MRI-based vertebral and endplate bone quality scores for assessing patient suitability in oblique lumbar interbody fusion with anterolateral screw fixation.

BACKGROUND: Oblique lumbar interbody fusion with anterolateral screw fixation (ASF) has been used to treat lumbar degenerative disease. Cage subsidence, a common OLIF complication, is significantly affected by low bone mineral density. Although MRI-based vertebral bone quality (VBQ) and endplate bone quality (EBQ) scores relate to bone density, their impact on OLIF with ASF remains unstudied. METHODS: This study reviewed data from patients who underwent OLIF combined with ASF from January 2021 to May 2023. We assessed cage subsidence (CS) by postoperative CT, while VBQ score and EBQ score were derived from MRI scans. Receiver operating characteristic (ROC) curve analysis was employed to assess the predictive accuracy of VBQ score and EBQ score. RESULTS: This study included a total of 219 patients, with 127 in the single-level group and 92 in the double-level group. The overall rate of CS in this study was 30.6%. For patients who experienced CS, the average VBQ score was 3.110 ± 0.639. Conversely, for patients without CS, the average VBQ score was lower at 2.635 ± 0.477 (P < 0.0001). In patients undergoing single-level OLIF-ASF, the VBQ scores were 3.499 ± 0.658 in patients with CS and 2.730 ± 0.496 in patients without CS (P < 0.0001). For double-level OLIF-ASF group, VBQ scores were 2.812 ± 0.438 in the CS subgroup and 2.461 ± 0.389 in the NCS subgroup (P = 0.0003). In the single-level group, we also assessed the EBQ score, which showed 2.750 ± 0.478 in the CS subgroup and 2.459 ± 0.492 in the NCS subgroup (P < 0.0001). The optimal cutoff value for the global VBQ score was determined to be 2.800. For the single-level group, the area under the curve (AUC) for VBQ score was 0.808, with an optimal cutoff value determined at 3.490 .In the double-level group, the AUC for VBQ score was 0.724, with the optimal cutoff value identified as 2.705. The AUC for EBQ score in the single-level group was 0.740, and the optimal cutoff value was determined to be 2.905 . CONCLUSIONS: The study found that for single-level cases, OLIF-ASF is advised only if VBQ is below 3.49 or EBQ is below 2.905. For double-level cases, OLIF-ASF is advised only if VBQ is below 2.705.