• show significant difference of degeneration of disc above and below the operated stage between the two groups [ Time Frame: 3 years after surgery ] [ Designated as safety issue: No ]
  

• show difference of neurological pain between the two groups [ Time Frame: during the 3 years of follow-up ] [ Designated as safety issue: No ]
  
• show difference of duration of hospitalization and consumption of medication [ Time Frame: during the first month after surgery ] [ Designated as safety issue: No ]
  

Anterior surgery of the cervical spine is one of the most practiced procedures in spine surgery. Its immediate accuracy and safety is proved since a long time in case of degenerative disk disease or disk herniation. But the segmental arthrodesis leads to an overload of the adjacent disk. A lot of studies have shown that the increasing mobility and pressure of the adjacent segments can be responsible of new degeneration and clinical symptoms. Recently, cervical disk prosthesis have been developed to maintain the mobility at the level of the surgery. This technique is supposed to decrease the risk of adjacent disk disease but, at this time, the analysis of the results is difficult, due to the lack of randomized studies with long term follow up.

The aim of our prospective randomized study is to evaluate the aftermath of the arthroplasty compared to the fusion on the adjacent disk degeneration.

The main objective is to show a radiological difference at 3 years in term of adjacent disk degeneration.

The secondary objectives are:

• evaluate the rate of new clinical symptoms during three years
• show differences during the postoperative period, especially concerning the length of the hospital stay, the use of pain killers and return to work.
• verify the maintaining of mobility pf the prosthesis during three years.

This is a controlled study with two group of equal size: one group is treated by discectomy and arthrodesis and the other by discectomy and prosthesis/ The criteria for the inclusion of the patients are: clinical radiculopathy and/or myelopathy due to a cervical disk disease (disk herniation or osteophytosis), lack of effect of the medical treatment, CT scan or MRI showing a compression of roots and/or spinal cord.

The main exclusion criteria are: plurisegmental disk disease, injuries happened during professional activities, previous cervical surgery.

During the study, we perform a clinical (standardized scales: Neck Disability Index, Short Form 36, and neurological exam) and a radiological (height of the adjacent disks, ostheophytis,…) follow-up.

The analysis of the current literature and statistical process leads to a total amount of 220 patients enrolled in the study. This is a multicentric study organized for a total duration of five years (two years for inclusions and three years of follow-up).