Experience of High Tibial Osteotomy for Patients with Rheumatoid Arthritis Treated with Recent Medication: A Case Series

<b>Background</b>: High tibial osteotomy (HTO) was generally not indicated in patients with rheumatoid arthritis (RA) because synovial inflammation may exacerbate joint damage postoperatively. Recently, joint destruction in RA has dramatically changed with the introduction of methotrexate (MTX) and biological disease-modifying antirheumatic drugs (bDMARDs). This study aimed to investigate the clinical outcomes of HTO for patients with RA treated with recent medication. <b>Methods</b>: In this study, patients with RA who underwent HTO between 2016 and 2020 were retrospectively reviewed. Patients whose follow-up period was <2 years and those whose onset of RA occurred after HTO were excluded. Clinical outcomes were investigated using the Japanese orthopedic Association (JOA) and visual analog scale (VAS) scores. <b>Results</b>: Seven patients (two males and five females, mean age 72.0 ± 6.2 years, mean body mass index 24.0 ± 2.9 kg/m²) were included in this study. The mean follow-up period was 62.1 ± 21.4 months. Open-wedge and hybrid closed-wedge HTO were performed in two and five cases, respectively. MTX was used for all cases. The bDMARDs were used in six cases (golimumab and tocilizumab in four and two cases, respectively). JOA scores significantly improved from 63.6 ± 10.7 preoperatively to 90.7 ± 5.3 postoperatively (<i>p</i> = 0.0167 Wilcoxon rank test). VAS scores significantly decreased from 48.6 ± 12.2 preoperatively to 11.4 ± 6.9 postoperatively (<i>p</i> = 0.017 Wilcoxon rank test). None of the patients underwent total knee arthroplasty. <b>Conclusions</b>: This study showed seven RA patients who underwent HTO treated with recent medication. The prognosis of RA, including joint destruction, has dramatically improved with induction of MTX and bDMARDs. HTO may be one of effective joint preservation surgeries even for patients with RA. To achieve the favorable outcomes, surgeons should pay attention to timing and indication of surgery.