Tendon transfers for post-operative hallux varus

Purpose of the study latrogenic hallux varus deformity after bunion surgery is a post-operative condition in which the great toe is oriented in medial deviation in relatio n to the first metatarsal head. This overcorrection can be a disabling comp lication with poor cosmetic appearance. A review of the surgical literature showed a reported hallux varus incidence range of 2 p. 100 to 13 p. 100. V arious surgical interventions to treat hallux varus are described in the li terature and we present here our experience in operative management of acqu ired hallux varus based on the results of surgical repair with the Johnson (extensor hallucis longus tendon) EHLT transfer procedure and the Hawkins ( abductor hallucis tendon) procedure in 12 patients. Material and methods All of the patients suffered from painful iatrogenic hallux varus and conse rvative treatment was unsuccessful in all cases. The mean duration of follo w-up was 42 months (range 8-96). The average age was 37 years (range: 17 to 58). The index procedure in eleven patients was a Mc Bride bunionectomy and in o ne case a Petersen procedure. On physical examination, a claw deformity of the hallux characterized by extension of the metatarsophalangeal joint and flexion of the interphalangeal joint was noted in all feet. Eight transfers of the abductor hallucis tendon and four complete transfers of the extensor hallucis longus tendon with interphalangeal joint fusion w ere done. At the time of the final follow-up, patients were interviewed and graded using a standardized questionnaire based on pain, metatarso-phalang eal range of motion, alignment of the hallux, footwear requirements, walkin g capabilities and first ray rest. Results Eleven patients reported satisfactory results and one patient a fair result . Overcorrection was a potential complication and in this retrospective stu dy, one bunion deformity recurred but was asymptomatic. On radiographic evaluation the hallux abductus angle was improved by a mean 26.6 degrees and the average first intermetatarsal angle was 7 degrees (ra nge: 3 degrees to 12 degrees). A narrowing of the metatarso-phalangeal join t was observed in four cases (2 Johnson and 2 Hawkins). Discussion The addition of a tendon transfer to the medial soft tissue release is reco mmanded in most cases of hallux varus in active patients without osteoarthr itis of the metatarso-phalangeal joint. Our experience with the EHLT transf er or the abductor hallucis tendon transfer demonstrated excellent correcti on of the hallux varus deformity; however metatarsophalangeal joint stiffne ss was frequently observed. As originally described by Johnson et Spiegl, the entire extensor hallucis longus tendon was used in conjunction with an interphalangeal joint arthrod esis in the presence of a fixed and painful deformity of the hallux interph alangeal joint. If no fixed claw deformity was present an abductor hallucis tendon transfer was preferred. Onset of degenerative disease involving the metatarso-phalangeal joint in f our cases may jeopardize long term survival of these surgical results.