Clinical Value of Paraspinal Muscle Quality Changes in Risk Assessment of Osteoporotic Vertebral Compression Fracture.
BACKGROUND Osteoporotic vertebral compression fractures (OVCFs) are often underestimated by conventional tools. Paraspinal muscle quality changes, especially reduced cross-sectional area (CSA) and increased fatty infiltration (FI), may provide additional clinical value for OVCF risk. MATERIALS AND METHODS We retrospectively enrolled 258 osteoporosis patients aged ≥50 years. After propensity score matching, 129 patients with vertebral fractures and 129 without fractures were included. Demographics, BMD T-scores, and FRAX scores were collected. Paraspinal muscle CSA and FI at the L3 level were quantified on axial T2WI using ImageJ. Group comparisons and multivariable logistic regression were performed, and diagnostic performance was evaluated using ROC analysis. RESULTS Compared with the non-fracture group, fracture patients had significantly lower weight, BMI, and CSA but higher FRAX scores and FI. FI remained elevated in the fracture group across all BMI subgroups (P<0.05), whereas CSA reduction was significant only in the normal-weight subgroup (P=0.001). FI was an independent risk factor for OVCF (OR=1.091, 95% CI: 1.041-1.144; P<0.001). FI showed higher discrimination (AUC=0.702) than BMD T-score (AUC=0.517) and FRAX (AUC=0.592). The combined model achieved the best performance (AUC=0.776; sensitivity 54.4%, specificity 89.7%; all P<0.05). DISCUSSION Paraspinal FI, a marker of muscle quality deterioration, provides complementary risk information beyond BMD and FRAX and may help identify high-risk individuals who are underestimated by traditional assessments. CONCLUSION Paraspinal muscle FI is an independent risk factor for OVCF and improves prediction when added to traditional tools.