Subtalar distraction arthrodesis through a posterior approach

Background: Subtalar arthrodesis is a common procedure for treating subtalar arthrosis. An isolated lateral incision can be used as an approach to subtalar fusion alone. However, it can be a difficult approach for correction of varus or valgus hindfoot deformities through the subtalar joint; especially if it involves distraction to correct calcaneal alignment. Less commonly, two-incision or single-incision medial approaches also have been described, but distraction and angular correction can still be difficult. We present an alternative method, using a posterior Achilles tendon-splitting procedure, that gives excellent subtalar exposure and the ability to obtain distraction with angular correction and bone grafting. Materials and Methods: Six consecutive patients underwent subtalar fusion with a posterior approach. Both varus and valgus deformities secondary to trauma, tendon insufficiency, or congenital deformities were corrected. Distraction was accomplished with laminar spreaders, and fixation was obtained with two 7.3-mm partially threaded cannulated screws. All patients were followed until fusion, and clinical and radiographic results were recorded. No other concomitant procedures were performed. Results: Fusion was observed radiographically in all patients by 3 months postoperatively. No serious wound complications occurred. Correction to slightly valgus alignment (for varus deformity) or neutral alignment (for valgus deformity) was obtained without collapse of autologous bone graft. Talocal-caneal height and all angular measurements were significantly increased (all p < 0.05). Conclusion: The posterior approach for distraction arthrodesis is an alternative to the standard lateral approach technique. It allows safe exposure with the ability to distract while also correcting varus or valgus deformity of the subtalar joint.