Motion preservation in cervical spine: review.

Cervical disc replacement is an innovative technology that preserves motion at the instrumented level and has evolved as a potential alternative to spinal fusion for the treatment of cervical radiculopathy and myelopathy. Despite the excellent results of anterior cervical discectomy and fusion, arthroplasty allows for motion preservation which may be beneficial. Although the initial and midterm results from the randomized clinical trials demonstrated safety and equivalent clinical success as compared to anterior cervical fusion; the evidence establishing the superiority of arthroplasty over fusion in terms of preventing adjacent segment degeneration/disease is not available at this time.