Comparative Analysis of First Metatarsophalangeal Arthrodesis: Implant Survival, Failure Modes, and Functional Outcomes across Three Fixation Techniques

PURPOSE OF THE STUDY: First metatarsophalangeal (I. MTP) arthrodesis is a well-established surgical procedure for treating hallux rigidus. Despite its widespread use, the optimal fixation method remains debated. This study compares implant survival, failure modes, and functional outcomes across three fixation techniques: two crossed screws, dorsal plate fixation, and dorsal plate fixation with a lag screw. MATERIAL AND METHODS: A retrospective analysis was conducted on 83 patients (89 fusions) who underwent I. MTP arthrodesis between January 2014 and October 2023. Patients were categorized into three groups based on the fixation method: Group A (two crossed screws, n=31), Group B (dorsal plate, n=29), and Group C (dorsal plate with a lag screw, n=29). Implant survival, failure rates, hardware removal, and clinical outcomes were evaluated using radiographic assessment and the American Orthopedic Foot and Ankle Society-Hallux Metatarsophalangeal Interphalangeal (AOFAS-HMI) scoring system. RESULTS: The overall implant survival rate was 96.54% at one year and 93.98% at ten years. No significant differences in implant survival rates were observed among the three groups. Group C had the highest union rate (93.1%). Asymptomatic pseudoarthrosis was most common in Group B (17.24%). The hardware removal rate was higher in the plate groups (10.34%) compared to the two-screw group (3.1%). The mean AOFAS score was 83.30 (±9.29), with no statistically significant differences between groups. Patient satisfaction was highest in Group C (96.6%) and lowest in Group A (87.1%). CONCLUSIONS: The long-term overall implant survival rate was excellent, with similar survival rates observed across all groups. Functional outcomes, assessed using the AOFAS score, were satisfactory and comparable among the fixation techniques. Hardware removal rates were higher in the groups that utilized plate fixation.