Pes Planus Deformity and Its Association With Hallux Valgus Recurrence Following Scarf Osteotomy.

Abstract

Hallux valgus recurrence is an unsatisfactory complication, with many causes postulated. This study investigated the effect of pes planus on recurrence after scarf osteotomy. A total of 183 feet were retrospectively reviewed. All patients were treated with a scarf osteotomy and if required Akin osteotomy. We measured preoperative lateral talus first metatarsal angle (T1MA) to study pes planus; an angle of under -4 degrees was considered pes planus. We measured pre and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), and sesamoid location. In total 164 feet were suitable for inclusion, with follow-up of at least 6 months (10 males and 154 females, mean age: 52 years). Recurrence frequency (HVA greater than 15 degrees) was 27 feet (16%). Hallux valgus recurrence was not influenced by gender (<i>P</i> value = .66) or preoperative IMA (<i>P</i> value = .48). Preoperative HVA greater than 35 degrees was associated with increased frequency of recurrence (<i>P</i> value = .004). Those with T1MA less than -10 degrees demonstrated progression in HVA and deterioration in sesamoid location up to 6 months postoperatively (<i>P</i> value = .038). HVA did not progress beyond 6 months. The prevalence of recurrent hallux valgus with normal T1MA was 1%, in T1MA -4 to -10 degrees it was 29% and in T1MA less than -10 degrees it was 47% (<i>P</i> value <.001). Breaks in T1MA less than -4 degrees were found at the naviculocuneiform joint in 68% of feet in this series. The prevalence of hallux valgus recurrence correlated with the severity of pes planus. Level III, retrospective cohort study.