The Norwegian Cervical Arthroplasty Trial

Inclusion Criteria: * Age 25 - 60 years * Clinical C6 or C7 root radiculopathy with corresponding radiologic findings with or without neurological symptoms * Mechanical provoked pain which aggravate with physical activity or positive Spurling test * Radiological nerve root compression on the basis of disc herniation or spondylosis * NDI =/\> 30 percent * The patient has not responded to non-operative treatment and shown no sign of improvement during the last 6 weeks Exclusion Criteria: * Significant spondylosis involving more than one level * Intramedullary changes on MRI * Ankylosis at adjacent level * Clinical suspicion of myelopathy * Chronic generalised pain syndrome * Infection * Active cancer * Rheumatoid arthritis involving the cervical spine * Previous trauma involving the cervical spine * Pregnancy * Allergy against contents in cage/artificial disc * Previous neck surgery * Psychological or somatic illness that causes the patient not to be suitable for the study * The patient does not understand Norwegian orally or in writing. * Abuse of medication/narcotics