A propensity score-matched comparison between single-stage and multistage anterior/posterior lumbar fusion surgery: a Michigan Spine Surgery Improvement Collaborative study

OBJECTIVE Patients undergoing anterior/posterior lumbar fusion surgery can undergo either a single-stage or multistage operation, depending on surgeon preference. The goal of this study was to assess different patient outcomes between single-stage and multistage lumbar fusion procedures in a multicenter setting. METHODS The Michigan Spine Surgery Improvement Collaborative database was queried for anterior/posterior lumbar fusion surgeries between July 2018 and January 2022. Patients who underwent either single-stage or multistage procedures were included. For multistage procedures, the first surgery included both anterior lumbar interbody fusions and lateral lumbar interbody fusions. Primary outcomes included postoperative complications and improvement in patient- reported outcomes: Patient-Reported Outcomes Measurement Information System Physical Function, EQ-5D, and satisfaction. The two cohorts were propensity score matched, while Poisson generalized estimating equation models were used for multivariate analyses. RESULTS After one-to-one propensity score matching, 355 patients were identified in the single-stage and multistage cohorts. Single-stage procedures were associated with a lower risk of complications (p = 0.024), fewer emergency department visits (p = 0.029), and higher patient satisfaction after 1 year (p = 0.026) and 2 years (p = 0.007), compared with multistage procedures. After adjusting for baseline patient and operative characteristics, patients undergoing multistage procedures had a higher risk of complications (relative risk [RR] 1.17, 95% CI 1.02-1.34; p = 0.026), were less likely to be satisfied after 1 year (RR 0.83, 95% CI 0.74-0.93; p < 0.001), and were less likely to experience improvement in back pain after 90 days (RR 0.86, 95% CI 0.75-0.99; p = 0.039) and 2 years (RR 0.76, 95% CI 0.60-0.96; p = 0.023). CONCLUSIONS The authors observed that patients who undergo lumbar fusion surgery using a multistage approach have higher postoperative complication rates and are less likely to report satisfaction compared with a matched, single- stage procedure cohort.