Surgical treatment of hyperpronation using an extraosseous talotarsal stabilization device: radiographic outcomes in 70 adult patients.

The purpose of this study was to determine radiographic correction achieved in adult patients treated with an extraosseous talotarsal stabilization (EOTTS) procedure. Patients diagnosed with flexible/reducible talotarsal joint dislocation (partial) underwent surgical correction with the HyProCure(®) EOTTS device. Preoperative and postoperative weightbearing radiographs taken in the anteroposterior (AP) and lateral views for a total 95 feet (in 70 patients) were analyzed to determine standardized radiographic angles, and to quantify the correction obtained after the EOTTS procedure. Postoperative radiographs were taken at an average follow-up of 17 days from the surgery date. The mean preoperative and postoperative talar second metatarsal angles (measured from the AP radiographs) were 24.8° ± 1.0° and 5.8° ± 0.9°, respectively, that is, mean decrease by 19°. The mean preoperative and postoperative talar declination angles (measured from the lateral radiographs) were 25.1° ± 0.7° and 19.4° ± 0.5°, respectively, that is, mean decrease by 5.7°. The mean preoperative and postoperative calcaneal inclination angles (measured from the lateral radiographs) were 21° ± 0.7° and 21.8° ± 0.7°, respectively, that is, mean increase by 0.8°. Postoperatively, the talar second metatarsal and talar declination angles were reduced to average values reported in the literature for normal feet. This study shows the efficacy of a minimally invasive EOTTS procedure in restoring the normal angular relationships between hindfoot and forefoot osseous structures on weightbearing, in both the transverse and sagittal planes. This indicates stabilization of the talotarsal joint complex and elimination of hyperpronation, which may lead to reduced pain, improved foot functional abilities, and patient satisfaction.