Results of an Interim Analysis of a Prospective Multicenter Study Assessing Radiographic and Patient Outcomes Following Triplanar Tarsometatarsal Arthrodesis with Early Weightbearing

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: The majority of hallux valgus corrections are performed via a two dimensional approach with 1st metatarsal osteotomy and translation in the transverse plane. This approach has demonstrated high long-term recurrence rates. Recent research demonstrates that 87% of hallux valgus deformities are three-dimensional with abnormal frontal-plane rotation of the metatarsal, which cannot be completely addressed with a two dimensional metatarsal osteotomy alone. While correction at the 1st tarsometatarsal (TMT) joint may provide the optimal surgical approach for 3D anatomic restoration at the apex of the deformity, 1st TMT fusion entails an extended period of non-weightbearing. This study evaluated the clinical, radiographic, and patient-reported outcomes in patients undergoing instrumented triplanar 1st TMT arthrodesis (TMTA) with a biplanar plating system and protected near-immediate weightbearing. Methods: This is a prospective multicenter study that will continue for 60 months post-operatively. Patients between 14-58 years old with symptomatic hallux valgus (intermetatarsal and hallux valgus angles between 10.0-22.0° and 16.0-40.0°, respectively) and no prior hallux valgus surgery on the operative foot are eligible for this study. Patients are treated with an instrumented TMTA procedure using a biplanar plating system with protected near-immediate weightbearing. Several outcomes (radiographic, range of motion (ROM), return to weightbearing and activities, pain measured by visual analog scale (VAS), Manchester-Oxford Foot Questionnaire (MOxFQ), and Patient Reported Outcomes Measurement Information System (PROMIS)) are evaluated post- operatively. Two independent fellowship trained musculoskeletal radiologists reviewed all radiographic data. These interim results are limited to patients completing at least 6 months of follow-up. Results: At time of analysis, 121 patients had undergone TMTA with at least 6 months of follow-up. Mean age was 40.6 (range:15- 58) years, and 91% of patients were female. Mean (SD) days to protected weightbearing in CAM boot, return to work, and return to full work were 8.2 (6.8), 24.0 (29.5), and 51.2 (44.0), respectively. Significant improvements (p