Hemiarthroplasty for Hallux Rigidus: Mid-Term Results.

Hallux rigidus is a progressive osteoarthritic condition affecting the first metatarsophalangeal joint that causes pain and stiffness, with a marked reduction in dorsiflexion. Joint arthrodesis has previously been the standard treatment of hallux rigidus; however, new surgical techniques have evolved and first metatarsophalangeal joint hemiarthroplasty is now a viable option. The present retrospective study reviewed the data from the 11 patients (12 feet) who had undergone first metatarsophalangeal joint hemiarthroplasty with the HemiCAP(®) prosthesis. Postoperatively, all feet were clinically and radiologically assessed and scored using the hallux metatarsophalangeal-interphalangeal scale developed by the American Orthopaedic Foot and Ankle Society and the Foot and Ankle Disability Index score. Follow-up examinations were performed at a mean of 47 (range 36 to 48) months and showed a mean postoperative American Orthopaedic Foot and Ankle Society score of 66.5 (range 22 to 92) and mean Foot and Ankle Disability Index score of 63.7 (range 26.9 to 98.1). Of the 12 feet, 5 (41.7%) were reported to be pain free at the follow-up examination, 3 (25%) had mild pain, 2 (16.7%) had moderate, and 2 (16.7%) severe pain. Furthermore, 5 feet (42%) displayed no evidence of radiologic subsidence and 7 feet (58%) displayed a mean subsidence of 2.71 (range 1 to 6) mm. Hemiarthroplasty is designed to maintain the joint range of movement and allow easy conversion to arthrodesis, if required. In the present study, most patients continued to have a limited range of movement with only reasonable levels of satisfaction. Most patients continued to experience some level of pain postoperatively. The HemiCAP(®) prosthesis has recently been adapted to include a dorsal flange. This might improve the range of dorsiflexion not seen with the traditional model.