Methods: This single-center study included 130 patients with osteoporotic vertebral fractures who underwent BKP and preoperative computed tomography and magnetic resonance imaging. After propensity score matching for age; sex; body mass index; fracture level; use of steroids, teriparatide, or osteoporosis medication; and previous AVF, patients were classified into the AVF (−) and AVF (+) groups, each of which included 34 patients. Bone strength was assessed using the L1 HU, L1–4 HU (mean HU of L1–L4), L1 VBQ, and L1–4 VBQ. Group differences were analyzed, and the predictive accuracy for AVF was evaluated using area under the receiver operating characteristic curve (AUC). Results: L1 HU was significantly lower in the AVF (+) group than in the AVF (−) group (92.1±29.4 vs. 71.6±21.4, p =0.013). No significant differences between the groups were observed for L1–4 HU, L1 VBQ, and L1–4 VBQ. L1 HU had the highest AUC (0.657), compared with those for L1–4 HU (0.625), L1 VBQ (0.524), and L1–4 VBQ (0.523). The predictive accuracy of L1 was superior to that of L1–4 for both HU and VBQ scores. Conclusions HU was superior to VBQ in predicting AVF risk after BKP, with L1 HU being the most effective indicator of bone strength and AVF risk.