LONG-TERM RESULTS WITH MITCHELL’S OSTEOTOMY APPLIED FOR HALLUX VALGUS (HV)

Abstract

Introduction: Mitchell’s operation is a double step-cut osteotomy through the neck of first metatarsal (MT) which displaces laterally and plantar flexes the metatarsal head and minimally shortens the first MT. In coexisted further forefoot abnormalities this osteotomy can be combined by additional corrective osteotomies of the rest metatarsals and straightening of toes.

Material and Methods: A prospective study was carried out in our Department, on 42 patients (51feet) operated with this osteotomy alone or combined.

The mean follow-up time was 10 years (range, 3–15 years). The average age of patients was 58 years. The average angle of HV deformity was 38 degrees (in nine feet this angle was more than 40 degrees). Mean inter-metatarsal (IM) angulation was 15 degrees.

The procedure was always followed by Y or V capsuloplasty of first metatarsophallangeal (MTP) joint. Moderate arthritis of first MTP joint was not considered by us as a contraindication for this operation. The osteotomy was secured by two crossed K-wires.

In 20 feet (15 patients) with coexisted forefoot abnormalities oblique osteotomies of the rest metatarsals, arthrodeses of proximal interphalangeal (PIP) joints and elongation of extensor tendons were carried out.

Results: In examination, we checked the correction of the deformities; we assessed pain and comfortability in wearing shoes and the joints motion, hi early postoperative examination the mean correction in HV angle was 18 degrees and in IM angle was 5 degrees, but in last examination there was a loss of 5 degrees in the HV angle correction. One hallux was overcorrected. 90% of the results were satisfactory including all feet with osteoarmritis of first MTP joint. 10% of the results considered as poor including all feet with preoperative HV deformity of more than 40 degrees. Ten feet (eight patients) suffered from metatarsalgia established because of fall of MT arch. We feel that Mitchell’s osteotomy is not suitable for HV deformity exceeding the 40 degrees.