The aim of this prospective study was to evaluate the results of combined lateral sagittal resection osteotomy with subtalar distraction fusion in heels with painful malunion of the os calcis. This case series included 22 patients (23 feet). The mean age of the patients was 37.52 years. Sixteen (69.6%) patients were initially treated conservatively, 5 (21.7%) patients were treated surgically, and 2 (8.7%) patients were missed. The mean time lapsed before surgery was 11.43 months. A wedge of bone was resected to reduce the width of the malunited os calcis and was used as a local graft for subtalar joint fusion and to increase the height of the os calcis. The mean follow-up period was 56.83 ± 6.09 months. According to the scoring system, satisfactory results were found in 18 (82.6%) patients, and 4 (17.4%) patients had unsatisfactory results. Postoperative radiographic assessment revealed an average increase in the heel height of 7.70 ± 1.22 mm and an average decrease in heel width of 8.39 ± 1.47 mm. The average correction in the coronal axis was approximately 8.04° ± 1.26°. Complications included infection and nonunion in 3 (13%) heels. Two heels still had residual varus postoperatively, and 1 patient had injury to the sural nerve. The restoration of heel height, the reduction in heel width, and the primary fracture pattern had a significant relation with the final score. This method is a successful method for the management of subtalar arthritis caused by malunited calcaneal fractures with broadening leading to lateral abutment.