[Dynamia correction of hallux valgus deformity with musculus extensor hallucis longus shifting].

OBJECTIVE: To discuss the mechanisms and clinical effect of musculus extensor hallucis longus shifting in correcting hallux valgus (HV) deformity.

METHODS: From April 2004 to December 2006, 25 cases of HV (38 feet) were treated by musculus extensor hallucis longus shifting. There were 2 men and 23 women, aging from 22-60 years (mean 46.3 years). HV angle was 21-45 degrees (mean 31.30 degrees), intermetatarsal (IM) angle was 7-21 degrees (mean 12.52 degrees). The HV were corrected by cutting osteophyma of the first metatarsal bone, cutting transverse head of adductor pollicis, transferring musculus extensor hallucis longus and reconstructing its insertion.

RESULTS: The patients were followed up 6-14 months after operation. HV angle and IM angle were 7.30 degrees +/- 2.62 degrees and 6.50 degrees +/- 2.46 degrees respectively, showing significant differences when compared with before operation (P < 0.05). According to the American Orthopaedic Foot & Ankle Society (AOFAS) score system, the foot function was excellent in 25 feet, good in 7 feet and poor in 6 feet, and the excellent and good rate was 84.2%. Hallux varus occurred in 2 feet after 2 months of operation, metatarsophalangeal joint limitation of motion in 2 feet after 3 months of operation, no HV recurred.

CONCLUSION: The HV deforemity can be corrected by shifting the musculus extensor hallucis longus and reconstructing its insertion. It makes stress of metatarsophalangeal joint balance and prevent recurrance of HV deformity.