MRI-based endplate bone quality predicts bony fusion and cage subsidence after PLIF in patients with Modic changes
Xiaoxia Qiao1, Zhao Guo1, Tong Li1
1Affiliated Hospital of Hebei University, Baoding, China.
Background:
Modic changes (MCs) are classified into non- sclerotic and sclerotic types based on endplate morphology. Our previous work showed that non- sclerotic MCs increase cage subsidence risk after posterior lumbar interbody fusion (PLIF), while sclerotic MCs reduce bony fusion rates. Endplate bone quality (EBQ), an magnetic resonance imaging (MRI)- derived surrogate for regional bone density, may predict these distinct complications. This study evaluated EBQ's predictive value for cage subsidence in the non- sclerotic group and for bony fusion failure in the sclerotic group.
Methods:
We retrospectively reviewed 189 patients (mean age 52.6 years, 62.5% female) who underwent single- segment PLIF for degenerative lumbar disease with MCs. Patients were divided into non- sclerotic (n=108) and sclerotic (n=81) groups based on preoperative computed tomography (CT) and MRI. EBQ was calculated as the average signal intensity of the subchondral bone 3 mm above and below the surgical level divided by the cerebrospinal fluid signal at L3. Cage subsidence and bony fusion were assessed on CT at minimum 1- year follow- up. Binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed.
Results:
In the non- sclerotic group, higher EBQ independently predicted cage subsidence (OR = 1.539, 95% CI: 1.034- 2.291, P<0.05), with an AUC of 0.809 (95% CI: 0.684- 0.934). The optimal cutoff was 3.015, yielding 90.0% sensitivity and 67.3% specificity. In the sclerotic group, lower EBQ independently predicted non- fusion (OR = 1.404, 95% CI: 1.007- 1.956, P<0.05), with an AUC of 0.784 (95% CI: 0.675- 0.892) and optimal cutoff of 1.745 (72.6% sensitivity, 78.9% specificity).
Conclusion:
EBQ serves as a dual predictive biomarker: high EBQ identifies non- sclerotic patients at risk for cage subsidence, while low EBQ identifies sclerotic patients at risk for fusion failure. Preoperative EBQ assessment can guide personalized surgical strategies to reduce complications and improve outcomes.