Preliminary findings using subtalar arthroereisis as adjunct treatment for correction of flexible flatfoot: short-term radiographic results

Abstract

Objective: Recent reports suggest that subtalar arthroereisis may be effective as one component of surgical reconstruction for adult acquired flexible flatfoot. This study assessed short-term radiographic outcomes with standard reconstruction with adjuvant arthroereisis and determined whether arthroereisis introduced any undesirable effect. Methods: Twenty-seven patients with adult acquired flatfoot were treated with a subtalar implant with other corrective procedures, including tendon transfer, calcaneal osteotomy, and/or heel cord lengthening by one surgeon. Pre and postoperative weight bearing radiographs at six months and one year were compared for angular measurements, subtalar arthritis and peri-implant lucency. Sinus tarsi space was measured. Statistical analysis was done with one-way of analysis of variance (ANOVA) with post hoc analysis and chi-square analysis. Results: The difference in talonavicular uncoverage angle and sinus tarsi space was significant between preoperative and 6-month and preoperative and 12-month values (p=0.03 and p=0.05, respectively). Of the 27 implants, ten were removed, at an average of 7.7 months (range, four to 12). Conclusions: This retrospective evaluation showed that radiographic correction of flatfoot deformity was achieved at one year follow-up with a standard surgical protocol that incorporates the adjuvant use of subtalar arthroereisis. The removal rate was relatively high, but subtalar arthroereisis did not appear to be associated with adverse consequences. The long-term effect of implant removal on correction cannot be established in this preliminary study and will be reported after longer follow-up.