Introduction: A next generation cervical disc replacement which mimics the natural disc structure and its biomechanical qualities is being evaluated in a FDA IDE clinical trial. Unlike ball-and-socket cervical discs, this next generation cervical disc allows the motion inherent in a natural disc including axial compression, flexion-extension, lateral bending, translation, and axial rotation.
Methods: The two centers participated in a prospective, multi-center, FDA IDE study of subjects with cervical radiculopathy who had not improved with conservative care of at least six-weeks. Skeletally mature subjects were implanted with the cervical disc at one-level from C3 - C7. Subjects were required to have preoperative neck or arm pain Visual Analogue Scales (VAS) = 4, Neck Disability Index (NDI) = 30% and other entry requirements similar to prior cervical disc FDA IDE studies.
Results: Thirty-three subjects were implanted. The mean age was 44 years, and 19 were males. Ninety-one percent were implanted in the C5 to C7 levels. Mean surgical time was 78 minutes, and mean hospital stay was one day. Mean preoperative NDI was 59 which decreased to 14 (p<0.0001) at two-years. VAS neck pain was reduced from 7.2 preoperative to 1.3 (p<0.0001) at two-years, and mean predominant preoperative arm VAS pain was 7.1 versus 0.7 (p<0.0001) at two-years. There have been no discs revised or removed. One subject experienced minimal caudal subsidence by two-years. No radiolucencies or migrations were reported. Mean index level ROM was 9.3 degrees preoperative versus 8.4 degrees at two-years, and mean index level disc angle improved from 3.6 preoperative to 8.1 degrees at two-years. Mean disc height increased at two-years to 5.5 mm vs 3.2 mm preoperative.
Conclusions: The early results for the cervical disc arthroplasty subjects implanted at the two centers with a next generation cervical disc design demonstrate good clinical outcomes.
Patient Care: This new design demonstrates the next generation of cervical artificial disc offers physiologic axial load compression in addition to the other ROM and has application to clinical practice offering good clinical outcomes.
Learning Objectives: The objective of this study was to determine the safety and effectiveness outcomes of a cervical next generation arthroplasty at 2 years follow up.