Nunley Pierce D, Kerr Eubulus J, Cavanaugh David A, Utter Phillip Andrew, Campbell Peter G, Wadhwa Rishi, Frank Kelly A, Marshall Kyle E, Stone Marcus B
Spine Institute of Louisiana, Shreveport, Louisiana.
Int J Spine Surg. 2020 Jun 30;14(3):278-285. doi: 10.14444/7037. eCollection 2020 Jun.
Adjacent segment pathology (ASP) following cervical disc arthroplasty (CDA) or anterior cervical discectomy and fusion (ACDF) is identified by imaging (RASP) or clinical symptoms (CASP). Clinical symptoms of CASP have been broadly defined, but subsequent adjacent-level surgeries are clear indicators of CASP. Current literature remains inconsistent in the incidence and potential predictors of CASP. Here, we will evaluate a robust data set for the incidence of CASP resulting in subsequent surgery, attempt to identify factors that might affect CASP, and analyze the association of CASP with patient-reported outcomes (PROS) and RASP.
Data were prospectively collected during a US Food and Drug Administration randomized, multicenter, investigational device exemption trial comparing CDA (Mobi-C, Zimmer Biomet, Westminster, CO) with ACDF. CASP was defined as any adjacent-level subsequent surgical intervention. Post hoc analyses were conducted on the incidence, time to CASP diagnosis, and relationship of CASP with patient demographics. Longitudinal retrospective case-control analysis was used to assess the correlation of CASP to PROs and radiographic adjacent segment pathology (RASP).
Kaplan-Meier estimates indicated significantly lower probability of CASP over time for 1-level ( = .002) and 2-level ( = .008) CDA patients. Treatment with ACDF and younger age were associated with higher CASP risk. CDA was more effective than ACDF (70.5%; 95% CI = 45.1, 84.2; < .0001) at preventing CASP. Case-control analysis indicated increased probability of CASP for patients with grade 3/4 RASP, but the difference was not statistically significant. When we pooled CASP patients, the median grade of RASP at the visit prior to surgery was 1, with only 6 patients presenting with grade 3/4 RASP.
Patients treated with CDA have a lower incidence of CASP than do patients treated with ACDF, although the mechanism remains unclear. CASP and RASP remain uncorrelated in this large data set, but other predictive variables such as treatment, age, and number of levels should be further investigated.
颈椎间盘置换术（CDA）或颈椎前路椎间盘切除融合术（ACDF）后的相邻节段病变（ASP）可通过影像学检查（RASP）或临床症状（CASP）来识别。CASP的临床症状已有广泛定义，但随后的相邻节段手术是CASP的明确指标。目前的文献在CASP的发生率和潜在预测因素方面仍不一致。在此，我们将评估导致后续手术的CASP发生率的可靠数据集，试图确定可能影响CASP的因素，并分析CASP与患者报告结局（PROS）和RASP之间的关联。
在美国食品药品监督管理局的一项随机、多中心、研究器械豁免试验中前瞻性收集数据，该试验比较了CDA（Mobi-C，Zimmer Biomet，威斯敏斯特，科罗拉多州）与ACDF。CASP被定义为任何相邻节段的后续手术干预。对CASP的发生率、诊断时间以及CASP与患者人口统计学特征的关系进行事后分析。采用纵向回顾性病例对照分析来评估CASP与PROS以及影像学相邻节段病变（RASP）的相关性。
Kaplan-Meier估计表明，1节段（P = 0.002）和2节段（P = 0.008）CDA患者随着时间推移发生CASP的概率显著更低。ACDF治疗和年轻与更高的CASP风险相关。在预防CASP方面，CDA比ACDF更有效（70.5%；95%可信区间 = 45.1，84.2；P < 0.0001）。病例对照分析表明，3/4级RASP患者发生CASP的概率增加，但差异无统计学意义。当我们汇总CASP患者时，术前就诊时RASP的中位分级为1级，只有6例患者表现为3/4级RASP。
接受CDA治疗的患者发生CASP的发生率低于接受ACDF治疗的患者，尽管其机制尚不清楚。在这个大型数据集中，CASP与RASP仍然不相关，但其他预测变量，如治疗、年龄和节段数，应进一步研究。
