RT Journal Article
SR Electronic
T1 Adjacent Segment Pathology After Treatment With Cervical Disc Arthroplasty or Anterior Cervical Discectomy and Fusion, Part 1: Radiographic Results at 7-Year Follow-Up
JF International Journal of Spine Surgery
JO Int J Spine Surg
FD International Society for the Advancement of Spine Surgery
SP 269
OP 277
DO 10.14444/7036
VO 14
IS 3
A1 PIERCE D. NUNLEY
A1 EUBULUS J. KERR III
A1 DAVID A. CAVANAUGH
A1 PHILLIP ANDREW UTTER
A1 PETER G. CAMPBELL
A1 RISHI WADHWA
A1 KELLY A. FRANK
A1 KYLE E. MARSHALL
A1 MARCUS B. STONE
YR 2020
UL http://ijssurgery.com//content/14/3/269.abstract
AB Background: Adjacent segment pathology (ASP) remains a concern following treatment with cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF). Radiographic ASP (RASP) is ASP identified on imaging, which may or may not include clinical symptoms. The risk factors for development of RASP and its clinical effects remain controversial. In part 1 of a 2-part publication we evaluate the incidence and predictors of RASP as well as determine whether any association exists between RASP and patient-reported outcomes (PROs).Methods: 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. Multiple post hoc analyses were conducted on RASP as it related to demographics and patient outcomes. Kaplan-Meier estimates of time to Kellgren-Lawrence (K-L) grade 3/4 were calculated separately for all groups. Multivariate Cox proportional hazard models were used analyze whether RASP was associated with patient preoperative demographic characteristics and preoperative and postoperative radiographic characteristics. The association of RASP with PROs was analyzed using generalized estimating equations and matched, retrospective cohort analysis.Results: The incidence of grade 3/4 RASP was lower for patients treated with CDA when initial treatment was at 1 level (27% vs 47%, P < .0001) and at 2 levels (14% vs 49%, P < .0001). Kaplan-Meier estimates indicated significantly lower probability of grade 3/4 RASP over time for patients receiving CDA (P < .001). Treatment with ACDF, treatment of 1 level, higher age, body mass index, higher preoperative physical components score, and a lower Cobb angle were associated with elevated risk of grade 3/4 RASP. CDA was shown to be more effective than ACDF (64.4%; 95% CI = 50.9, 74.2; P < .0001) at preventing RASP.Conclusions: The incidence and risk of RASP is decreased when patients are treated with CDA compared with ACDF. Although the mechanism of CDA that generates this protective effect is not understood, PROs remain unaffected through 7 years despite changes in RASP.