Modic Changes Increase the Cage Subsidence Rate in Spinal Interbody Fusion Surgery: A Systematic Review and Network Meta-Analysis

OBJECTIVE: To compare the effect of different Modic changes (MC) grades on the cage subsidence rate after spinal interbody fusion surgery.

METHODS: We comprehensively searched the PubMed, Embase, and Web of Science databases from inception to August 13, 2023, for relevant randomized controlled trials and prospective and retrospective cohort studies. Review Manager 5.3 and STATA13.0 were used to conduct this meta-analysis. The subsidence rate was assessed using relative risk and 95% confidence intervals.

RESULTS: Six studies with a total of 716 segments were allocated to four groups according to the type of MC. The subsidence rate in the non-Modic changes (NMC) was significantly lower than that in the MC. The subsidence rate in the NMC was significantly lower than that in the MC in the subgroup of cages with extra instrumentation. No significant difference was identified between the 2 groups in the oblique lumbar interbody fusion subgroup. The subsidence rate in the NMC was significantly lower than that in the MC in the transforaminal lumbar interbody fusion subgroup. The subsidence rate in the NMC was significantly lower than that in the MC1 and MC2. We found no significant difference between NMC and MC3, MC1 and MC2, MC1 and MC3, or MC2 and MC3.

CONCLUSIONS: MC may be associated with a higher cage subsidence rate. With the increase in MC grades, the incidence of subsidence decreased gradually, but it was always higher than that in the NMC. Oblique lumbar interbody fusion may be a better choice for the treatment of lumbar degenerative disease with MC.