Study Design: Retrospective cohort study. Objectives: To compare 90-day complication rates and clinical outcomes in patients undergoing minimally invasive lumbar fusion with and without inflammatory arthritis. Summary of Background Data: Patients with inflammatory arthritis are at special risk of developing spinal pathology. There is a paucity of literature investigating outcomes following minimally invasive lumbar fusion in patients with inflammatory arthritis. Methods: Patients who had undergone minimally invasive fusion between 2017 and 2023 for the treatment of degenerative pathology of the lumbar spine with a minimum of 6 months follow-up were included and separated into inflammatory arthritis (IA) or noninflammatory arthritis (non-IA) cohorts. Patient demographics, perioperative variables, 90-day complications, patient-reported outcome measures, and rates of MCID achievement were compared between the IA cohort and the unmatched and 3:1 case-control matched non-IA cohort at early (<6 mo) and late (≥6 mo) follow-up. Results: Six hundred sixty-nine patients were included (IA cohort, n=23; non-IA cohort, n=646). Patient demographics and perioperative characteristics did not differ significantly between the two cohorts except for IA patients reporting a higher age-adjusted Charlson comorbidity index ( P =0.004). There were no significant differences in 90-day complications, reoperations, or readmissions. The IA cohort demonstrated significant improvements in most PROMs at the early and late postoperative time points. PROM scores, magnitudes of improvement in PROMs, MCID achievement rates, and time to achieve MCID for most PROMs were not significantly different between the 2 cohorts. After 3:1 case-control matching, there were no significant differences in complications, reoperations or admissions. In addition, there were no significant differences between the two cohorts in most PROM scores or rates of MCID achievement. Magnitudes of improvement and time to achieve MCID were comparable between the two cohorts for all PROMs. Conclusion: Patients with inflammatory arthritis undergoing minimally invasive lumbar fusion have similar clinical outcomes as compared with controls. Level of Evidence: Level III.
Kwas et al. (Wed,) studied this question.