Minimally invasive technique for stage III adult-acquired flatfoot deformity: a mid- to long-term retrospective study.

Purpose: The purpose of this study was to present the functional, radiological, and quality of life outcomes of a series of stage III adult-acquired flatfoot deformity corrections using an original operative approach based on minimal incision surgery (MIS).

Methods: Sixty-two patients (67 feet) with a symptomatic stage III flatfoot deformity were treated using a modified double arthrodesis by MIS. The mean age was 63 years (range, 50 to 81) and the mean follow-up was 6.6 years (range, 3.2 to 11.5). Clinical, radiological, American Orthopaedic Foot and Ankle Society Hindfoot score (AOFAS score), quality of life (SF-36), and satisfaction scores were collected retrospectively.

Results: The mean AOFAS score improved by 54.27 (95% [CI], 57.27-51.3; P < 0.0001), and the SF-36 improved by a mean of 17.5 points (95% CI, 1.4-20.9) in the physical component summary (PCS). Deformity correction was confirmed by a significant improvement in the x-ray measurements (six angles). Bony union was observed in 89.5% of cases (60/67). In all, nine patients (13.4%) needed a secondary surgery: three for talonavicular nonunion, four for progression of the flatfoot deformity, and two for screw protrusion. No cases of superficial infection, wound dehiscence, or avascular necrosis of the talus were observed.

Conclusion: The present series represents the largest study of stage III flatfoot correction using MIS with a mid- to long-term follow-up. Because the data showed clinical and functional improvement after surgery with fewer complications, this technique may be ideal for patients at risk of complications. Graphical abstract.