Outcomes of Degenerative and Isthmic Spondylolisthesis After Lumbar Fusion Surgery: A Systematic Review and Meta-analysis

Introduction: Lumbar spondylolisthesis can lead to significant disability by causing back and lower extremity pain. Degenerative (DS) and isthmic (IS) are the two most common types of spondylolistheses. DS is the result of arthritic changes and degenerative disc disease whereas IS occurs secondary to a pars interarticularis defect. The objective of the present study was to compare surgical outcomes after DS and IS.

Methods: A systematic literature review and meta-analysis was performed according to the PRISMA guidelines.

Results: A total of 20 studies comprising 3,136 patients were included (DS-1,944; IS-1,192). The majority of patients had a Grade 1 or 2 spondylolisthesis at L4/L5 or L5/S1 and a weighted mean age of 57.9 years old. Mean follow-up duration was 36.3months. No differences were identified in terms of estimated blood loss (EBL) (MD: 5.79, 95%CI: -42.88, 54.46; I2=81.7%), length of stay (LOS) (MD: -0.24, 95%CI: -1.38, 0.90; I2=87.7%), duration of operation (MD: -2.73, 95%CI: -20.61, 15.16; I2=84.7%), reduction of Visual analog scale (VAS) for back pain before and after surgery (MD: -0.01, 95%CI: -0.68, 0.65; I2=87.5%), reduction in Oswestry Disability Index (ODI) before and after surgery (MD: 1.37, 95%CI: -2.39, 5.12; I2=75.5%), return to operating room (OR) for any reason (OR:1.01, 95%CI: 0.48, 2.15; I2=0%), successful fusion at last follow-up (OR:0.68, 95%CI: 0.26, 1.77; I2=60.5%), adjacent segment disease (ASD) during follow-up (IS: 8.2%, DS: 14.5%; OR:0.45, 95%CI: 0.18, 1.13; I2=0%).

Conclusion : No statistically significant differences were found in terms of EBL, LOS, operative duration, reduction in VAS score, reduction in ODI, return to OR, and bony fusion post-operatively. The development of ASD during follow-up was 8.2% and 14.5% for the IS and DS groups respectively; even though the differences did not reach the level of statistical significance, it is possible that the analysis was underpowered to detect this difference.