Biomechanical analysis of functional adaptation of metatarsal bones in statically deformed feet.

We analysed the functional adaptation of the first and second metatarsal bones to altered strain in flexible flatfoot. Fifty consecutive women (20-40 years of age) were enrolled: 31 patients with a flexible flatfoot and metatarsalgia (59 feet) and 19 controls with asymptomatic feet (37 feet). They were compared for cortical thickness (medial, lateral, dorsal and plantar) of the two bones. The null hypothesis of no overall difference between the deformed and healthy feet with regard to cortical thicknesses of the two bones was rejected in a multivariate test (p = 0.046). The groups differed significantly only regarding dorsal cortical thickness of the second metatarsal, which was around 18.1% greater in the deformed feet (95% confidence interval: 7.7-28.4%, p < 0.001). Hypertrophy of the dorsal corticalis of the second metatarsal bone appears to be the main metatarsal adaptive reaction to altered strain in the flexible flatfoot.

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.