General Session: Cervical-2
Presented by: M. Hisey - View Audio/Video Presentation (Members Only)
M. Hisey(1), H. Bae(2), D. Ohnmeiss(3)
(1) Texas Back Institute, Denton, TX, United States
(2) Cedars-Sinai Spine Center, Los Angeles, CA, United States
(3) Texas Back Institute Research Foundation, Plano, TX, United States
Introduction: Anterior cervical discectomy and fusion (ACDF) has been a widely accepted procedure for years. There has been variation in reported results for two-level ACF. Cervical disc arthroplasty (CDA) has been gaining acceptance for single-level treatment and more data is becoming available for two-level. The purpose of this analysis was to compare the safety and effectiveness of one and two level treatment with CDA or anterior cervical discectomy and fusion (ACDF).
Methods: A prospective, randomized, controlled trial in the U.S. compared CDA using Mobi-C© Cervical Disc Prosthesis and the ACDF control with allograft and anterior plate at one or two contiguous levels. The one-level arm consisted of 164 CDA and 81 ACDF patients. The two-level arm consisted of 225 CDA and 105 ACDF patients. Outcome assessments including the Neck Disability Index (NDI), visual analog scale (VAS) assessing neck and arm pain, range of motion (ROM), patient satisfaction, SF-12 mental and physical composite scores (MCS/PCS), and subsequent surgery rates were recorded through 60 month follow-up.
Results: Combined five-year follow-up rate was 88.5% for CDA and 83.1% for ACDF. No significant differences were found between one and two-level treatment in VAS neck and arm pain, SF-12 MCS, subsequent surgery rates, or patient satisfaction for TDR and ACDF, respectively. Two-level ACDF patients demonstrated less improvement in NDI (p< 0.01; Figure 1) and SF-12 PCS (1-level: 14.0, 2-level: 8.8, p>0.010) scores compared to one-level ACDF. Additionally, the NDI success rate was significantly lower for two-level ACDF (1-level: 80.7%, 2-level: 56.6%, p< 0.05). However, no significant differences were found between one and two-level CDA in NDI success, mean improvement in NDI or SF-12 PCS scores. When considering index level re-operations through 5-year follow-up, the highest rate was in the 2-level ACDF group (16.2%), followed by 11.1% in the 1-level ACDF group compared with 3.0% and 4.0% in the 1- and 2-level CDA groups.
Discussion: At five years, one and two-level CDA patients showed no significant differences in clinical outcomes. In contrast, two-level ACDF patients demonstrated less NDI improvement, less SF-12 PCS improvement and lower NDI success than their one-level ACDF counterparts. These results suggest that CDA has potential benefits over ACDF, particularly for 2-level procedures.
Figure 1. Mean NDI scores.