Differences in the outcomes of anterior versus posterior interbody fusion surgery of the lumbar spine: A propensity score-controlled cohort analysis of 10,941 patients

Abstract

Few studies have measured outcome differences between the various available spinal fusion techniques. We compare long-term outcomes of anterior versus posterior lumbar interbody fusion. Using the MarketScan database (Truven Health Analytics, Ann Arbor, MI, USA) we selected patients ⩾18years old who underwent lumbar fusion surgery from 2000–2009 using either approach. Exclusion criteria included circumferential fusion, and having less than 1year of preoperative or less than 2years of postoperative follow-up. Using an inverse probability-weighted propensity-score model we compared reoperation and 90day complication rates, and postoperative health resource utilization of both approaches. A total of 10,941 patients were identified. Of these, 7460 (68.2%) and 3481 (31.8%) underwent posterior and anterior interbody fusion, respectively. Anterior fusion patients had a higher 2year reoperation rate (odds ratio 1.43, 95% confidence interval [CI]: 1.21–1.70, p<0.0001), although differences became non-significant at maximum follow-up (p=0.0877). The 90day complication rate was 15.7%, with anterior fusion patients being more likely to experience complications (relative risk 1.24, 95%CI: 1.13–1.36, p<0.0001). Anterior fusion patients also had greater levels of postoperative health utilization, surpassing posterior fusion patients by an average of $US7450 in total charges (95% CI: $4670–$10,220, p<0.0001). As currently practiced in the USA, anterior lumbar surgical approaches may be associated with higher postoperative morbidity and reoperation rates than posterior fusion approaches.