Minimally Invasive Distal Metatarsal Metaphyseal Osteotomy (DMMO) of the Fifth Metatarsal for Bunionette Correction.

BACKGROUND: Different osteotomies have been proposed for the treatment of bunionette deformity. Minimally invasive surgery is now increasingly popular for a variety of forefoot conditions. The aim of this study was to evaluate the outcome following fifth minimally invasive distal metatarsal metaphyseal osteotomy (DMMO) for bunionette deformity.

METHODS: Nineteen patients (21 feet) who had symptomatic bunionette deformity and failed conservative treatment between 2014 and 2016 were included in this retrospective study. Clinical data were recorded, and pre- and postoperative Manchester-Oxford Foot Questionnaire (MOXFQ) scores and visual analog scale (VAS) pain score were collected. The mean follow-up was 28 months (range, 12-47).

RESULTS: The mean MOXFQ summary index score decreased from 71 (range, 59-81) preoperatively to 10 (range, 0-30) postoperatively. All 3 MOXFQ domains also improved. The average improvement in VAS score was 7. Forefoot swelling and some painful symptoms took an average of 3 months to settle. There were no wound or nerve complications. One patient required a dorsal cheilectomy for a symptomatic prominent dorsolateral callus formation.

CONCLUSION: The minimally invasive fifth DMMO for bunionette deformity was a safe and effective technique. It had relatively few complications and led to good clinical results. We believe it is important to warn patients that the forefoot swelling will take months to settle compared to an osteotomy with fixation, and there is a 10% chance of a prominent callus over the osteotomy site.

LEVEL OF EVIDENCE: Level IV, retrospective case series.