Mitchell and Wilson metatarsal osteotomies for the treatment of hallux valgus: comparison of outcomes two decades after the surgery.
BACKGROUND: At short-term followup, the Mitchell osteotomy appears to provide more symptomatic improvement than the Wilson osteotomy. We compared the outcomes of the two procedures two decades after the surgeries. METHODS: In a two-center retrospective study, 30 patients (35 feet) who had Mitchell osteotomies and 28 patients (35 feet) who had Wilson osteotomies were evaluated 20 to 22 years after surgery for correction of the hallux valgus angle (HVA) and intermetatarsal (IMA) angle, changes in the shortening of the first metatarsal and improvement in the overall status (a composite radiographic and clinical outcome according to Bonney and McNab). RESULTS: With adjustment for the preoperative values and surgical center (analysis of covariance), the HVA (degrees) had a higher correction in the Mitchell group (p = 0.075), while IMA was comparably corrected by the two methods. Shortening of the first metatarsal was greater in the Wilson group (Mitchell-Wilson = -1.93, 95% CI -2.69 to -1.17, p < 0.001). Before the surgery, overall status was graded "poor" or "good" in all feet (28/7 Mitchell, 29/6 Wilson). After the surgery, the status was graded "excellent" or "good" (29/6) in the Mitchell group, and "excellent," "good" or "poor" (25/7/3) in the Wilson group. The status was improved by at least one grade-level in all 35 feet in the Mitchell group and in 31 of 35 feet in the Wilson group. With stratification for the preoperative status, the proportion of "improvements" was higher in the Mitchell group (Mitchell-Wilson = 11.1%, 95% CI 0.7 to 21.5%, p = 0.036). In an alternative analysis (logistic regression), with adjustment for the preoperative status, center, and IMA values, the Mitchell method also appeared superior in this outcome (likelihood ratio test p = 0.021). CONCLUSIONS: As assessed 20 to 22 years after the surgery, the Mitchell osteotomy resulted in less shortening of the first metatarsal in a somewhat greater proportion of feet with an improved overall status than the Wilson method.