Subtalar arthroereisis for simultaneous treatment of flexible pes planus during surgical correction of hallux valgus.

Abstract

Background: Scarf osteotomy is a well-established procedure for hallux valgus, yet recurrence rates range from 3.6% to 10%. Pes planus, which often coexisting with hallux valgus, is a risk factor for recurrence. This study aimed to evaluate the effectiveness of simultaneous correction of hallux valgus and flexible pes planus.

Methods: A total of 85 feet with hallux valgus associated with adult flexible pes planus were retrospectively reviewed. All patients were treated with scarf osteotomy (SO). Subtalar arthroereisis using a HyProCure implant (SOH) was performed to correct hindfoot valgus based on shared decision-making. We collected and compared pre- and at least 2 year postoperative clinical outcomes (American Orthopaedic Foot & Ankle Society (AOFAS) forefoot, hindfoot score, Visual Analog Scale (VAS) pain intensity) and radiographic outcomes (hallux valgus angle (HVA), intermetatarsal angle (IMA), Meary's angle, talonavicular coverage angle (TNCA), and calcaneal pitch (CP) angle in both groups.

Results: Of the cases reviewed, 51 feet were allocated to SO group, and 34 feet were in SOH group. Recurrence frequency was 5 feet (9.8%) in the SO group, while no recurrences were reported in the SOH group. There was no significant difference in AOFAS forefoot and VAS scores between the groups, However, the SOH group demonstrated significant improvement in AOFAS hindfoot scores and CP angle, as well as a greater reduction in Meary's angle and TNCA, compared to the SO group. Changes in HVA and IMA did not differ significantly between the groups. Three feet in the SOH group experienced sinus tarsi pain, which resolved after removal of the HyProCure implant.

Conclusions: Subtalar arthroereisis with a HyProCure implant is an effective treatment option for adult flexible pes planus associated with scarf osteotomy for hallux valgus, leading to a steady improvement in the patients forefoot deformity and increased patient satisfaction at least 2 years postoperatively.