299 - 7-year Reoperation Rates: Results of a Prospective, Randomized Clinica...

#299 7-year Reoperation Rates: Results of a Prospective, Randomized Clinical Trial: Cervical Total Disc Replacement vs. Fusion

General Session: Best Papers Session

Presented by: R. Delamarter


R.B. Delamarter (1)
J. Zigler (2)
D. Murrey (3)
M. Janssen (4)
J. Spivak (5)

(1) Spine Center, Cedars Sinai Medical Center, Dept of Surgery, Los Angeles, CA, USA
(2) Texas Back Institute Research Foundation, Plano, TX, USA
(3) OrthoCarolina Spine Center, Charlottee, NC, USA
(4) Spine Education and Research Institute, Denver, CO, USA
(5) NYU/Hospital for Joint Disease, New York, NY, USA


Background Context: Multiple level 1 studies (prospective, randomized clinical trials) have now shown Cervical Artificial Disc Replacement (C-ADR) to be equivalent if not superior to Anterior Cervical Discectomy and Fusion (ACDF). Additionally, 4 and 5 year follow up in these same studies has revealed three to four times higher reoperation rates in the fusion patients when compared to the C-ADR .

Purpose: The purpose of this study was to determine the reoperation rates at both the index level and adjacent levels at a minimum 7-year follow-up of the patient cohorts involved in the prospective, randomized Pro-Disc cervical IDE study ( Synthes Spine Company, L.P. West Chester PA.)

Study Design: This is an FDA- regulated IDE study of 345 patients, where 209 patients were randomized from August 2003 to October 2004 to either C-ADR or ACDF in a 1:1 ratio, and 136 non-randomized continued access patients . Thirteen investigational sites across the U.S. participated. After FDA approval in 2007, yearly follow up was mandated by the FDA out to 84 months.

Patient Sample: A total of 345 patients with single-level symptomatic cervical disc disease were included. Two hundred and nine were randomized to either ADR (103) or ACDF (106) . 136 patients met the same criteria but were not randomized, and were enrolled in the continued access cohort .

Outcome Measures/Methods: Any patient with a secondary cervical surgery at any level was considered a reoperation. All follow up visits included Neck Disability Index (NDI), SF-36 Health Survey, 10 cm Visual Analog Scale (Neck and Arm pain) and Radiographic evaluation.

Results: After 7 years, the anterior discectomy and fusion patients (ACDF) had a 17.0 % (18/106) reoperation rate. Of these, twelve (11.3 %) had adjacent level surgery .The randomized C-ADR cohort had a 6.8 % (7/103) reoperation rate with 5.8 % (6/103) having adjacent level surgery. Of the continued access patients 5.9 % (8/136) had reoperation, with 5 having adjacent level surgery (3.7 %).

Conclusions: This analysis of 7- year data represents the longest follow up to date of level 1 data comparing C-ADR to fusion. Fusion patients had a 17.0 % overall reoperation rate compared to 5.8 % for Artificial disc replacement. Adjacent level degeneration requiring reoperation occurred in 11.3 % of fusion and 4.6 % of artificial disc patients. Longer term follow up continues to suggest that disc replacement results in a decreased rate of reoperation when compared to fusion.