Symptomatic talocalcaneal coalition resection: indications and results.

We report our results of talocalcaneal coalition (TCC) resection in 25 feet after failed nonoperative treatment. Preoperative computed tomography (CT) scans were used to quantify the amount of heel valgus and the size of the coalition relative to the posterior facet. The ratio of mean TCC cross-sectional area to the surface area of the posterior facet was 53.4%. Mean hindfoot valgus was 17.8 degrees. The mean AOFAS (American Orthopaedic Foot and Ankle Society) hindfoot score was 81.9, at an average of 2.5 years after surgery. Statistical analysis determined a significant association between TCC > 50% the size of the posterior facet and poor outcome (p = 0.014). Similarly, heel valgus > 21 degrees was associated with poor outcome (p = 0.014). However, there were good postoperative results in feet with heel valgus > 21 degrees and in those whose TCC was > 50% of the posterior facet. Therefore we advocate using these CT-scan criteria for preoperative discussions with patients and families and not for determination of the index operative procedure (resection vs. arthrodesis). Hindfoot arthrodesis should only be used as a salvage procedure. We recommend those feet with heel valgus > 21 degrees use an orthosis postoperatively to stabilize the hindfoot or a secondary calcaneal procedure should nonoperative management fail.