Proximal Opening-Wedge Osteotomy of the First Metatarsal for Hallux Valgus Using a Low Profile Plate

Abstract

Background: This retrospective study was conducted to evaluate the results of the proximal (basal) opening-wedge osteotomy of the first metatarsal for correction of symptomatic hallux valgus deformity, using a low profile plate. Materials and Method: The procedure was performed by a single surgeon over an 18-month period. Forty-six patients (64 feet) were treated for symptomatic hallux valgus with an average follow up of 20 months. A proximal opening-wedge osteotomy of the first metatarsal and fixation with a low profile plate in combination with a distal soft tissue release with the same postoperative protocol was used in all the patients. Improvement in the hallux valgus angle (HV) and I—II intermetatarsal angle (IM I—II) as well as the AOFAS forefoot score pre and postoperatively (obtained retrospectively from the medical records), were recorded; in particular, the length of the first metatarsal was noted pre- and postoperatively. Results: The HV and IM I—II angles improved by a mean of 14.7 degrees and 6.4 degrees, respectively. The AOFAS forefoot score improved from a mean of 51.3 to 86.8. The mean increase in the length of the first metatarsal was 2.3 mm. Of the more significant complications, five patients developed a hallux varus (early in the series), one of which was symptomatic, and there was one non-union requiring bone graft. Conclusion: The proximal opening wedge osteotomy of the first metatarsal in combination with a distal soft tissue release and stable fixation of the low profile plate was an effective method for correcting a moderate hallux valgus deformity. Guidance provided by the “First Metatarsal Opening Wedge Angle Reference Chart” was found to be helpful for the IM I–II angle correction. Level of Evidence: IV, Retrospective Case Series