DISTAL CHEVRON OSTEOTOMY WITH LATERAL RELEASE FOR TREATMENT OF HALLUX-VALGUS DEFORMITY

From 1986 to 1990, 42 feet in 30 patients had a combined chevron osteo tomy and lateral release to correct their painful bunion deformity. Se venteen patients, 23 feet, were available for follow-up. The purpose o f this study was to evaluate the outcome of this procedure and to dete rmine the incidence of avascular necrosis. The patients were examined by an independent examiner, radiographs obtained, and questionnaires f illed out. Avascular necrosis was determined using plain films read by a musculoskeletal radiologist who did not know the outcomes. The aver age age was 45 years at the time of the procedure. Average follow-up w as 50 months. The pre-operative intermetatarsal angle averaged 13-degr ees and the hallux valgus angle averaged 31-degrees. At study follow-u p, the intermetatarsal angle averaged 8-degrees and the hallux valgus angle averaged 17.5-degrees. The results were graded by the Mayo Clini c Forefoot Scoring System (75-point scale) and a subjective scoring sy stem. Average postoperative Mayo Clinic score was 67. Fifteen feet wer e subjectively rated as excellent, six as good, and two as fair. Compl ications occurred in four feet. Hallux varus occurred in two feet, ext ension contracture in one foot, and an infection in one foot. None of the feet developed definite radiographic evidence of avascular necrosi s. Distal chevron osteotomy combined with a lateral release for correc tive bunion surgery has come under scrutiny, because of the risk of av ascular necrosis of the first metatarsal head. However, our study show ed no evidence of avascular necrosis on radiographs. In addition, 91% of patients had good to excellent results at an average 50-month follo w-up.