Objective: Metallic implants in the first metatarsophalangeal (MTP) joint have been used for many years in the treatment of hallux rigidus (HR). The HemiCAP(®) prosthesis is the first implant used for resurfacing the metatarsal head in HR treatment. The aim of our study was to evaluate the early results of the HemiCAP(®) prosthesis for the treatment of HR.
Methods: A total of 27 toes of 25 patients with MTP arthritis of the great toe were treated with an Arthrosurface(®)HemiCAP(®) resurfacing implant. The average follow-up time was 37.6 (range: 30 to 43) months. All patients were evaluated clinically and radiographically. Postoperative satisfaction and function were scored according to the American Orthopaedic Foot and Ankle Society (AOFAS) score. Pain was assessed with the use of a visual analogue scale (VAS) ranging from 0 to 10, with 0 indicating the absence of pain and 10 describing the worst pain imaginable.
Results: Mean preoperative AOFAS score improved from 40.94 (range: 25 to 63) to 85.1 (range: 54 to 98) at the final follow-up (p<0.0001). Preoperative average VAS pain scores improved from 8.30 preoperatively to 2.05 at the final follow-up (p<0.0001). The average MTP joint range of motion (ROM) the improved from 14.36 degrees preoperatively to 54.38 degrees at the final follow-up. No radiologic loosening or osteolysis was observed in patients with HemiCAP(®) implant.
Conclusion: The early results of the HemiCAP(®) implant on the metatarsal head are promising. However, studies over a longer period involving more patients would be beneficial in terms of defining and reviewing the stability of the implant and any innovations in the treatment strategy for HR.