Badhiwala Jetan H, Platt Andrew, Witiw Christopher D, Traynelis Vincent C
Division of Neurosurgery and Spinal Program, Department of Surgery, University of Toronto, Toronto, ON, Canada.
Section of Neurosurgery, Department of Surgery, University of Chicago, Chicago, IL, USA.
J Spine Surg. 2020 Mar;6(1):217-232. doi: 10.21037/jss.2019.12.09.
Anterior cervical discectomy and fusion (ACDF) is an effective treatment for cervical spondylosis. A limitation of ACDF is the risk of adjacent-segment degeneration (ASD), owing to arthrodesis of a motion segment. Cervical disc arthroplasty (CDA) has hence garnered significant attention; yet, compelling evidence of reduction in ASD requiring surgery is lacking. This systematic review and meta-analysis sought to compare long-term longitudinal adjacent-level operation rates with CDA versus ACDF.
An electronic literature search was conducted. Eligible studies were multi-center randomized controlled trials (RCTs) comparing CDA with ACDF for one- or two-level symptomatic cervical spondylosis. The primary outcome was adjacent-level operation. Index-level reoperation was a secondary outcome. Outcomes were evaluated at 1-year intervals from the index operation to last reported follow-up by random-effects meta-analyses.
Eleven RCTs met criteria. For one-level spondylosis, there was no difference in the rate of adjacent-level operation between CDA (2.3%) and ACDF (3.6%) at 2 years. However, a large difference favoring CDA became evident at 5 years and persisted at 7 years (4.3% 10.8%, P<0.001). Significantly fewer patients who underwent CDA required index-level reoperation at all time points out to 7 years (5.2% 12.7%, P<0.001). Similar to one-level operations, there was no significant difference in adjacent-level operations with two-level CDA (1.7%) versus two-level ACDF (3.4%) at 2 years. At 7 years, a significant difference favoring CDA became apparent (5.1% 10.0%, P=0.014). Two-level CDA resulted in fewer index-level reoperations out to 7 years (4.2% 13.5%, P<0.001).
In this meta-analysis, the short-term rate of adjacent-level operation was similar with CDA or ACDF. However, around 5 years, a statistically significant divergence emerged, where the rate of adjacent-level surgery rose steeply for ACDF. Index-level reoperations were less frequent with CDA in both the short- and long-term. These data indicate CDA may have a superior longevity to ACDF with regard to need for subsequent adjacent-level operation.
颈椎前路椎间盘切除融合术（ACDF）是治疗颈椎病的一种有效方法。ACDF的一个局限性是由于运动节段融合，存在相邻节段退变（ASD）的风险。因此，颈椎间盘置换术（CDA）受到了广泛关注；然而，缺乏令人信服的证据表明CDA能降低需要手术的ASD发生率。本系统评价和荟萃分析旨在比较CDA与ACDF的长期纵向相邻节段手术率。
进行电子文献检索。符合条件的研究为多中心随机对照试验（RCT），比较CDA与ACDF治疗单节段或双节段症状性颈椎病的效果。主要结局是相邻节段手术。索引节段再次手术是次要结局。通过随机效应荟萃分析，从索引手术到最后一次报告的随访，每隔1年评估一次结局。
11项RCT符合标准。对于单节段颈椎病，2年时CDA组（2.3%）和ACDF组（3.6%）的相邻节段手术率无差异。然而，在5年时有利于CDA的显著差异变得明显，并在7年时持续存在（4.3%对10.8%，P<0.001）。在7年的所有时间点，接受CDA治疗的患者需要索引节段再次手术的人数显著减少（5.2%对12.7%，P<0.001）。与单节段手术类似，双节段CDA组（1.7%）与双节段ACDF组（3.4%）在2年时的相邻节段手术无显著差异。在7年时，有利于CDA的显著差异变得明显（5.1%对10.0%，P=0.014）。双节段CDA在7年时导致索引节段再次手术的人数减少（4.2%对13.5%，P<0.001）。
在这项荟萃分析中，CDA和ACDF相邻节段手术的短期发生率相似。然而，在大约5年时，出现了统计学上的显著差异，ACDF的相邻节段手术率急剧上升。CDA在短期和长期的索引节段再次手术都较少。这些数据表明，在后续相邻节段手术需求方面，CDA可能比ACDF具有更好的长期效果。
