1ST METATARSAL HEAD RESURFACING IN THE TREATMENT OF HALLUX RIGIDUS; A BRITISH PERSPECTIVE

Abstract

Introduction: Hallux Rigidus(HR) is a progressive arthritic process of the first MTP joint that causes pain, stiffness and uncomfortable enlargement of the joint, thus resulting in significant morbidity.

Current treatment options include cheilectomy, resection arthroplasty, distal osteotomies (eg Moberg) or arthrodesis (Gold standard). Resurfacing of the metatarsal head, and concurrent joint release allow successful treatment of all stages of Hallux Rigidus, also offering the advantages of maintenance of metatarsal length, and movement.

Method: Patients with stage II-IV hallux rigidus, who had failed conservative management, had good bone stock, no previous signs of osteomyelitis and neurovascularly intact status were offered this new procedure. All procedures were performed by the senior author, in a single centre. The HemiCap^® MTP prosthesis was implanted using a dorsal approach to the 1st MTPJ. The joint was decompressed and dorsal / lateral bone shaping performed to maximise movement. Pre op and post op scoring at 6 weeks, 3, 6 and 12 months were recorded using AOFAS forefoot, NPS and SF12 scores.

Results: 36 First metatarsal head resurfacing procedures were performed on 32 patients. Follow up ranges from 6 weeks to 18 months. Pre op scores averages were AOFAS 22.06 (8–52), SF12 35.55 (14–61.3) and NPS 8.03 (4–10). At 12 months, these average scores had improved significantly to AOFAS 82.57 (55–95) SF12 56.01 (27.5–63.4) and pain scores 0.69 (0–4). There was significant improvement of 60 points on the AOFAS forefoot score, 20 points on the SF12 scoring system, and significant decrease in pain scores of 7.34.

Discussion: Initial results of MTPJ resurfacing are encouraging. This technique provides an advantage over cheilectomy which is of limited use in late stage rigidus, and over resection arthroplasty which shortens the 1st MT and risks transfer metatarsalgia. In our practice metatarsal head resurfacing is providing a useful alternative to fusion in active patients who require movement of the MTPJ. Should patients not tolerate the procedure well, the added advantage is easy conversion to the gold standard of fusion. We continue to follow these patients and add further subjects to this study.