Failure after soft-tissue release with tendon transfer for flexible iatrogenic hallux varus: a systematic review

Hallux valgus is a common forefoot pathology often requiring surgical intervention for symptomatic relief. One complication of hallux valgus correction is flexible hallux varus. Iatrogenic flexible hallux varus often requires surgical repair; however, the most advantageous surgical procedure for repair of iatrogenic flexible hallux varus and their sustainability remains unclear. Therefore, we performed a systematic review to determine the sustainability of soft-tissue release with tendon transfer for the correction of iatrogenic flexible hallux varus. Studies were eligible for inclusion only if they involved failure of soft-tissue release with tendon transfer for flexible iatrogenic hallux varus. Eight studies met our inclusion criteria, seven of which were evidence-based medicine level IV studies and one was level V. A total of 52 patients, all female, involving 68 feet, were included. All studies included soft-tissue release of the first metatarsal-phalangeal joint capsule and 1 of the following procedures: Johnson transfer of the extensor hallucis longus tendon with arthrodesis of the hallux interphalangeal joint (41 feet); Hawkins transfer of the abductor hallucis tendon (9 feet); reverse Hawkins transfer (7 feet); Valtin transfer of the first dorsal interosseous tendon (7 feet); and Myerson transfer of the extensor hallucis brevis tendon (4 feet). The weighted mean age of the patients was 50.4 years, and the weighted mean follow-up was 30.2 months. A total of 11 complications (16.2%) occurred. Of note, only 3 cases (4.4%) of recurrent hallux varus deformity developed, all of which occurred after Johnson transfer of the extensor hallucis longus tendon, with arthrodesis of the hallux interphalangeal joint. Our results support that sustainable correction of iatrogenic flexible hallux varus can be achieved with soft-tissue release of the first metatarsal-phalangeal joint combined with a variety of tendon transfer procedures. However, given the limited data available, potential areas for additional prospective investigation remain.