Homologous bone grafting and screw arthrodesis for talus replacement after talectomy: operative technique and results of three cases

Abstract

Fractures of the talus account for approximately 1% of all fractures. Because of the unique circulation, osteonecrosis of the talus is the most morbid complication of talar injuries. In addition, severe infections of the talus are often associated with a complete septic collapse of the talus. Open fractures with defects or significant comminution have an especially bad reputation for reconstructing the talus. It must be the goal to preserve the body of the talus when it can be reasonably reimplanted. A talectomy is the last choice of salvage procedure, but sometimes it is indicated for such severe foot injuries. To maintain the architecture of the foot, a homologous bone graft in combination with screw arthrodesis could be done for talus replacement after soft tissue healing. Technique and results will be reported. At the Department of Traumatology in Braunschweig, Germany, in 1995 three patients (all men, average age 35.3±10.2 years) were treated with cancellous bone graft after talectomy because of infection or complete septic collapse of the talus. In two cases a 3° open total dislocation of the talus occurred. One patient arrived our department after an arthroscopy of the ankle region had been performed at another hospital. In each case a disastrous infection was the outcome. First, in a step-by-step algorithm, an urgent radical debridement with talectomy was performed. To preserve the distance between the tibia and the calcaneus and os naviculare, the bony defect was filled with PMMA-chains, and the external fixator technique was used for immobilization while the infection was treated. After a second- and third-look procedure a free flap was constructed for soft tissue coverage in all cases within the first 10 days. After 17.6 (±3.3) days replacement of the talus was done with homologous cancellous bone graft, combined with double-arthrodesis in two patients, and external fixation was placed for the next 4–5 weeks. In one case a triple-arthrodesis was carried out. At the follow-up after 12 months (range 8–17 months) the bone graft with arthrodesis had become completely ingrown in all cases. No patient was limited in normal activities or required analgesia. A minor leg shortening of less than 1 cm produced no detectable limp and did not necessitate the use of heel-lifts. In the case of severe open fracture of the talus with significant comminution combined with infection and septic bone-collapse a maintenance of the talus is often impossible. The results of this study show that a combination of homologous cancellous bone graft and arthrodesis after talectomy is therefore a good method for minimizing decreased function of the foot. To preserve a maximum of biomechanical function of the foot a double arthrodesis would be the best procedure. In our opinion the Chopart-joint must be left free from arthrodesis to maintain movement of the forefoot. Only in special situations (e.g. when infection involves the distal part of the Chopart-joint) a triple-arthrodesis could be appropriate.