Fracturing the Lateral Hinge Improves Radiographic Alignment and Does Not Affect Clinical Outcomes of the Minimally Invasive Akin Osteotomy

Abstract

Background: Intraoperative fracture of the lateral cortex is common during Akin osteotomy. In a recent study, lateral cortex fracture did not impede healing or result in loss of correction in a combined cohort of open and percutaneous osteotomies stabilized by K-wire fixation. We hypothesize that undesired lateral cortex fracture will not affect radiographic correction and patient-reported outcomes in a percutaneous cohort stabilized by permanent, rigid screw fixation. Methods: Consecutive patients with hallux valgus who underwent first metatarsal osteotomy and percutaneous Akin osteotomy stabilized by permanent, rigid screw fixation between May 2020 and January 2022 were retrospectively reviewed. Patients were stratified based on fractured lateral cortex (FC) or its absence (nonfractured cortex [NFC]). Visual analog scale (VAS) and Foot Function Index (FFI) were used to assess pain and patient-reported outcomes at 1-year follow-up. Patients were polled for satisfaction at 1-year follow-up by yes/no survey. Results: Ninety-eight patients (89% female) were reviewed (98 feet; 43 NFC, 55 FC). Mean age was 48.3 years (range, 18-83 years). Mean preoperative VAS score was 7.5 and 7.7 in NFC and FC groups, which significantly decreased to 0.6 ( P < .01) and 0.6 ( P < .01), respectively. Mean total FFI was 53.9 and 54.2 and decreased to 17.9 ( P < .01) and 17.2 ( P < .01) in the NFC group and FC group, respectively. Overall, 97.8% of the NFC group and 96.4% of the FC group reported satisfaction. Mean HVA improved from 27.2 (16-42) degrees to 10.7 degrees (4-12) postoperatively in the NFC group. And in the FC group, HVA improved from 29.3 (19-39) degrees to 7.1 (4-12) degrees postoperatively. Postoperative HVA was significantly lower in the FC group ( P < .05). Conclusion: In an exclusively percutaneous surgical cohort with correction maintained by rigid screw fixation, fracture of the lateral cortex is associated with improved postoperative radiologic alignment without detriment to patient-reported outcomes. Level of Evidence: Level III, retrospective cohort study.