Is rheumatoid arthritis associated with worse outcomes following adult spinal deformity surgery?

Rheumatoid arthritis (RA) is a chronic inflammatory disease, frequently involving the spine;however, its impact on adult spinal deformity (ASD) surgery outcomes remains inconclusive. In patients undergoing ASD surgery, we sought to evaluate: 1) impact of RA on mechanical complications and patient-reported outcome measures (PROMs) and 2) effect of steroid-use and disease modifying antirheumatic drugs DMARDs on postoperative outcomes.

A retrospective cohort study was performed for patients with RA undergoing ASD surgery from 2009 to 2021. Inclusion criteria were: ≥ 5-level fusion, and 2-year follow-up. The primary outcomes of interest were reoperation, mechanical complications and PROMs. Bivariate and multivariable analyses were performed.

Among 238 patients undergoing ASD surgery, 34 (14.3 %) had RA, for a mean of 9.6 ± 4.4 years. Ten patients (29.4 %) were on steroids, and 14 (41.2 %) were on DMARDs preoperatively. Patients with RA had more proximal junctional kyphosis/ failure (PJK/F) (76.5 % vs. 42.6 %,p = 0.002), pseudarthrosis (44.1 % vs. 25.0 %,p = 0.021), and need for reoperation (58.8 % vs. 33.8 %, p = 0.005) compared to patients without RA, with no difference in other complications. On multivariable regression, RA was an independent predictor of PJK/F (OR=2.76, 95 %CI=1.03-7.39,p = 0.043) and reoperation (OR=2.51, 95 %CI=1.00-6.25,p = 0.048). Patients receiving DMARDs had a lower reoperation rate (28.6 % vs. 80.0 %,p = 0.003), with no significant difference in 2-year PROMs between the cohorts. Years of RA diagnosis or being on steroids had no association with outcomes.

RA significantly increased the risk of mechanical complications and reoperation following ASD surgery. However, the use of DMARDs reduced the likelihood of reoperation, emphasizing the importance of prioritizing medical management of RA patients prior to surgery.