Kasliwal Manish K, Baskin David S, Traynelis Vincent C
Rush University Medical Center, Chicago, IL, USA.
J Spinal Disord Tech. 2013 Jul;26(5):239-45. doi: 10.1097/BSD.0b013e318241e70f.
The objective of this study was to assess the safety and efficacy of 2 novel cervical interbody fusion devices in the treatment of single-level degenerative cervical disk disease. Both devices were fabricated from a porous tantalum material. The high overall porosity of the devices was intended to facilitate anterior cervical interbody fusion.
A prospective, randomized, 3-armed, clinical study was initiated with the following treatment groups: porous tantalum ring device packed with autograft, porous tantalum block device, and iliac crest autograft control. All the patients had single-level symptomatic cervical disk disease that had failed to respond to nonoperative therapy. Clinical and radiographic data were collected preoperatively, during surgery, before hospital discharge, and at 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperatively.
Six investigators participated in the clinical study at 6 investigational centers in the United States. Enrollment into the study was terminated after 39 patients had been accrued because of concerns over delayed fusion in the porous tantalum treatment groups. Of the 39 patients enrolled into the clinical study, 11 patients received the control treatment of iliac autograft fusion, 13 patients received the porous tantalum ring device with the center cavity packed with cancellous iliac crest autograft, and 15 patients received the porous tantalum block device. These patients were evaluated for 24 months as per the study protocol. There were no significant differences in any of the patient demographic variables collected. The mean operative times for both the ring and block device groups were slightly lower than the control treatment. Two patients in the block treatment group were determined to be nonunion between the 6- and 12-month time points and underwent additional surgery. Five patients with porous tantalum devices showed radiographic evidence of device fragmentation, and one patient in addition had radiographic evidence of erosion of the involved vertebral bodies by the device. One patient in the ring treatment group died from a myocardial infarction and kidney failure subsequent to the 12-month follow-up visit, which was unrelated to the device or the spinal fusion procedure. Fusion rate at 2 years for the tantalum device was very low as compared with the control arm (44% vs. 100%). Patient Neck Disability Index scores, Short Form-36 scores, and neurological status scores were similar between the 3 treatment groups.
This study demonstrates that stand-alone porous tantalum material is not ideal for a cervical spine interbody fusion because of the low rate of arthrodesis and the risk of device fragmentation in patients who fail to fuse.
本研究的目的是评估两种新型颈椎椎间融合器治疗单节段退变性颈椎间盘疾病的安全性和有效性。两种融合器均由多孔钽材料制成。融合器的高整体孔隙率旨在促进颈椎前路椎间融合。
开展一项前瞻性、随机、三臂临床研究，设置以下治疗组：填充自体骨的多孔钽环装置、多孔钽块装置和髂嵴自体骨对照组。所有患者均患有单节段有症状的颈椎间盘疾病，且非手术治疗无效。在术前、手术期间、出院前以及术后6周、3个月、6个月、12个月和24个月收集临床和影像学数据。
6名研究者在美国的6个研究中心参与了该临床研究。由于担心多孔钽治疗组融合延迟，在纳入39例患者后终止了研究入组。在纳入临床研究的39例患者中，11例患者接受了髂骨自体骨融合的对照治疗，13例患者接受了中心腔填充松质髂骨自体骨的多孔钽环装置，15例患者接受了多孔钽块装置。按照研究方案对这些患者进行了24个月的评估。所收集的任何患者人口统计学变量均无显著差异。环装置组和块装置组的平均手术时间均略低于对照治疗组。块治疗组有2例患者在6至12个月时间点被判定为骨不连，并接受了额外手术。5例使用多孔钽装置的患者显示有装置碎裂的影像学证据，1例患者还显示有装置对受累椎体侵蚀的影像学证据。环治疗组有1例患者在12个月随访后死于心肌梗死和肾衰竭，这与装置或脊柱融合手术无关。与对照组相比，钽装置2年时的融合率非常低（44%对100%）。3个治疗组之间的患者颈部功能障碍指数评分、简明健康状况调查36项评分和神经功能状态评分相似。
本研究表明，单纯的多孔钽材料对于颈椎椎间融合并不理想，因为融合率低，且在未融合患者中有装置碎裂的风险。
