Proximal Supination Osteotomy of the First Metatarsal for Hallux Valgus

Abstract

Background: Risk factors for hallux valgus recurrence include postoperative round-shaped lateral edge of the first metatarsal head and postoperative incomplete reduction of the sesamoids. To prevent the occurrence of such conditions, we developed a proximal supination osteotomy of the first metatarsal. Our aim was to describe this novel technique and report the outcomes in this report. Methods: Sixty-six patients (83 feet) underwent a distal soft tissue procedure combined with a proximal supination osteotomy. After the proximal crescentic osteotomy, the proximal fragment was pushed medially, and the distal fragment was abducted, and then the distal fragment of the first metatarsal was manually supinated. Outcomes were assessed using the American Orthopaedic Foot & Ankle Society (AOFAS) score and radiographic examinations. The average follow-up duration was 34 (range, 25 to 52) months. Results: The mean AOFAS score improved significantly from 58.0 points preoperatively to 93.8 points postoperatively ( P < .0001). The mean hallux valgus and intermetatarsal angle decreased significantly from 38.6 and 18.0 degrees preoperatively to 11.0 and 7.9 degrees postoperatively, respectively (both, P < .0001). Sixty-nine feet (69/83, 83%) had a positive round sign preoperatively, and 66 feet (66/83, 80%) had a negative round sign postoperatively. According to the Hardy’s classification of position of the sesamoids, all feet were classified as grade V or greater preoperatively, and 49 feet (49/83, 59%) were classified as grade IV or less postoperatively. Three feet (3/83, 4%) had recurrence of hallux valgus, defined as a hallux valgus angle ≥ 25 degrees. Conclusion: The rates of occurrence of a positive round sign and incomplete reduction of the sesamoids significantly decreased postoperatively, which may have contributed to the low hallux valgus recurrence rates. We conclude that a proximal supination osteotomy was an effective procedure for correction of hallux valgus and can achieve a low rate of hallux valgus recurrence. Level of Evidence: Level IV, retrospective case series.