Horisberger M Haeni D Henninger HB Valderrabano V Barg A 2016 BACKGROUND The current gold standard in the treatment of severe hallux rigidus is arthrodesis of the first metatarsophalangeal (MTP-I) joint. We present the results of a new 3-component MTP-I prosthesis. We determined (1) the intraoperative and perioperative complications; (2) survivorship of prosthesis components and rate of secondary surgeries for any reason; (3) prosthetic component stability and radiographic alignment; (4) the degree of pain relief; and (5) the midterm functional outcomes including radiographic range of motion (ROM). METHODS From 2008 to 2010, we prospectively included 29 MTP-I prostheses in 25 patients. The average age of the patients was 63.1 years (range, 48-87 years). The average follow-up was 49.5 months (range, 36-62 months). We observed complications and reoperations. A visual analog scale for pain and the American Orthopaedic Foot & Ankle Society (AOFAS) forefoot score were obtained pre- and postoperation. Component stability and alignment were assessed using weight-bearing radiographs. Fluoroscopy was used to determine radiographic MTP-I ROM. RESULTS Seven (24.1%) patients underwent 1 or more secondary surgeries. Four cases (13.7%) eventually had a conversion to MTP-I arthrodesis. Two patients (3 cases) died from causes not related to the procedure. This left 22 feet in 19 patients for final follow-up. All but 3 remaining prostheses showed stable osteointegration and no migration, but MTP-I alignment showed high variability. The average pain score decreased from 5.9 (range, 3-9) to 1.2 (range, 0-5). The average AOFAS forefoot score increased from 55 (range, 0-80) to 83.5 (range, 58-95). Range of motion initially increased from 37.8 degrees (range, 0-60 degrees) to 88.6 degrees (range, 45-125 degrees) intraoperatively and decreased to 29.0 degrees (range, 11-52 degrees) at latest follow-up. CONCLUSION Our data suggest that total arthroplasty of MTP-I leads to a high amount of revision surgeries, but the remaining patients had significant pain relief at midterm follow-up. However, we observed high variability regarding the prosthesis component alignment and poor range of motion. LEVEL OF EVIDENCE Level IV, prospective cohort study. https://sonar.ch/global/documents/202069 eng info:eu-repo/semantics/altIdentifier/doi/10.1177/1071100716637901 info:eu-repo/semantics/altIdentifier/pmid/26979844 Foot & ankle international. - 2016 hallux rigidus metatarsophalangeal joint prosthesis Arthroplasty, Replacement Hallux Hallux Rigidus Humans Joint Prosthesis Metatarsophalangeal Joint Pain Measurement Patient Satisfaction Prospective Studies Radiography Range of Motion, Articular Weight-Bearing Total Arthroplasty of the Metatarsophalangeal Joint of the Hallux. http://purl.org/coar/resource_type/c_6501