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

Background: Hallux valgus recurrence is an unsatisfactory complication, with many causes postulated. This study investigated the effect of pes planus on recurrence after scarf osteotomy.

Methods: 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).

Results: Recurrence frequency (HVA greater than 15 degrees) was 27 feet (16%). Hallux valgus recurrence was not influenced by gender (P value = .66) or preoperative IMA (P value = .48). Preoperative HVA greater than 35 degrees was associated with increased frequency of recurrence (P value = .004). Those with T1MA less than -10 degrees demonstrated progression in HVA and deterioration in sesamoid location up to 6 months postoperatively (P 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% (P value <.001). Breaks in T1MA less than -4 degrees were found at the naviculocuneiform joint in 68% of feet in this series.

Conclusions: The prevalence of hallux valgus recurrence correlated with the severity of pes planus. Methods: Level III, retrospective cohort study.