Surgical Management of Monoarticular Rheumatoid Arthritis of the Fifth Metatarsophalangeal Joint.

Objective: To investigate the clinical and radiological outcomes in patients with monoarticular rheumatoid arthritis of the fifth metatarsophalangeal joint after Weil osteotomy.

Methods: From July 2011 to September 2015, 18 feet of 16 rheumatoid arthritis patients who underwent Weil osteotomy of the fifth metatarsal toe with a mean age at the time of surgery of 48.8 ± 7.4 years were reviewed retrospectively. The mean disease duration was 44.6 ± 6.8 months, and the follow-up period was 36 months. Clinical outcomes were evaluated according to the American Orthopaedic Foot and Ankle Society lesser metatarsophalangeal interphalangeal scale (AOFAS), 10-item SF-36 physical functioning and 2-item SF-36 bodily pain, Visual Analogue Scale (VAS), and satisfaction scores. In the radiologic evaluation, fifth metatarsophalangeal angle (MTP-5), lateral deviation angle (LDA), and longitudinal axes of the fifth metatarsal were measured on anterior-posterior (AP) weight-bearing radiographs preoperative and at the last follow-up.

Results: Clinical assessment showed that the total average of AOFAS was significantly increased from preoperative 53.6 ± 9.0 to 98.7 ± 2.0 points, and the VAS score was significantly decreased from preoperative 4.1 ± 1.5 to 1.1 ± 0.8 points at the last follow-up (P < 0.001). The total averages of SF-36 physical functioning and SF-36 bodily pain were significantly increased from preoperative 48.9 ± 9.0 to 99. ± 2.1 and from 61.4 ± 12.1 to 99.4 ± 2.4 points, respectively, at the last follow-up (P < 0.001). Subjectively, the excellent outcome of the surgery results were rated by 13 patients (81.3%) that underwent surgery and three patients (18.7%) were rated as good. Regarding radiographic parameters, the mean MTP-5 significantly decreased from 21.5° ± 1.2° preoperatively to 10.2° ± 1.2°, the mean LDA significantly decreased from 7.1° ± 1.2° preoperatively to -2.4° ± 1.0°, and the mean length of the fifth metatarsal was significantly shortened from 71.5 ± 1.4 preoperatively to 67.8 ± 1.5 mm at the final follow-up visit (P < 0.001). No malunion, nonunion, necrosis, pseudoarthrosis, or fracture of the fifth metatarsal was found. No exuberant bone growth, perforation of the screw, subluxation, or dislocation was observed. No indications of modification, revision or repeat surgery, or delayed wound healing were observed during follow-up period.

Conclusion: Surgical management of the monoarticular rheumatoid arthritis of the fifth metatarsophalangeal joint can achieve good clinical and radiological outcomes, with pain relief and dislocation reduction, as well as high satisfaction and improvement without recurrence or progression during the follow-up period.