Prospective Multicenter Trial of Cervical Arthroplasty with the ROTAIO? Cervical Disc Prosthesis

Study design: Clinical observational study. Objective: The ROTAIO (R) cervical disc prosthesis is a novel unconstrained implant with a variable center of rotation aiming at physiological motion. The objective of this multicenter prospective trial was to evaluate clinical outcome and complications within 2 years. Material and Methods: 120 patients (72 females and 48 males with median age of 43.0 years [23-60 yrs] underwent ACDA (ROTAIO (R), SIGNUS Medical, Alzenau, Germany) and were prospectively followed for 24 months. Preoperative complaints were mainly associated with radiculopathy (n = 104) or myelopathy (n=16). There were 108 monosegmental and 12 bisegmental procedures including 6 hybrid constructs. Clinical outcome was evaluated at 3, 12 and 24 months in 100%, 96% and 77% of the cohort by VAS, NDI, WL-26, Patient's Satisfaction Index (PSI), SF-36, Nurick Score, mJOA, Composite Success Rate, complications, patient's overall satisfaction and analgesics use. Results: Highly significant clinical improvements were observed according to NDI and VAS (P < .0001 (arm); P < .001 (neck); P = .002 (head)) at all time points. Analgetic use could be reduced in 87.1 to 95.2%. Doctor's visits have been reduced in 93.8% after 24 months. Patient's overall satisfaction was high with 78.4 to 83.5% of patients. The composite success rate was 77.5% after 12 months and 76.9% after 24 months. There were no major complications in this series. Slight subsidence of the prosthesis was observed in 2 patients and 3 patients demonstrated fusion after 24 months. 2 patients developed symptomatic foraminal stenosis, so that implant removal and fusion was performed resulting in a revision rate of 1.7% in 2 years. Conclusion: The ROTAIO (R) cervical disc prosthesis is a safe and efficient treatment option for symptomatic degenerative disc disease demonstrating highly significant clinical improvement and high patient's overall satisfaction with very low revision rates at 2 years.