Achatz Gerhard, Riesner Hans-Joachim, Friemert Benedikt, Lechner Raimund, Graf Nicolas, Wilke Hans-Joachim
Department of Orthopedics and Trauma Surgery, Reconstructive and Septic Surgery, Sportstraumatology, Trauma Research Group, German Armed Forces Hospital Ulm, Oberer Eselsberg 40, 89081, Ulm, Germany.
SpineServ GmbH & Co. KG, Söflinger Strasse 100, 89077, Ulm, Germany.
Eur Spine J. 2017 Dec;26(12):3225-3234. doi: 10.1007/s00586-017-5035-5. Epub 2017 Apr 27.
Balloon kyphoplasty (BK) has emerged as a popular method for treating osteoporosis vertebral compression fractures (OVCFs). In response to several shortcomings of BK, alternative methods have been introduced, among which is radiofrequency kyphoplasty (RFK). Biomechanical comparisons of BK and RFK are very sparse. The purpose of this study was to perform a biomechanical study in which BK and RFK are compared.
Each of the two study groups comprised six specimens prepared from two functional spinal units (FSUs) cut from fresh-frozen cadaveric spines (3 of T9-T11 and 3 of T12-L2). VCFs (A1.2 type) were created in the middle VB of each of the FSUs, with a height loss of 30% of the VB. After that, the specimens were subjected to cyclic compression-compression loading. The following parameters were determined: range of motion (ROM), height of the middle VB, augmentation time, cement interdigitation and cement distribution. Also, the cement layer, the trabecular bone in the augmented VB and the bone-cement interface were examined for cracks. All of these parameters were determined at various stages, namely in the intact middle VB and after its fracture, cement augmentation and subject to the cyclic loading protocol.
Fractures caused a significant increase in median ROM and a significant reduction in the height of fractured VB. Cement augmentation significantly stabilized the fractures and led to partial height restoration. ROM and vertebral height, however, were not restored to the intact levels. Cyclic loading led to a further significant increase in ROM and a significant height reduction. There were no significant differences between BK and RFK in terms of any of these parameters.
BK and RFK achieved similar results for fracture stabilization and restoration of the height of the fractured VB. RFK involved shorter cement augmentation time and less damage to the trabecular bone.
球囊椎体后凸成形术（BK）已成为治疗骨质疏松性椎体压缩骨折（OVCFs）的常用方法。针对BK的若干缺点，已引入了替代方法，其中包括射频椎体后凸成形术（RFK）。BK和RFK的生物力学比较非常少。本研究的目的是进行一项比较BK和RFK的生物力学研究。
两个研究组每组均由六个标本组成，这些标本取自从新鲜冷冻尸体脊柱上切下的两个功能脊柱单元（FSU）（T9-T11节段3个，T12-L2节段3个）。在每个FSU的中间椎体（VB）制造OVCFs（A1.2型），使VB高度损失30%。之后，对标本进行循环压缩加载。测定以下参数：活动范围（ROM）、中间VB的高度、强化时间、骨水泥相互交指和骨水泥分布。此外，检查骨水泥层、强化VB中的小梁骨以及骨-骨水泥界面是否有裂缝。所有这些参数均在不同阶段测定，即在完整的中间VB中、骨折后、骨水泥强化后以及进行循环加载方案后。
骨折导致中位ROM显著增加，骨折VB的高度显著降低。骨水泥强化显著稳定了骨折并导致部分高度恢复。然而，ROM和椎体高度未恢复到完整水平。循环加载导致ROM进一步显著增加，高度显著降低。在这些参数的任何方面，BK和RFK之间均无显著差异。
BK和RFK在骨折稳定和恢复骨折VB高度方面取得了相似的结果。RFK的骨水泥强化时间较短，对小梁骨的损伤较小。
