硫酸钙骨水泥增强椎弓根螺钉置入骨质疏松椎体的瞬时稳定性

背景：由于内固定在骨质疏松骨上锚着力较差影响了其稳定性，因此需要新的固定方法，使用骨水泥或骨替代物增强内固定技术可以较好地解决这个问题。 目的：评价硫酸钙骨水泥增强的椎弓根螺钉置入骨质疏松椎体后的瞬时稳定性。 方法：选取新鲜小牛脊柱椎体，测量骨密度后，随机分为4组：①正常椎体椎弓根螺钉内固定组。②正常椎体椎弓根螺钉+硫酸钙骨水泥增强内固定组。③骨质疏松椎体椎弓根螺钉内固定组。④骨质疏松椎体椎弓根螺钉+硫酸钙骨水泥增强内固定组。将相同规格的椎弓根螺钉拧入测试椎体的椎弓根，测试其即刻最大轴向拔出力和最大破坏功耗，以评价硫酸钙骨水泥增强椎弓根螺钉的瞬时稳定性。 结果与结论：骨质疏松椎体较正常椎体的螺钉最大拔出力、最大破坏功耗明显减少(P < 0.05)，而二者分别以骨水泥增强后的螺钉最大拔出力、最大破坏功耗明显增加(P < 0.05)；正常组和骨质疏松组以骨水泥增强后螺钉的最大拔出力、最大破坏功耗相当。提示硫酸钙骨水泥增强后可以增加内固定螺钉的瞬时稳定性，硫酸钙骨水泥可以应用于骨质疏松患者骨折内固定的增强，具有较好的临床应用前景。中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程全文链接：

Calcium sulfate cement augments transient stability of pedicle screw in osteoporotic vertebral body

BACKGROUND:Poor implant anchorage in osteoporotic bone impacts its stability and requires the new solutions for the treatment. The augmentation technique with bone cements or bone substitutes is one strategy for the solutions. OBJECTIVE:To evaluate the transient stability of pedicle screw augmented using calcium sulfate cement in osteoporotic vertebral body. METHODS:Fresh calf lumbar vertebrae were selected to measure bone density, and then classified into four groups: the group by pedicle screw in normal vertebral body; the group by pedicle screw augmented using calcium sulfate cement in normal vertebral body; the group by pedicle screw in osteoporotic vertebral body; the group by pedicle screw augmented using calcium sulfate cement in osteoporotic vertebral body. Pedicle screw of equal specification was twisted into the tested pedicle of vertebral arch. The maximum axial screw pull-out strength and the maximum energy required to failure were recorded so as to assess the transient stability of pedicle screw augmented using calcium sulfate cement.   RESULTS AND CONCLUSION:The maximum screw pull-out strength and the maximum energy required to failure were significantly less in osteoporotic vertebral body compared with normal vertebral body (P < 0.05). The maximum screw pull-out strength and the maximum energy required to failure after augmentation using calcium sulfate cement were significantly increased (P < 0.05). The maximum screw pull-out strength and the maximum energy required to failure after augmentation using calcium sulfate cement were identical between normal group and osteoporosis group. These results suggested that calcium sulfate cement could effectively increase the transient stability of pedicle screw. Calcium sulfate cement is effective in augmenting fixation in osteoporotic bone, and has potential in clinical application.