Low Bone Mineral Density Promotes Cement Leakage in Vertebra with Compression Fracture After Percutaneous Vertebroplasty

Objective: To explore influence of different bone mineral density (BMD) on cement leakage and biomechanics after vertebroplasty for treatment of osteoporotic vertebral compression fractures, thus to offer individualized treatment modality and reduce occurrence of cement leakage. Methods: BMD of 45 vertebral bodies from nine embalmed cadavers was measured using Dual Emission X-ray Absorptiometry (DEXA). Vertebral bodies were divided into 3 groups: high BMD group, middle BMD group and low BMD group (n = 15). Compression vertebral fracture model was established and followed by unilateral vertebroplasty. The biomechanical testing was carried out before fracture and after cement injection. The cement leakage rate and cement distribution were assessed by postoperative CT scan. Results: After vertebroplasty, decreased stiffness appeared in 14 (70%), 11 (55%) or 4 (20%) vertebras of high, middle or low BMD groups, percentage changes among the three groups were statistically significant, trend test also showed increased vertebral stiffness with decrease of BMD; cement leakage appeared in 12 (60%), 10 (50%) or 6 (30%) vertebras of high, middle or low BMD groups, trend test showed that the vertebras without cement leakage increased with decrease of BMD. The vertebral load could be increased after vertebroplasty regardless of the vertebral BMD level. The vertebral load increased after vertebroplasty versus that before vertebroplasty in all the three groups (P < 0.001), while the amplitude of the increase showed no significant difference. The stiffness values post-vertebroplasty showed statistically significant differences among the high BMD, the middle BMD and the low BMD groups (P < 0.01). The mean stiffness changes after vertebroplasty in the high BMD group showed a decreased trend, and an increased trend in the low BMD group. Conclusion: After vertebroplasty, the vertebral load and stiffness were related with BMD, and the cement leakage rate also showed the association trend.