Comparative Outcomes Between Step-Cut Lengthening Calcaneal Osteotomy vs Traditional Evans Osteotomy for Stage IIB Adult-Acquired Flatfoot Deformity.

Abstract

The forefoot abduction component of the flexible adult-acquired flatfoot can be addressed with lengthening of the anterior process of the calcaneus. We hypothesized that the step-cut lengthening calcaneal osteotomy (SLCO) would decrease the incidence of nonunion, lead to improvement in clinical outcome scores, and have a faster time to healing compared with the traditional Evans osteotomy. We retrospectively reviewed 111 patients (143 total feet: 65 Evans, 78 SLCO) undergoing stage IIB reconstruction followed clinically for at least 2 years. Preoperative and postoperative radiographs were analyzed for the amount of deformity correction. Computed tomography (CT) was used to analyze osteotomy healing. The Foot and Ankle Outcome Scores (FAOS) and lateral pain surveys were used to assess clinical outcomes. Mann-Whitney U tests were used to assess nonnormally distributed data while χ² and Fisher exact tests were used to analyze categorical variables (α = 0.05 significant). The Evans group used a larger graft size ( P < .001) and returned more often for hardware removal ( P = .038) than the SLCO group. SLCO union occurred at a mean of 8.77 weeks ( P < .001), which was significantly lower compared with the Evans group ( P = .02). The SLCO group also had fewer nonunions ( P = .016). FAOS scores improved equivalently between the 2 groups. Lateral column pain, ability to exercise, and ambulation distance were similar between groups. Following SLCO, patients had faster healing times and fewer nonunions, similar outcomes scores, and equivalent correction of deformity. SLCO is a viable technique for lateral column lengthening. Level III, retrospective cohort study.