Avoidance of injury to the posterior neurovascular bundle during total ankle arthroplasty - A simple technical tip.

Iatrogenic nerve injury to the tibial nerve is a serious but avoidable complication of total ankle replacements and may be under-reported as it may go unrecognised or thought to be due to tarsal tunnel syndrome. The tibial nerve is particularly vulnerable during the saw cuts at the posteromedial corner without appropriate protection. Prior to drilling the tibial and talar pins of the adjustment block for the Infinity ankle replacement we perform a 2 cm incision behind the medial malleolus. The tibialis posterior tendon sheath is identified and incised. A periosteal elevator is used to develop a plane between the back of the tibia and the tibialis posterior tendon and then exchanged for a mini Hohmann retractor protecting the neurovascular bundle. This allows us to drill the pins and saw cuts safely. The Hohmann retractor can be felt at the tip of the saw blade providing reassurance that the blade is not too deep. Our technique has not previously been reported in the literature. It acts as a simple reproducible way of avoiding injury to structures at the back of the ankle joint.