Adjacent segment disease after lumbar interbody versus posterolateral fusion: A systematic review and meta-analysis of proportions

Introduction: Transforaminal lumbar interbody fusion (TLIF) and posterolateral fusion (PLF) are common posterior fusion surgical techniques for treating single-level lumbar degenerative disease. Despite being in practice for nearly 30 years, there is no consensus on their technical superiority. Our research aimed to compare adjacent segment disease (ASD) in both techniques.

Methods: A systematic review of PubMed, EMBASE and Scopus databases was performed to identify studies describing TLIF and PLF outomes in the treatment of single level lumbar degenerative disease. The search terms used were: Posterolateral fusion, single level degenerative disease, MIS interbody fusion, minimally invasive surgery interbody fusion, clinical outcome, radiological outcome. The authors excluded case reports, cadaveric and animal studies, literature reviews and pediatric populations; studies with interbody fusions than TLIF and studies with different pathologies. Data was extracted by hand and analyzed in R version 4.3.1.

Results: The meta-analysis followed PRISMA guidelines. Pooled analysis for blood loss was 416.12 ± 173.07, 270.15 ±170.32 and 187.44 ± 73.76 mL for PLF, oTLIF and MI-TLIF respectively with both interbody fusions being significant compared to PLF (p < 0.01 for both). Analysis for length of stay was 4.6 ± 3.72, 4.43 ± 2.08 and 3.66 ± 4.1 days for PLF, oTLIF and MI-TLIF respectively with MI-TLIF being significant compared to PLF (p < 0.05). There was no difference in mean operative times of 169.12 ± 138.84, 150.16 ± 21.54 and 157.27 ± 50.11 minutes for PLF, oTLIF and MI- TLIF. When assessing ASD, random effects models were 0.05 (0.02-0.09) and 0.10 (0.02-0.24) with and without interbody fusion respectively with no significant difference (p=0.29).

Conclusion : There is no difference in adjacent segment disease (ASD) rates between one-level interbody or posterolateral fusion in the lumbar spine. There is less blood loss and decreased length of stay in interbody fusion. This is likely due to implementation of less invasive techniques with interbody fusions.