Outcomes Comparison Between Oblique Lumbar Interbody Fusion and Minimally Invasive Transforaminal Lumbar Interbody Fusion in Low-Grade Spondylolisthesis: A Randomized Clinical Trial.

BackgroundMinimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and oblique lumbar interbody fusion (OLIF) are widely used for treating spondylolisthesis patients, but there is no randomized controlled trial study that directly compared OLIF and MIS-TLIF.MethodsSixty patients who underwent single-level surgery at L4 to L5 were randomly allocated to the MIS-TLIF or OLIF group. Primary clinical outcomes were visual analog scale (VAS) of back and leg pain, Oswestry Disability Index (ODI) scores, and EQ-5D-5L. Secondary outcomes were radiological outcomes including disc height (DH), foraminal height (FH), foraminal area (FA), cross-sectional area of spinal canal, spinal canal diameter, and fusion rates.ResultsBoth groups showed significant improvements in clinical outcomes from baseline to each subsequent postoperative period. Predicted mean change (95% CI) in VAS back, VAS leg, ODI scores, and EQ-5D-5L were -3.9 (-4.6 to -3.1), -5.6 (-6.2 to -5.1), -15.7 (-19.0 to -12.5), and 25.4 (21.3-29.6), respectively. Clinical differences in both groups over total follow-up were not statistically significant: VAS back -0.38 (-0.87 to 0.11); P = 0.18, VAS leg: -0.40 (-0.81 to 0.02); P = 0.08, ODI: 0.4 (-1.9 to 2.8); P = 0.7 and EQ-5D-5L: 0.1 (-1.9 to 2.2); P = 0.9. Radiological parameters significantly improved from baseline to early postoperation in both groups. Changes in DH, FH, and FA were lower in MIS-TLIF compared with OLIF. The cross-sectional area of spinal canal change was higher in MIS-TLIF compared with OLIF. Spinal canal diameter change was not different between groups. Fusion rates were similar in both groups.ConclusionsPatient-reported outcomes were significantly improved in both MIS-TLIF and OLIF groups without significant differences between both procedures. OLIF demonstrated advantages in restoration of DH, FH, FA, and lower intraoperative blood loss compared with MIS-TLIF.Clinical relevanceBoth MIS-TLIF and OLIF offer comparable clinical benefits for patients with single-level degenerative spondylolisthesis. However, OLIF may be preferred in cases where greater restoration of disc and foraminal dimensions and reduced intraoperative blood loss are desired.Level of evidence: 1