Treatment of Symptomatic Bunionette Deformity with Distal Metatarsal Metaphyseal Osteotomy with no Fixation or Strapping

Abstract

Category: Lesser Toes; Bunion Introduction/ Purpose: Bunionette deformity (BD) is a painful condition of the fifth metatarsal characterized by an osseous prominence and varus deformity. The purpose of this study is to assess the clinical, functional, and radiographic outcomes of percutaneous distal metatarsal metaphyseal osteotomy (DMMO) without fixation or post-operative strapping of the foot. Methods: A retrospective case series was performed on 111 patients (132 feet) with symptomatic BD who underwent percutaneous DMMO of the fifth metatarsal from September 2020 to January 2022. Patient-reported clinical outcome measures, including the Foot Function Index (FFI) questionnaire, the Visual Analog Score (VAS), and overall satisfaction were collected. Four- Five intermetatarsal angle (IMA) correction, time to bone union, and complication rates were assessed in all patients. Results: The mean post-operative follow-up time was 24.1 months. Both radiographic parameters and patient-reported outcome measures significantly improved after DMMO procedure. The average fourth-to-fifth IMA improved from 12.2 degrees, preoperatively, to 4.4 degrees, postoperatively (p <.001). Pre-operatively, patients had a mean VAS of 7.6, which improved to 0.6 at the last follow-up (p <.001). Furthermore, The average FFI significantly decreased from 19.2 to 4.4 (p <.001). 108 out of 111 patients reported being satisfied with the outcomes of the procedure. Average bone union was achieved at 12.6 weeks post- operation, with a minimum of 12 and a maximum of 25 weeks. The complication rate was 1.5%, including one case of an asymptomatic cock-up deformity and one case of lateral fifth metatarsal shaft bone overhang pain, which resolved with an exostectomy. Conclusion: The results of this study suggest that percutaneous DMMO of the fifth metatarsal without internal fixation or postoperative immobilization or strapping is effective at improving radiographic alignment, pain, function, and overall satisfaction with minimal complication.