Arthroscopic subtalar arthrodesis through the two portal sinus tarsi approach: a series of 77 cases

R. Walter, M. Butler, S. Parsons

Introduction: Traditional open approaches for subtalar arthrodesis have reported nonunion rates of 5-16% and significant incidence of infection and nerve injury. The rationale for arthroscopic arthrodesis is to limit dissection of the soft tissues in order to preserve blood supply for successful fusion, whilst minimising the risk of soft tissue complications. The aim of this study was to determine the outcomes of sinus tarsi portal subtalar arthrodesis.

Methods: Case records of all patients undergoing isolated arthroscopic subtalar arthrodesis by two senior surgeons between 2004 and 2014 were examined. All patients were followed up until successful union or revision surgery. The primary outcome measure was successful clinical and radiographic union. Secondary outcome measures included occurrence of infection and nerve injury.

Results: Seventy-seven procedures were performed in 74 patients, with successful fusion in 75 (97.4%). One (1.3%) superficial wound infection and one (1.3%) transient sural nerve paraesthesia occurred. Fixation with a single screw provided sufficient stability for successful arthrodesis.

Conclusions: To our knowledge this is the largest reported series of isolated arthroscopic subtalar arthrodeses to date, and the first series reporting results of the two portal sinus tarsi approach. This approach allows access for decortication of all three articular facets, and obviates the need for a posterolateral portal, features which may explain the high union rate and low incidence of sural nerve injury in our series.