Isolated Talonavicular Arthrodesis as Treatment for Flexible Progressive Collapsing Foot Deformity: A Case Series

Abstract

Background: For the younger, more active patient with flexible symptomatic progressive collapsing foot deformity (PCFD), joint-sparing procedures may be preferred to preserve functional motion. Isolated talonavicular (TN) arthrodesis has been described for treatment of rigid and flexible PCFD for patients that are older and less active whose deformity is still correctable through the TN joint. The purpose of this study was to evaluate radiographic and clinical outcomes in patients with PCFD treated with isolated triplanar correction with a TN joint arthrodesis. Methods: Forty-nine patients (53 feet) with flexible PCFD underwent isolated TN arthrodesis. Weightbearing radiographs were performed pre- and postoperatively, and measurements included lateral talar–first metatarsal angle, calcaneal pitch, TN coverage angle, and the anteroposterior (AP) talar–first metatarsal angle. The Foot and Ankle Ability Measure (FAAM) and Veterans-Rand 12-Item Health Survey (VR-12) scores were also collected. Results: Thirty-five females and 14 males were evaluated with a mean age of 63 years, at an average follow-up of 41.3 months. Significant improvements were found radiographically. Lateral radiographs demonstrated improvements in lateral talar–first metatarsal angle from 25.2 degrees preoperatively to 9.5 degrees postoperatively ( P < .001) and calcaneal pitch from 14.9 degrees preoperatively to 17.5 degrees postoperatively ( P < .001). AP radiographs showed the TN coverage angle improving from 35.0 degrees to 4.9 degrees postoperatively ( P  < .001) and AP talar–first metatarsal angle improving from 17.3 degrees to 5.9 degrees postoperatively ( P < .001). Clinical outcomes were improved in the FAAM pain score (48.6 to 39.2, P = .130), FAAM ADL score (53.8 to 69.2, P = .002), FAAM Sport score (29.5 to 40.7, P = .099), and the overall FAAM score (47.7 to 63.1, P = .006). Patient satisfaction with medical care was 85.2/100 postoperatively. Conclusion: Isolated TN arthrodesis is a viable surgical option for older, lower-demand patients with flexible PCFD. This study demonstrated significant improvements in radiographic alignment and FAAM scores. Comparative studies with other surgical procedures should be performed to determine which is the best technique for older, lower-demand patients with flexible PCFD. Level of Evidence: Level III, retrospective cohort study.