Analysis of 2- and 7-year outcomes from a clinical trial comparing 2-level cervical disk arthroplasty (CDA) to anterior cervical discectomy and fusion (ACDF) in 287 patients with radiculopathy alone, and 110 patients with myelopathy alone or myelopathy with radiculopathy.
To compare the long-term safety and effectiveness of CDA for myelopathy versus radiculopathy.
CDA for myelopathy is safe and effective in short term.
We analyzed Neck Disability Index (NDI), neck/arm pain, SF-36, neurological status, adverse events (AEs), and secondary surgeries at index and adjacent levels.
All groups improved significantly for NDI, neck/arm pain, and physical component summary (PCS) scores from preoperative to postoperative. CDA Myelopathy versus CDA Radiculopathy: 2- and 7-year improvements were not significantly different. The 7-year score improvements for CDA Myelopathy and CDA Radiculopathy were: NDI (37.8 vs. 35.8, P=0.352), neck pain (12.0 vs. 12.1, P=0.477), arm pain (11.6 vs. 9.6, P=0.480), and PCS (14.1 vs. 13.7, P=0.863). The 2 groups had similar proportions of patients who maintained or improved their neurological status (87.2% vs. 93.5%, P=0.218), similar rates of serious AEs (54.5% vs. 57.5%, P=0.291) and similar rates of secondary surgeries at index (3.7% vs. 4.4%, P=0.839) and adjacent levels (3.7% vs. 7.6%, P=0.367). CDA Myelopathy versus ACDF myelopathy: 2 and 7-year improvements were not significantly different. The 7-year CDA and ACDF score improvements were: NDI (37.8 vs. 31.1, P=0.147), neck pain (12.0 vs. 10.4, P=0.337), arm pain (11.6 vs. 11.4, P=0.791), and PCS (14.1 vs. 11.2, P=0.363). The 2 groups had statistically similar proportions who maintained or improved their neurological status (87.2% vs. 96.2%, P=0.409), statistically similar overall rates of secondary surgeries at the index levels (3.7% vs. 9.4%, P=0.374), and statistically similar rates of secondary surgeries at adjacent levels (3.7% vs. 15.4%, P=0.088). CDA group demonstrated lower rates of serious AEs than ACDF (54.5% vs. 65.9%, P=0.019).
CDA for myelopathy is a safe and effective long-term treatment.
*The Orthopedic Center of St. Louis, St Louis, MO
†OAA Orthopaedic Specialists, Allentown, PA
‡Department of Orthopaedic Surgery, Columbia University Medical Center, New York, NY
§California Spine Group, Century City Hospital, Los Angeles, CA
∥Wilderness Spine Services, Columbus, GA
¶Center for Sports Medicine and Orthopedics, Chattanooga, TN
#Central Texas Spine Institute, Austin, TX
**SPIRITT Research, St. Louis, MO
This investigational device exemption and postapproval studies were sponsored by Medtronic (Memphis, TN).
M.F.G.: Consulting: Aesculap and Medtronic; Stockownership: Bonovo, International Spine & Orthopedic Institute, LLC, Nocimed, OuroBoros, Paradigm Spine; Royalties: Medtronic and RTI. J.R.M.: Consulting: Globus Medical Inc. and Zimmer-Biomet; Stockownership: Globus Medical Inc.; Royalties: Globus Medical Inc.; Research support: Medtronic; Speaker bureau: Zimmer-Biomet and Institute for Musculoskeletal Education. K.D.R.: Consulting: Medtronic; Royalties: Medtronic; Speaker bureau: Medtronic. T.H.L.: Consulting: Medtronic and Choice Spine; Royalties: Medtronic, Zimmer-Biomet, Nuvasive, and Choice Spine. J.K.B.: Consulting: Medtronic and Zimmer-Biomet; Royalties: Zimmer-Biomet; Research support: Medtronic and Nuvasive. S.D.H.: Speaker bureau: Medtronic. R.F.D.: Consulting: Lifespine; Royalties: Nuvasive, Globus Medical Inc., and Innovasis. F.W.S.: Stockownership: Nocimed. A.G.C. declares no conflict of interest.
Reprints: Matthew F. Gornet, MD, The Orthopedic Center of St. Louis, 14825 N. Outer Forty Road, Suite 200, St. Louis, MO 63141 (e-mail: mfgspine@gmail.com).
Received April 3, 2018
Accepted September 21, 2018
