Subtalar distraction arthrodesis using fresh-frozen allogeneic femoral head augmented with local autograft

Background: Tricortical autograft has been commonly used in subtalar distraction arthrodesis (SDA) for severe calcaneal malunion. Structural allograft enriched with orthobiological agents is an alternative. This study was performed to evaluate the results of SDA using fresh-frozen allogeneic femoral head without the addition of orthobiological agents. Materials and Methods: We retrospectively reviewed 15 consecutive SDA procedures (13 patients) with allogeneic femoral head augmented with local autograft for the treatment of severe calcaneal malunion. Clinical outcome was evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, visual analog scale (VAS) pain score, Short Form-12 (SF-12), range of motion (ROM) of the ankle joint, and patient satisfaction rate. Radiographic assessment included the talar declination angle (TDA), calcaneal inclination angle (CIA), lateral talocalcaneal angle (LTCA), heel height, calcaneal length, and union time. Results: At a median follow-up of 36.0 months (range, 24-47 months), all 15 feet (100%) achieved union, at a median of 13.0 weeks (range, 12-18 weeks). The AOFAS score and VAS pain score improved significantly, with a satisfaction rate of 93.3%. The TDA, CIA, LTCA, and heel height improved significantly. The median increase in heel height was 8.6 mm (range, 1.9-20.1 mm). There was a significant reduction in calcaneal length. Complications included 1 varus malalignment, 1 complex regional pain syndrome, 1 hardware irritation, and 1 sural neuralgia. Conclusion: This study found that SDA using fresh-frozen femoral head allograft without an orthobiological agent was cost-effective and may have outcomes comparable to those using autograft or allograft enriched with orthobiological agents. Level of Evidence: Level IV, retrospective case series.