Radiographic Outcomes of Cotton Osteotomy in Treatment of Adult-Acquired Flatfoot Deformity

Abstract

Background: We investigated the long-term radiographic outcomes of the Cotton osteotomy performed at our institution by the 2 senior authors in conjunction with other reconstruction procedures to correct adult-acquired flatfoot deformity (AAFD). Methods: We retrospectively studied patients who underwent Cotton osteotomy between 2005 and 2010 with minimum 4-year follow-up. Radiographic assessment was made on weightbearing radiographs taken at 4 different time intervals: preoperative, early (first postoperative full weightbearing), intermediate (between 1 and 4 years postoperatively), and final (over 4 years postoperatively). Results: Nineteen patients were included. Final follow-up was 8.6 ± 2.6 years. The lateral talus–first metatarsal angle improved significantly from preoperative to early radiographs (n = 15; mean change: 30 degrees, 95% CI, 21.6-38.7; P < .0001). A significant loss of correction was observed between intermediate and final radiographs (n = 11; mean change: 17 degrees, 95% CI, 8.1-26.4; P < .0001). Of 14 patients with early radiographs, 8 lost >50% of the correction initially achieved. Medial column height decreased by 3.0 mm (95% CI, 1.80-7.90; P = .35) between early radiographs and final follow-up. Discussion: This is the longest reported radiographic follow-up of the Cotton osteotomy performed to address forefoot varus deformity as part of AAFD. The Cotton osteotomy achieved radiographic correction of the medial longitudinal arch at early follow-up, but approximately half of the patients had lost over 50% of that correction at final follow-up. The lengthened angular shape of the cuneiform did not collapse, implying that further collapse occurred through the medial column joints. Level of Evidence: Level IV, case series.