Modified Scarf Osteotomy with Medial Capsule Interposition for Hallux Valgus in Rheumatoid Arthritis: A Study of Cases Including Severe First Metatarsophalangeal Joint Destruction.

BACKGROUND: Arthrodesis of the first metatarsophalangeal (MTP) joint has been recommended for severe hallux valgus deformity in patients with rheumatoid arthritis (RA). However, with the progress of medical treatment of RA, joint preservation surgery has recently been performed. The aim of this study was to investigate the clinical and radiographic outcomes of modified Scarf osteotomy with medial capsule interposition for RA cases including severe destruction of the first MTP joint and to evaluate risk factors for recurrence.

METHODS: A retrospective observational study of 76 cases (60 patients) followed for a mean of 35.3 months (range, 24 to 56 months) after a modified Scarf osteotomy was performed. Scores on the Japanese Society for Surgery of the Foot (JSSF) RA foot and ankle scale, the JSSF hallux scale, and a self-administered foot evaluation questionnaire (SAFE-Q) were determined along with preoperative and postoperative radiographic parameters.

RESULTS: There was a significant improvement, from preoperatively to final follow-up, in the mean JSSF RA foot and ankle score (from 52.2 to 76.9 points) and the mean JSSF hallux score (from 38.2 to 74.5 points). There was a recurrence (hallux valgus angle [HVA] of >20°) in 12 feet (16%). The preoperative DAS28-CRP score (disease activity score [based on 28 joints in the body]-C-reactive protein score) and intermetatarsal angles between the first and second metatarsals (M1M2A) and between the first and fifth metatarsals (M1M5A) were significantly greater in the recurrence group, as were the HVA, M1M2A, M1M5A, and Hardy grade at 3 months after surgery. There was a significant negative correlation between the preoperative DAS28-CRP score and the JSSF RA foot and ankle score at final follow-up (β = -0.39, p = 0.02) and a significant positive correlation between the preoperative DAS28-CRP score and the HVA at final follow-up (β = 0.44, p = 0.001).

CONCLUSIONS: The modified Scarf osteotomy with medial capsule interposition for hallux valgus deformity improved clinical and radiographic outcomes in RA cases with severe destruction of the first MTP joint. Increased preoperative M1M2A and M1M5A; incomplete reduction of the sesamoid bone; and the HVA, M1M2A, and M1M5A at 3 months after surgery should be evaluated as they are associated with recurrence of the deformity. The preoperative DAS28-CRP score was associated with the clinical and radiographic outcomes after surgery.

LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.