Comparison of Outcomes after Minimally Invasive Transverse Distal Metatarsal Osteotomy (MITO) and Proximal Phalangeal Osteotomy for Hallux Valgus With and Without Rheumatoid Arthritis: A Matched Cohort Study

Abstract

Background: There is an increasing role for joint-preserving surgery in hallux valgus (HV) management among patients with rheumatoid arthritis (RA). We compared radiologic and clinical outcomes after minimally invasive transverse distal metatarsal osteotomy (MITO) and a complete proximal phalangeal osteotomy for HV correction in patients with and without RA. Methods: This retrospective cohort study included 16 RA patients (21 feet) who underwent MITO between July 2018 and June 2023 with a minimum follow-up of 24 months. In total, 53 non-RA patients (63 feet) were matched by propensity score matching (1:3 ratio) after consideration of age, sex, body mass index, follow-up duration, preoperative hallux valgus angle (HVA), first-second intermetatarsal angle (1-2 IMA), and tibial sesamoid position (TSP). Radiologic evaluation included HVA, 1-2 IMA, and TSP measurements. Clinical outcomes were assessed using visual analog scale (VAS) pain scores, Foot and Ankle Outcome Scores, and Medical Outcomes Study Short Form Health Survey-36 physical component summary scores. Results: The matched cohorts consisted entirely of female patients, with a mean age of 63.7 years in the RA group and 63.3 years in the non-RA group. The mean follow-up duration was 38.1 months (range, 24-85 months). All radiologic parameters significantly improved at the last follow-up (all P < .001). Postoperative mean HVA, 1-2 IMA, and TSP were 4.9 degrees, 3.9 degrees, and 3, respectively, in the RA group and 7.0 degrees, 5.2 degrees, and 3, respectively, in the non-RA group; with the numbers available, no significant difference could be detected. Similarly, no significant difference could be detected in the final functional scores, and VAS met the predefined noninferiority margin. Likewise, no significant difference could be detected in total complications (P = 1.000) or reoperation rates (P = .184). Conclusion: MITO combined with a complete proximal phalangeal osteotomy yielded favorable radiographic improvements and noninferior pain relief in RA patients compared with non-RA patients. Our findings indicate that MITO with proximal phalangeal osteotomy may be a safe and effective minimally invasive joint-preserving surgical option for HV correction in RA patients without advanced first metatarsophalangeal joint destruction.