Radiographic Forefoot Width Following Minimally Invasive Chevron Akin Bunionectomy

Abstract

Background: Hallux valgus (HV) is a common cause of pain and deformity of the forefoot. Minimally invasive chevron Akin (MICA) bunionectomy is a method for HV correction associated with less pain and swelling, with early return to weightbearing in a regular shoe. The purpose of this study was to determine how the MICA procedure affects forefoot width. Methods: Twenty-eight patients (26 female, 2 male; 9 left, 19 right) at a single institution who underwent primary MICA for HV correction by 3 treating surgeons were retrospectively reviewed. Pre- and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), bony forefoot width, and soft tissue forefoot width were measured by 2 independent observers. Radiographic measurements were calibrated using fifth metatarsal length. Wilcoxon signed rank test compared changes in HVA, IMA, DMAA, and forefoot widths. Pearson correlation coefficient evaluated association between HVA, IMA, DMAA, and changes in forefoot width. Results: At mean follow-up of 5.4 (range 3-13.7) months, bony forefoot width decreased significantly by 3.7 mm (4%, P < .001) and soft tissue forefoot width decreased by 2.5 mm (2%, P < .01). Decrease in HVA was moderately correlated with change in bony forefoot width ( r = .38, P < .05) and change in soft tissue forefoot width ( r = .45, P < .05). Decrease in IMA was moderately correlated with change in bony forefoot width ( r = .45, P < .05) and change in soft tissue forefoot width ( r = .44, P < .05). Conclusion: The MICA procedure resulted in modest, yet significant, decrease in both bony and soft tissue forefoot width. Decrease in HVA and IMA demonstrated moderate correlation with changes in forefoot width. Patients can be counseled on these changes leading up to, and after, MICA bunionectomy surgery. Level of Evidence: Level III, retrospective comparative series.