Department of Orthopaedic Surgery, University of California San Diego, and Orthopedic Biomechanics Research Center, Rady Children's Hospital and Health Center, San Diego, CA, USA.
Spine (Phila Pa 1976). 2010 Sep 1;35(19):1783-8. doi: 10.1097/BRS.0b013e3181b7cc5d.
In vitro biomechanical investigation.
To evaluate differences in biomechanical stability of vertebral compression fractures repaired using balloon kyphoplasty versus a titanium mesh implant.
Vertebral compression fractures may be stabilized using an expandable balloon followed by cement injection. There are small but finite risks of endplate fracture and cement extravasation with this procedure. Alternative techniques may affect cement injection volumes, height maintenance, and biomechanical stability but require investigation.
Four male human cadaveric spines from T2 to L5 were used in this study. After determining bone mineral density, individual vertebral bodies were dissected and inspected for previous fractures or additional exclusion criteria. In the remaining vertebral bodies (n=48) anterior wedge fractures were created using a materials testing machine. Fractured vertebral bodies were systematically randomized to be repaired either with balloon kyphoplasty or with titanium mesh implant and polymethylmethacrylate bone cement, using image intensified fluoroscopy. Anterior vertebral body height (cm) was measured initially, after mechanically creating an anterior wedge fracture, after repairing the compression fracture with either technique, and after recompressing the vertebral body following a 24-hour cement polymerization period. Data for cement injection volume (mL) and height maintained following testing (cm) were compared between repair groups using a 1-way analysis of variance (P<0.05). Data for stiffness (N/mm), yield load (N), and ultimate load (N) were compared between intact bodies and repaired bodies using a 2-way analysis of variance (P<0.05).
There was significantly less cement injected (P<0.001) and significantly greater height maintained (P<0.025) with the titanium implant group compared to the kyphoplasty group. There were no significant differences in biomechanical stability between the 2 groups (P>0.05).
The titanium implant was biomechanically equivalent to the kyphoplasty repair while necessitating less cement and providing greater height maintenance in vitro. Improvements in pain and function could not be specifically addressed in this in vitro study and should be evaluated in a clinical case series.
体外生物力学研究。
评估球囊椎体后凸成形术与钛网植入物修复椎体压缩性骨折的生物力学稳定性差异。
可使用可膨胀球囊扩张椎体后注入骨水泥稳定椎体压缩性骨折。该手术存在极小的终板骨折和水泥外渗风险。替代技术可能会影响骨水泥注射量、高度维持和生物力学稳定性，但需要进一步研究。
本研究共使用了 4 具从 T2 到 L5 的男性人体尸体脊柱。在确定骨密度后，将每个椎体解剖并检查是否有先前的骨折或其他排除标准。在剩余的椎体（n=48）中，使用材料试验机创建前楔形骨折。系统随机选择使用球囊椎体后凸成形术或钛网植入物和聚甲基丙烯酸甲酯骨水泥修复楔形骨折的椎体，使用影像增强透视。初始测量椎体前缘高度（cm），然后机械性创建前楔形骨折后、用任意一种方法修复压缩性骨折后、在聚合 24 小时后再次压缩椎体后再次测量。比较两种修复方法的骨水泥注射量（mL）和测试后维持的高度（cm），使用单向方差分析（P<0.05）。比较完整椎体和修复椎体的刚度（N/mm）、屈服载荷（N）和极限载荷（N），使用双向方差分析（P<0.05）。
与球囊椎体后凸成形术组相比，钛网植入物组的骨水泥注射量显著减少（P<0.001），维持的高度显著增加（P<0.025）。两组间生物力学稳定性无显著差异（P>0.05）。
钛网植入物在生物力学上与球囊椎体后凸成形术相当，而在体外需要更少的骨水泥，并且提供更高的高度维持。在这项体外研究中，无法特别评估疼痛和功能的改善，应该在临床病例系列中进行评估。
