@article {GoldsteinS36, author = {Zachary H Goldstein and Barrett Boody and Rick Sasso}, title = {Two-Level Anterior Cervical Discectomy and Fusion Versus Cervical Disc Arthroplasty{\textemdash}Long-Term Evidence Update}, volume = {14}, number = {s2}, pages = {S36--S40}, year = {2020}, doi = {10.14444/7089}, publisher = {International Journal of Spine Surgery}, abstract = {Background: Multiple studies have highlighted the motion-sparing benefits of single-level cervical disc arthroplasty (CDA) compared with anterior cervical discectomy and fusion (ACDF). However, few studies have reviewed multilevel ACDF versus CDA. Several recent studies have midterm and even long-term data available comparing 2-level ACDF versus CDA.Methods: We reviewed 3 reports from 2 large randomized, prospective Food and Drug Administration investigational drug exemption trials looking at 2-level CDA versus ACDF, which provide the bulk of the available midterm to long-term, high-level evidence for the topic. We also present several smaller and/or shorter-term studies.Results: One 5-year study showed that, while both CDA and ACDF showed significant improvement in patient-reported outcome scores, CDA demonstrated greater improvement in Neck Disability Index (NDI) scores than ACDF (mean = -37 versus mean = -28, P = .0003), were more likely to be satisfied (96.4\% versus 89.5\%, P = .04), had fewer secondary surgeries (4\% versus 16.2\%, P = .0003), had fewer adjacent level reoperations (3.1\% versus 11.4\%), and developed less adjacent segment degeneration (50.7\% versus 90.5\%, P \< .0001). Adverse events occurred more frequently with ACDF (8.6\% versus 4.4\%).Similarly, Lanman et al [Lanman TH, Burkus JK, Dryer RG, Gornet MF, McConnell J, Hodges SD. Long-term clinical and radiographic outcomes of the Prestige LP artificial cervical disc replacement at 2 levels: results from a prospective randomized controlled clinical trial. J Neurosurg Spine. 2017;27(1):7{\textendash}19] showed that, at 7 years, while both groups demonstrated improvement in patient-reported outcomes, CDA had greater improvement in regard to NDI, neck pain, and Short Form (36) Physical Component Summary scores (each P \< .001), had higher rates of satisfaction (94.8\% versus 92.6\%), had lower rate of secondary surgery at treated levels (4.2\% versus 14.7\%), and had a lower, albeit not statistically significant, rate of secondary surgeries at adjacent levels (6.5\% versus 12.5\%). Adverse events were more common with ACDF (7.2\% versus 3.2\%).More recently, Gornet et al [Gornet MF, Lanman TH, Burkus JK, et al. Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial. J Neurosurg Spine. 2019;31:508{\textendash}518.] in 2019 reported 10-year data from the same clinical trial as the Lanman et al report comparing 2-level CDA (209 patients) versus ACDF (188 patients). With \>84\% follow-up for both groups at 10 years, they found that CDA demonstrated a statistically significantly improved rate of overall success (84\% versus 62\%) as compared with ACDF. Greater improvements were seen in several other outcome measures for CDA, including NDI, neurological success, and neck pain scores. The CDA group had a lower rate of serious implant-related adverse events and demonstrated a lower rate of needing a secondary surgery at an adjacent level, 9\% versus 18\% in the ACDF group.Conclusions: Results of 2 large randomized trials suggest similar-to-improved patient reported outcomes for multilevel CDA versus ACDF maintained out to midterm to long-term follow-up of 5{\textendash}10 years, with lower rates of revision surgery at index and adjacent levels and lower rates of serious adverse device-related events.Level of Evidence: 5.Clinical Relevance: Comparison of the safety and efficacy of multi-level cervical disc arthroplasty and cervical discectomy and fusion.}, issn = {2211-4599}, URL = {http://www.ijssurgery.com/content/14/s2/S36}, eprint = {http://www.ijssurgery.com/content/14/s2/S36.full.pdf}, journal = {International Journal of Spine Surgery} }