[Modified Chevron osteotomy in the treatment of moderate and severe hallux valgus].

Objective: To investigate the method and clinical effect of modified Chevron osteotomy of the distal end of the first metatarsal in the treatment of moderate and severe hallux valgus.

Methods: From January 2015 to January 2019, 28 patients(30 feet) with moderate and severe hallux valgus were treated with modified Chevron osteotomy combined with lateral soft tissue release of the first metatarsophalangeal joint, including 2 males (2 feet) and 26 females (28 feet). The age ranged from 35 to 74 (57.3±9.3) years;10 feet on the left, 16 feet on the right, 2 cases on both sides(4 feet);the course of disease was 3 to 12 (9.32±3.89) years. The changes of hallux valgus angle(HVA), intermetatarsal angle(IMA) between the first and second metatarsals and distal metatarsal articular angle(DMAA) of the first metatarsal were measured and compared before and 6 months after operation. The American Orthopaedic Foot and Ankle Society(AOFAS) thumb joint scoring system was used to evaluate the curative effect.

Results: All 28 patients were followed up for 8 to 16 (11.28±3.42) months. The incision healed well in all patients, and there were no complications such as incision infection and metatarsal head necrosis. The healing time of osteotomy site was 6 to 10(7.12±1.34) weeks. Preoperative HVA, IMA, DMAA and AOFAS were (36.06±6.02) °, (21.78±4.16) °, (8.21±2.65) ° and (52.90±10.97) respectively, at six months after operation, they were (8.87±2.46) °, (11.66±2.84) °, (3.65±1.00) ° and (87.45±10.55) respectively, there was significant difference between preoperative and 6 months after operation(<0.05). At 6 months after operation, AOFAS score was excellent in 20 feet, good in 7 feet and poor in 3 feet. Among the 3 patients with poor scores, 2 were excellent after revision, and 1 was significantly improved after using custom insoles.

Conclusion: Modified Chevron can effectively correct HVA, IMA and DMAA and improve functional recovery. The modified Chevron osteotomy increases the moving distance and the contact of the osteotomy surface. It can be fixed with multiple screws, has strong correction ability, and can exercise early. It is one of the optional methods for the treatment of moderate and severe hallux valgus.