Removal rates of subtalar arthroereisis implants in adult flexible planovalgus correction: A case series.

Abstract

Subtalar arthroereisis is used for the surgical correction of flexible planovalgus and in adults is often used as an adjunct to a multi-step procedure. The theorised role of subtalar arthroereisis in adults is to offload the medial soft tissue reconstruction achieved during flexible planovalgus correction to facilitate fibrosis and healing. A common complication is sinus tarsi pain caused by the subtalar implant, with symptoms often only improving upon implant removal. This single-surgeon case series analysed an adult population who underwent surgical correction of flexible planovalgus to identify the rate of subtalar implant removal. Data was collected from local online operating systems and all operations occurred between August 2022 and May 2024. Those who met the inclusion criteria were retrospectively followed up using clinic letters for one year or until discharged if prior to one year of follow-up. Ten patients met the inclusion criteria and the subtalar implant used in all of these was the Arthrex ProStop® arthroereisis screw. The size of implants used were 7 mm, 8 mm or 10 mm. Nine patients did not experience any complications. One patient required subtalar implant removal due to sinus tarsi pain which, upon further investigation, was due to subtalar implant migration. Symptoms resolved upon implant removal. Within the adult population in this case series, there was a subtalar implant removal rate of 10% (95% CI 0.3 - 44.5%; Clopper-Pearson exact) after one year of follow-up. This was based on arthroereisis implant sizes of 10 mm or less. Further large-scale studies are required to verify whether using implants within this size range could obviate the routine removal of the implants in the management of flexible planovalgus in the adult population, unless symptomatic. small sample size; single-surgeon cohort; reporting bias from clinic letters; no validated scoring systems to assess follow-up; short follow-up period.