Radcliff Kris, Davis Reginald J, Hisey Michael S, Nunley Pierce D, Hoffman Gregory A, Jackson Robert J, Bae Hyun W, Albert Todd, Coric Dom
Department of Orthopedic Surgery, Rothman Institute, Thomas Jefferson University, Egg Harbor, NJ.
Greater Baltimore Neurosurgical Associates, Baltimore, MD.
Int J Spine Surg. 2017 Nov 28;11(4):31. doi: 10.14444/4031. eCollection 2017.
Cervical total disc replacement (TDR) is an increasingly accepted procedure for the treatment of symptomatic cervical degenerative disc disease. Multiple Level I evidence clinical trials have established cervical TDR to be a safe and effective procedure in the short-term. The objective of this study is to provide a long-term assessment of TDR versus anterior discectomy and fusion for the treatment of one- and two-level disc disease.
This study was a continuation of a prospective, multicenter, randomized, US FDA IDE clinical trial comparing cervical TDR with the Mobi-C Cervical Disc versus ACDF through 7 years follow-up. Inclusion criteria included a diagnosis of symptomatic cervical degenerative disc disease at one or two cervical levels. TDR patients were treated using a Mobi-C artificial disc (Zimmer Biomet, Austin TX, USA). ACDF with allograft and anterior plate was used as a control treatment. Outcome measures were collected preoperatively and postoperatively at 6 weeks, at 3, 6, 12, 18 months, annually through 60 months, and at 84 months. Measured outcomes included Overall success, Neck Disability Index (NDI), VAS neck and arm pain, segmental range of motion (ROM), patient satisfaction, SF-12 MCS/PCS, major complications, and subsequent surgery rate. The primary endpoint was an FDA composite definition of success comprising clinical improvement and an absence of major complications and secondary surgery events.
A total of 599 patients were enrolled and treated, with 164 treated with one-level TDR, 225 treated with two-level TDR, 81 treated with one-level ACDF, and 105 treated with two-level ACDF. At seven years, follow-up rates ranged from 73.5% to 84.4% (overall 80.2%).The overall success rates of two level TDR and ACDF patients were 60.8% and 34.2%, respectively (p<0.0001). The overall success rates of one level TDR and ACDF patients were 55.2% and 50%, respectively (p>0.05). Both the single and two level TDR and ACDF groups showed significant improvement from baseline NDI scores, VAS neck and arm pain scores, and SF-12 MCS/PCS scores (p<0.0001). In the single level cohort, there was an increased percentage of TDR patients who reported themselves as "very satisfied" (TDR 90.9% vs ACDF 77.8%; p= 0.028). There was a lower rate of adjacent level secondary surgery in the single level TDR patients (3.7%) versus the ACDF patients (13.6%; p = 0.007).In the two level TDR group, the NDI success rate was significantly greater in the TDR group (TDR: 79.0% vs. ACDF: 58.0%; p=0.001). There was significantly more improvement in NDI change score at 7 years in the TDR patients versus ACDF. The TDR group had a significantly higher rate of patients who were "very satisfied" with their treatment compared to the ACDF group (TDR: 85.9% vs. ACDF: 73.9%). The rate of subsequent surgery at the index level was significantly lower in the TDR group compared to the ACDF group (TDR: 4.4% vs. ACDF: 16.2%; p=0.001). The rate of adjacent level secondary surgery was significantly lower in the two level TDR (4.4%) patients compared to the ACDF (11.3%; p=0.03) patients. In both single and two level cohorts, the percentage of patients with worse NDI (2.5%-3.8% of two level surgeries and 1.2%-2.5% of single level surgeries) or worse neck pain (5%-6.8% of the two level surgeries and 1.3% - 3.8% of the single level surgeries) was strikingly low in both groups but trended lower in the TDR patients.
At seven years, the composite success analysis demonstrated clinical superiority of two level TDR over ACDF and non-inferiority of single level TDR versus ACDF. There were lower rates of secondary surgery and higher adjacent level disc survivorship in both groups. Both surgeries were remarkably effective in alleviating pain relative to baseline and the rate of patients with worse disability or neck pain was surprisingly low. Overall, greater than 95% of patients (from both groups) who underwent TDR and 88% of patients who underwent ACDF were "very satisfied" at seven years. The differences in clinical effectiveness of TDR versus ACDF becomes more apparent as treatment increases from one to two levels, indicating a significant benefit for TDR over ACDF for two-level procedures.
The Mobi-C Clinical Trial (ClinicalTrials.gov registration number: NCT00389597) was conducted at 24 sites in the US and was approved by the Institutional Review Board, Research Ethics Committee, or local equivalent of each participating site.
颈椎全椎间盘置换术（TDR）是治疗有症状的颈椎退行性椎间盘疾病越来越被认可的一种手术。多项I级证据的临床试验已证实颈椎TDR在短期内是一种安全有效的手术。本研究的目的是对TDR与前路椎间盘切除融合术治疗单节段和双节段椎间盘疾病进行长期评估。
本研究是一项前瞻性、多中心、随机、美国食品药品监督管理局器械临床试验豁免（IDE）的临床试验的延续，该试验通过7年随访比较了颈椎TDR与Mobi-C颈椎间盘与ACDF。纳入标准包括诊断为单节段或双节段有症状的颈椎退行性椎间盘疾病。TDR患者采用Mobi-C人工椎间盘（美国德克萨斯州奥斯汀市的捷迈邦美公司）进行治疗。使用同种异体骨和前路钢板的ACDF作为对照治疗。术前及术后6周、3、6、12、18个月、每年直至60个月以及84个月时收集结果指标。测量的结果包括总体成功率、颈部功能障碍指数（NDI）、颈部和手臂疼痛视觉模拟评分（VAS）、节段活动度（ROM）、患者满意度、SF-12生理健康/心理健康评分、主要并发症以及后续手术率。主要终点是美国食品药品监督管理局对成功的综合定义，包括临床改善以及无主要并发症和二次手术事件。
共纳入并治疗了599例患者，其中164例行单节段TDR治疗，225例行双节段TDR治疗，81例行单节段ACDF治疗，105例行双节段ACDF治疗。7年时，随访率在73.5%至84.4%之间（总体为80.2%）。双节段TDR和ACDF患者的总体成功率分别为60.8%和34.2%（p<0.0001）。单节段TDR和ACDF患者的总体成功率分别为55.2%和50%（p>0.05）。单节段和双节段TDR及ACDF组的NDI评分、颈部和手臂疼痛VAS评分以及SF-12生理健康/心理健康评分与基线相比均有显著改善（p<0.0001）。在单节段队列中，报告自己“非常满意”的TDR患者比例增加（TDR为90.9%，ACDF为77.8%；p = 0.028）。单节段TDR患者的相邻节段二次手术率（3.7%）低于ACDF患者（13.6%；p = 0.007）。在双节段TDR组中，TDR组的NDI成功率显著更高（TDR：79.0%，ACDF：58.0%；p = 0.001）。TDR患者在7年时NDI变化评分的改善明显多于ACDF患者。与ACDF组相比，TDR组对治疗“非常满意”的患者比例显著更高（TDR：85.9%，ACDF：73.9%）。与ACDF组相比，TDR组在索引节段的后续手术率显著更低（TDR：4.4%，ACDF：16.2%；p = 0.001）。双节段TDR患者（4.4%）的相邻节段二次手术率显著低于ACDF患者（11.3%；p = 0.03）。在单节段和双节段队列中，两组中NDI更差（双节段手术的2.5%-3.8%和单节段手术的1.2%-2.5%）或颈部疼痛更差（双节段手术的5%-6.8%和单节段手术的1.3%-3.8%）的患者比例均极低，但TDR患者的这一比例有更低的趋势。
7年时，综合成功分析表明双节段TDR优于ACDF，单节段TDR与ACDF相当。两组的二次手术率更低，相邻节段椎间盘生存率更高。相对于基线，两种手术在缓解疼痛方面都非常有效，残疾或颈部疼痛更差的患者比例出奇地低。总体而言，接受TDR的患者（两组）中超过95%以及接受ACDF的患者中88%在7年时“非常满意”。随着治疗节段从单节段增加到双节段，TDR与ACDF临床疗效的差异变得更加明显，表明双节段手术中TDR比ACDF有显著优势。
Mobi-C临床试验（ClinicalTrials.gov注册号：NCT00389597）在美国24个地点进行，并获得了每个参与地点的机构审查委员会、研究伦理委员会或当地同等机构的批准。
1级。
