Photo Credit: Benito Vega
The following is a summary of “MRI-based vertebral bone quality score is a predictor of pedicle screw loosening following instrumented posterior lumbar fusion,” published in the January 2025 issue of Rheumatology by Hu et al.
Researchers conducted a retrospective study to evaluate the MRI-based vertebral bone quality (VBQ) score as a predictor of pedicle screw loosening after instrumented transforaminal lumbar interbody fusion (TLIF).
They analyzed data from patients undergoing 1 or 2-level TLIF between February 2014 and March 2015. Screw loosening was diagnosed when the radiolucent zone exceeded 1 mm on radiographs. VBQ scores were calculated using T1-weighted MRI sagittal images, dividing the median signal intensity of L1-L4 by cerebrospinal fluid intensity at L3. Univariate and multivariate logistic regression analyses assessed predictors, and ROC curve analysis evaluated VBQ score performance.
The results showed that 75 of 211 patients (35.55%) had pedicle screw loosening at 24 months. Higher VBQ scores (OR: 27.887 ± 0.514, 95% CI: 10.189–76.326), male sex (OR: 0.323 ± 0.483, 95% CI: 0.126–0.833), and longer fusion length (OR: 2.578 ± 0.545, 95% CI: 1.166–5.701) were significant factors. The VBQ score predicted screw loosening with 78.9% accuracy.
Investigators found that a higher VBQ score independently predicted pedicle screw loosening after instrumented TLIF and concluded it was a reliable tool for preoperative bone quality assessment.