In Single-level, Open, Posterior Lumbar Fusion, Does Transforaminal Lumbar Interbody Fusion or Posterolateral Fusion Lead to Better Outcomes?

Introduction: Two common approaches for one-level, posterior lumbar fusions include transforaminal lumbar interbody fusion (TLIF) and posterolateral fusion (PLF) alone without an interbody. Despite prior research, whether to offer a TLIF or a PLF alone in certain cases of degenerative lumbar pathology remains an active area of study. In patients undergoing open, one-level, posterior lumbar fusion, we sought to compare TLIF versus PLF alone in: 1) discharge disposition, 2) return to work (RTW), and 3) patient-reported outcomes (PROs).

Methods: A single-center, retrospective cohort study was undertaken between 10/2010-05/2021, all with 1-year follow-up, and excluding patients with isthmic spondylolisthesis. Minimum clinically important difference (MCID) for each PRO was used, which included Numeric Rating Scale (NRS) and Oswestry Disability Index (ODI). Logistic/linear regression controlled for age, BMI, disc height, flexion-extension movement, amount of movement on flexion-extension, and spondylolisthesis grade.

Results: Of 850 patients undergoing open, one-level, posterior lumbar fusion, 591(69.5%) underwent a TLIF and 259(30.5%) underwent a PLF alone. Patients undergoing TLIF were younger (59.0±11.3 vs. 63.3±12.6,p < 0.001), had higher BMI (31.3±6.6 vs. 30.2±12.6,p=0.019), and more private insurance (50.3% vs. 39.0%, p< 0.001). Regarding discharge disposition, no significance was found in multivariate regression (OR=2.07, 95%CI=0.39-10.82, p=0.385) and similar RTW was seen (80.8% vs. 80.4%, p=0.645), (OR=1.15, 95%CI=0.19-6.81,p=0.873). Regarding PROs, patients undergoing a TLIF had higher preoperative (6.7±2.3 vs.6.4±2.5, p=0.046) and 3-month NRS-back pain (3.4±2.6 vs. 2.9±2.5,p=0.036); with similar 12-month NRS-back pain. Regarding NRS-leg pain, no differences were observed preoperatively (p=0.532) and at 3-months (p=0.808). No other significant differences in ODI.

Conclusion : TLIF patients had slightly higher NRS-back pain at baseline and 3-months, but similar NRS-leg pain, despite the added risk of placing an interbody. No differences were seen in discharge disposition, RTW, and 12-month pain scores and ODI.