Patients are candidates for single-level Artificial Disc Replacement between C3 and C7 who suffer from cervical symptomatic degenerative disc disease. A maximum of 200 cases will be enrolled into the study. An 18-month recruitment period is planned with a 4-year postoperative follow-up period for each subject. Thus, it is anticipated that the study will require a minimum of 5.5 years. Patients will be assessed preoperatively, intraoperatively, prior to discharge and again at 6 weeks, 6 months, 1 year, 2 years and 4 years postoperatively from the date of surgery.

The activ C Disc Prosthesis pursues the goal of restoring the disc function, the geometry and motion of the cervical disc. Its concept is based on a ball and socket joint, anchored between adjacent vertebral bodies. The modular prosthesis comprises the following elements: an inferior CoCr plate component anchored in the endplate of the caudal vertebral body. The UHMWPE inlay is securely fixed in this inferior component. The second element is the superior CoCr component, which is anchored in the end plate of the cranial vertebral body. It forms a ball joint with the inlay of the inferior plate component.

The activ C product range enables reconstruction of various disc heights as well as adaptation to the end plate sizes. Secure primary anchorage of the prosthesis to the vertebral bodies is achieved by convexly shaped superior end pla tes and fixation means (spikes and grooves on the superior end plate, a small keel on the inferior end plate), whereas secondary stability is facilitated by an osseointegrative Plasmapore® coating.

The objective of the study is to collect outcome information on the Activ® C Disc Prosthesis.

Inclusion Criteria:

• Symptomatic single-level cervical degenerative disc disease with neck and/or arm
• pain and/or neurological deficit, confirmed by MR scan
• Single-level surgery and single-level implantation of prosthesis between C3 and C7
• Age between 18 - 65 years at the time of surgery
• Pre-operative disc space height of the segment to be operated of at least 3mm
• Unsuccessful adequate conservative treatment
• Patient understands the conditions of the study and is willing and able to comply with the post-operative scheduled clinical and radiographic evaluations and the prescribed rehabilitation
• Patient signed Informed Consent

Exclusion Criteria:

• Major facet joint degeneration at the segment to be operated on
• Severe spondylosis at the segment to be operated on (bridging osteophytes, absence of motion (<2°))
• Pre-operative disc space height of the segment to be operated on of less than 3mm
• Major cervical segmental instability at the segment to be operated on (translation ≥3,5 mm and/or ≥11° of rotational difference to that of either adjacent level)
• Previous trauma to the segment to be operated on resulting in compression or bursting

adult patients