Radiographic Analysis and Clinical Efficacy of Hindfoot Arthrodesis With Versus Without Cotton Osteotomy in Stage III Adult Acquired Flatfoot Deformity.

Forefoot varus develops as a result of longstanding adult-acquired flatfoot deformity (AAFD). This occurs with varying degrees of deformity and flexibility. Residual forefoot varus following hindfoot realignment in AAFD can lead to lateral column loading and a persistent pronatory moment in efforts to reestablish contact between the forefoot and the ground. The Cotton osteotomy may serve as a reasonable adjunct procedure to help avoid complications and poor outcomes associated with residual forefoot varus in patients undergoing hindfoot arthrodesis for stage III AAFD. The aim of this study was to compare the radiographic outcomes in patients undergoing isolated hindfoot arthrodesis to patients undergoing hindfoot arthrodesis with adjunctive cotton osteotomy. We retrospectively reviewed 47 patients matched based upon age, sex, and comorbidities who underwent hindfoot reconstruction for the treatment of stage III AAFD between 2015 and 2019. A retrospective radiographic review was performed on standard weightbearing radiographs including anterior-posterior and lateral views preoperatively, postoperatively at the initiation of full weightbearing, and at final follow-up. Statistical analysis utilizing paired t test to calculate p values where <.05 was statistically significant. At final follow-up, radiographic measurements showed statistically significant differences in CAA, calcaneal inclination, talo-calcaneal, and talar tilt (p value <.05). The Cotton osteotomy group showed a quicker return to presurgical activity level and a decreased incident of tibiotalar valgus. Our study suggests that the Cotton osteotomy can address residual forefoot varus and potentially prevent further progression of ankle valgus in AAFD when used in combination with hindfoot arthrodesis.