A nonrandomized, prospective, and single-center clinical trial of the ProDisc Vivo prosthesis.
The aim of this study was to investigate the clinical and radiological results of a refined total cervical disc replacement (cTDR), the ProDisc Vivo, with two years of follow-up (FU). The incidence of implant-related complications was recorded as a secondary outcome variable.
Previous generations of the ProDisc artificial cervical disc replacement generate high primary stability due to keel-based designs with opening of the anterior cortex during the implantation and subsequent high rates of heterotopic ossifications.
Clinical outcome scores included the Neck Disability Index (NDI), Visual Analogue Scale (VAS), arm and neck pain self-assessment questionnaires. The radiological outcome included the range of motion (ROM) and the occurrence of heterotopic ossifications. The incidence of implant-related complications with new implant design was recorded as a secondary outcome variable.
A total of 55 patients received a single-level treatment with the ProDisc Vivo cTDR between C3/4 and C6/7, with a follow-up rate of 78%. The clinical outcome scores improved in all parameters significantly (P = 0.0001) (NDI: 68.3 → 17.4; VAS arm: 6.3 → 1.4; VAS neck: 4.9 → 1.6). The ROM of the index-segment did not show a significant change (P = 0.26) (7.9° → 9.2°). Heterotopic ossifications at the index segment was found as grade 0 in 58%, grade 1 in 22%, grade 2 in 10%, grade 3 (with functional impairment of the prosthesis) in 7%, and grade 4 in 3% of the cases. We observed three implant-related complications (5.5%), with two implant dislocations anteriorly and one low-grade infect.
cTDR with ProDisc Vivo demonstrated a significant and sustained improvement of all clinical outcome parameters. A less invasive implantation mechanism with lower primary stability of the cTDR might be a reason for a higher dislocation rate than the keel-based previous generation ProDisc C.
Level of Evidence: 4
Within a non-randomized prospective and single center clinical trial 55 patients received a single level treatment with the ProDisc Vivo. The clinical parameters improved significantly over time. Anterior dislocation of the prosthesis was seen in 2 cases as indicator for unsufficient primary stability of the less-invasive implantation mechanisms.
∗Schön Klinik München Harlaching, Spine Center, Munich, Germany
†Academic Teaching Hospital and Spine Research Institute, Paracelsus Medical University, Salzburg, Austria
‡Schön Klinik Eilbeck, Clinic for Spinal Surgery, Hamburg, Germany
§Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
¶Research Office - Biostatistics, Paracelsus Medical University, Salzburg, Austria
||Department of Ophthalmology and Optometry, Paracelsus Medical University, Salzburg, Austria
∗∗Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
††Department of Health Sciences, University of Potsdam, Potsdam, Germany.
Address correspondence and reprint requests to Christoph Mehren, MD, Schön Clinic Munich Harlaching, Harlachinger Str. 51, 81547 Munich, Germany; E-mail: CMehren@schoen-kliniken.de
Received 29 March, 2018
Revised 22 June, 2018
Accepted 28 June, 2018
The device(s)/drug(s) that is/are the subject of this manuscript is/are not FDA-approved for this indication and is/are not commercially available in the United States.
No funds were received in support of this work.
No relevant financial activities outside the submitted work.