Lumbar Spine Endplate Sclerosis is a Protective Factor for Cage Subsidence in Minimally Invasive Transforaminal Lumbar Interbody Fusion

Study design Retrospective single-center cohort study. Objective To investigate the predictive value of preoperative endplate Hounsfield unit (HU) measurements for cage subsidence (CS) following minimally invasive transforaminal lumbar interbody fusion (MI-TLIF), and to propose threshold values for risk stratification. Methods A total of 169 patients undergoing one- and two-level MI-TLIF with preoperative lumbar CT imaging were included. Endplate HU values were quantified within a 5-mm region of interest at the cage–endplate interface. Mild and severe CS was defined as 2-4 mm and ≥4 mm migration of the interbody cage into the adjacent vertebral endplate. Logistic regression analyses were employed to identify risk factors for CS. Results CS occurred in 39 of 464 endplates. Significantly lower L1 vertebral HU, reduced endplate HU at the surgical site, and obesity (BMI >25 kg/m 2 ) were observed in the CS group. In multivariate analysis, obesity and endplate HU were independent predictor of CS (OR = 2.508; 95% CI, 1.135-5.546; OR = 0.989; 95% CI, 0.983-0.995). Among patients with L1 HU 25 kg/m 2 ) and endplate HU was 0.727 (95% CI 0.655-0.800). Conclusions Surgical site endplate sclerosis at the surgical site may be a protective factor against CS following MI-TLIF. Preoperative endplate HU assessment may assist in identifying patients at risk of CS following MI-TLIF.