.g., a foot that got run over by a vehicle). There is often extensive soft tissue undermining, and extensive full thickness necrosis is not uncommon. In this circumstance, it is best to let the zone of injury demarcate itself over 10 to 14 days. Afterwards, a treatment plan can be determined.
The most common error in the management of metatarsal fractures occurs when the treating surgeon does not appreciate the importance of an anatomic reduction of the fractured metatarsal bones. After appropriate management of the soft tissue injury, reduction and K-wire fixation of the metatarsal shafts or heads are essential to a good outcome.
Summary
Open fractures of the foot and ankle are rare, poorly classified and variable in their presentation. It is, therefore, difficult to write an extensive review. The treating surgeon must pay attention to the soft tissues and the fractured bone with equal diligence. Given that the majority of open foot and ankle fractures are the result of high-energy trauma, the prognosis is often guarded. |
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