Threaded cages for degenerative cervical disease.

Multiple techniques are used to accomplish anterior interbody fusion in the cervical spine. These various options reflect the lack of any one approach to obtain superior results. Extrapolating from the lumbar spine experience, a cervical cage was proposed as an alternative to the status quo. A device evaluation study was done to determine the safety and efficacy of the cage with a comparison with current allograft or autograft fusion techniques. The study resulted in two publications. One study is a multicenter trial whereas the other is a one-author study with long-term results. A review of the data from both studies follows. Comparable outcomes were seen with the allograft and autograft control group and the experimental group in the multicenter trial. However, that study reported significantly better fusion rates for the patients with cervical cages compared with the control group. Both studies reported a high percentage of donor site morbidity in the patients in the control group who had autograft fusion. A trend toward better outcomes for patients who received a cervical cage was seen in the long-term followup study. The data presented suggest interbody fusion cages are a safe and effective treatment of degenerative cervical disc disorders and avoid iliac crest donor site morbidity.