Hallux valgus angle as a predictor of recurrence following proximal metatarsal osteotomy.

Background: Postoperative recurrence of hallux valgus is a common complication. We hypothesized that patients who are at higher risk for recurrence of hallux valgus following a proximal metatarsal osteotomy could be recognized preoperatively and at the early follow-up on the basis of their radiographic evaluation. The purpose of this study was to clarify the relationship between the hallux valgus angle, intermetatarsal angle, and recurrence of hallux valgus.

Methods: We performed a case-control study of patients treated with a proximal metatarsal osteotomy for hallux valgus. Dorsoplantar weight-bearing radiographs of 72 feet were assessed preoperatively, at the early follow-up interval (mean 10 weeks), and at the most recent follow-up interval (mean 33 months).

Results: The rate of recurrence was 13.9% (ten feet). Risk factors for recurrence were preoperative hallux valgus angle >40° [odds ratio (OR) = 5.1; 95% confidence interval (CI) 1.3-20.8]. Decreased risks of hallux valgus recurrence were a hallux valgus angle ≤ 15° (OR = 0.036, 95% CI = 0.0056-0.24, p = 0.0005), and an intermetatarsal angle <10° (OR = 0.083, 95% CI = 0.015-0.46, p = 0.0075) at the time of the early follow-up with the numbers available.

Conclusions: Our radiographic results indicated that a preoperative hallux valgus angle >40° can be a risk factor for hallux valgus recurrence. Decreased risk factors for recurrence included hallux valgus angle ≤ 15° and an intermetatarsal angle <10° at the early follow-up. These risk factors may be helpful for modifying surgical procedures, improving surgical outcome, and predicting hallux valgus recurrence.