Indicators of sarcopenia and bone mineral density predict vertebral refracture after percutaneous kyphoplasty for osteoporotic vertebral compression fractures

This study aimed to explore the predictive value of sarcopenia-related indicators and bone quality indicators for vertebral refracture risk after percutaneous kyphoplasty (PKP) in patients with osteoporotic vertebral compression fractures (OVCF). This retrospective study enrolled OVCF patients receiving PKP from June 2018 to March 2024 with 2-year postoperative follow-up, and assigned to refracture and non-refracture groups. We collected baseline demographics, sarcopenia-related indicators and bone quality parameters. Intergroup comparisons, binary logistic regression and ROC curve analyses were performed via SPSS 19.0 to screen independent predictors and evaluate their predictive capacity for post-PKP vertebral refracture. A total of 134 OVCF patients undergoing PKP were enrolled in this study, including 26 patients with postoperative vertebral refracture and 108 without refracture. Baseline demographic, surgical, radiographic and laboratory characteristics were comparable between the two groups (all P > 0.05). The refracture group presented significantly reduced calf circumference, lower bone mineral density (BMD), weaker grip strength, decreased CT HU values and lower psoas muscle atrophy index (all P < 0.05), while no significant difference in psoas muscle index was found ( P > 0.05). Binary logistic regression analysis demonstrated that grip strength, BMD, CT HU value, and psoas muscle atrophy index were independent protective factors for post-PKP vertebral refracture. Grip strength was positively correlated with BMD ( R = 0.66, R²=0.429, B = 0.162, P < 0.001) and CT HU value ( R = 0.486, R²=0.219, B = 4.936, P < 0.001). The psoas muscle atrophy index showed a strong positive correlation with BMD ( R = 0.94, R²=0.880, B = 6.653, P < 0.001) and a moderate positive correlation with CT HU value ( R = 0.540, R²=0.292, B = 163.759, P < 0.001). ROC curve analysis revealed that BMD (AUC = 0.782) and psoas muscle atrophy index (AUC = 0.785) achieved moderate-to-good predictive efficacy for refracture risk, whereas CT HU value (AUC = 0.661) and grip strength (AUC = 0.625) exhibited relatively lower discriminatory performance. BMD, CT HU value, grip strength and psoas muscle atrophy index were correlated with post-PKP vertebral refracture risk in this single-center cohort of OVCF patients. Only BMD and the psoas muscle atrophy index exhibited moderate-to-good discriminative ability, though the optimal cutoff thresholds identified in this study lack external multicenter validation. This study confirms significant correlations between bone quality and sarcopenia-related indicators in OVCF patients.