Adjacent segment degeneration or disease after cervical total disc replacement: a meta-analysis of randomized controlled trials

Abstract

BackgroundAnterior cervical discectomy and fusion (ACDF) has been widely used in cervical spondylosis, but adjacent segment degeneration/disease (ASD) was inevitable. Cervical total disc replacement (TDR) could reduce the stress of adjacent segments and retard ASD in theory, but the superiority has not been determined yet. This analysis aimed that whether TDR was superior to ACDF for decreasing adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDis).MethodsA meta-analysis was performed according to the guidelines of the Cochrane Collaboration with PubMed, EMBASE, Cochrane Library and CBM (China Biological Medicine) databases. It included randomized controlled trials (RCTs) that reported ASDeg, ASDis, and reoperation on adjacent segments after TDR and ACDF. Two investigators independently selected trials, assessed methodological quality, and evaluated the quality of this meta-analysis using the grades of recommendation, assessment, development, and evaluation (GRADE) approach.ResultsEleven studies with 2632 patients were included in the meta-analysis. The overall rate of ASD in TDR group was lower than ACDF group (OR = 0.6; 95% CI [0.38, 0.73]; P < 0.00001). Both the incidence of ASDeg and the reoperation rate were statistically lower in the TDR group than in the ACDF group (OR = 0.58, P < 0.00001; OR = 0.52, P = 0.01, respectively). Subgroup analysis was performed according to the follow-up time and trial site; the rate of ASDeg was lower in patients underwent TDR no matter the follow-up time, and TDR tended to increase the superiority across time. The rate of ASDeg was also lower with TDR both in the USA and China (P < 0.0001, P = 0.03, respectively). But the cost-effectiveness result might be prone to neither of the two surgery approaches. According to GRADE, the overall quality of this meta-analysis was moderate.ConclusionsTDR decreased the rates of ASDeg and reoperation compared with that of ACDF, and the superiority may become more apparent over time. We cautiously and slightly suggest adopting TDR according to the GRADE but may not believe it excessively.Electronic supplementary materialThe online version of this article (10.1186/s13018-018-0940-9) contains supplementary material, which is available to authorized users.

Optimization of Three-Level Cervical Hybrid Surgery to Prevent Adjacent Segment Disease: A Finite Element Study

“…However, surgical fixation and fusion markedly alters the biomechanics of the spinal segments, often resulting in reduced range of motion (ROM) in the operated level. This results in a compensatory hypermobility that can lead to accelerated degenerative effects in the motion segments adjacent to the fusion (Lee et al, 2014;Kong et al, 2016;Alhashash et al, 2018;Xu et al, 2018). Artificial disc replacement (ADR) is an alternative to ACDF to treat cervical degenerative disc disease while preserving motion at the operated level to prevent adjacent segment degeneration (ASD) (Pickett et al, 2005;Chang et al, 2007;Upadhyaya et al, 2012;Gao et al, 2015).…”

Long‐term Results Comparing Cervical Disc Arthroplasty to Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials

“…A recent metaanalysis showed that there was no statistically significant difference in ASD between CDA and ACDF within 24-months' follow-up period, but ASD was significantly lower with an increase of follow-up duration in CDA 16 . In contrast, Xu et al 21 and Zhu et al 23 found that CDA was superior in reducing the ASD incident rate when compared with ACDF, and this superiority became more apparent over time 21 . Although these 3 studies 16,21,23 attempted to evaluate ASD and symptomatic ASD separately, the follow-up period was not separated clearly, and long-term results were weak.…”

“…A recent meta‐analysis showed that there was no statistically significant difference in ASD between CDA and ACDF within 24‐months’ follow‐up period, but ASD was significantly lower with an increase of follow‐up duration in CDA. In contrast, Xu et al . and Zhu et al .…”

“…To our knowledge, there have been several metaanalyses comparing CDA with ACDF. Most of them have included partial long-term results, but they were mixed up with short-term and mid-term results 5,[16][17][18][19][20][21][22][23] . Therefore, given the availability of newly published long-term results [28][29][30][31][32][33][34][35][36][37][38] , we performed this study.…”

“…In the past 20 years, a series of randomized controlled trials (RCT) have been conducted; however, the reported results are inconsistent and have great variability. Although a few systematic reviews have been performed, researchers have failed to reach an agreement owing to varied criteria 5,[16][17][18][19][20][21][22][23][24] . Nevertheless, there is an absence of pooling of long-term results in a comprehensive meta-analysis.…”