Rotter Robert, Pflugmacher Robert, Kandziora Frank, Ewert Andreas, Duda Georg, Mittlmeier Thomas
Department of Trauma & Reconstructive Surgery, University of Rostock, Rostock, Germany.
Spine (Phila Pa 1976). 2007 Jun 1;32(13):1400-5. doi: 10.1097/BRS.0b013e318060a622.
Biomechanical study of human osteoporotic lumbar vertebrae following prophylactic kyphoplasty.
To evaluate the potential benefits of different resorbable candidate materials for use in prophylactic kyphoplasty compared with the behavior of polymethylmethacrylate cement.
Kyphoplasty using PMMA bone cement for the stabilization of fractured osteoporotic vertebrae has been established as a useful clinical tool. In several studies, consecutive compression fractures have been reported in vertebrae caudal or cranial to those augmented with bone cement. Consequently, some physicians have begun to treat adjacent vertebrae by means of prophylactic augmentation.
Biomechanical in vitro testing was performed on 40 human osteoporotic nonfractured lumbar vertebrae. Three types of bone cement (PMMA, 2 different calcium phosphate cements) and one silicon derivative were assessed during compressive and cyclic sinusoidal testing. Each candidate material was applied bipedicularly under fluoroscopic control.
Differing processing qualities of the materials led to substantial differences during cement injection, in particular in the amount of cement filling of the vertebrae. However, in comparison to native vertebrae, augmented specimens showed significantly higher compressive failure. No significant differences between vertebral bodies treated with PMMA and those treated with either type of calcium phosphate cement were documented. The biomechanical properties of the vertebrae could not be significantly improved by the silicon derivative.
This study demonstrated that calcium phosphate cements displayed identical behavior to PMMA cement with respect to in vitro mechanical qualities. Consequently, from a mechanical viewpoint, calcium phosphate cements may be used in addition to PMMA cement for kyphoplasty and prophylactic kyphoplasty. Silicon derivatives are apparently not recommendable as candidate materials for kyphoplasty.
预防性椎体后凸成形术后人体骨质疏松性腰椎的生物力学研究。
与聚甲基丙烯酸甲酯骨水泥的性能相比，评估不同可吸收候选材料用于预防性椎体后凸成形术的潜在益处。
使用聚甲基丙烯酸甲酯骨水泥进行椎体后凸成形术以稳定骨质疏松性骨折椎体已成为一种有用的临床工具。在多项研究中，已报道在使用骨水泥强化的椎体尾侧或头侧的椎体出现连续压缩骨折。因此，一些医生已开始通过预防性强化来治疗相邻椎体。
对40个未骨折的人体骨质疏松性腰椎进行生物力学体外测试。在压缩和循环正弦测试期间评估三种类型的骨水泥（聚甲基丙烯酸甲酯、2种不同的磷酸钙骨水泥）和一种硅衍生物。每种候选材料在荧光镜控制下经双侧椎弓根应用。
材料不同的加工质量导致在骨水泥注入过程中存在显著差异，特别是在椎体的骨水泥填充量方面。然而，与天然椎体相比，强化后的标本显示出显著更高的压缩破坏强度。未记录到用聚甲基丙烯酸甲酯治疗的椎体与用任何一种磷酸钙骨水泥治疗的椎体之间存在显著差异。硅衍生物未能显著改善椎体的生物力学性能。
本研究表明，就体外力学性能而言，磷酸钙骨水泥与聚甲基丙烯酸甲酯骨水泥表现相同。因此，从力学角度来看，除聚甲基丙烯酸甲酯骨水泥外，磷酸钙骨水泥也可用于椎体后凸成形术和预防性椎体后凸成形术。硅衍生物显然不推荐作为椎体后凸成形术的候选材料。
