Hidden Dangers of Titanium Cages Used in Neck Fusion
Spinal fusion is usually done with bone graft material. The bone can be taken from the patient's own hip or using bone donated by someone else. There are problems with bone grafts, so doctors are looking for ways to replace them. Various bone substitutes are being used. So are titanium cages. The authors of this study report the hidden dangers in using cage implants to fuse the cervical spine (neck).
When cages are used, the mesh implant is inserted between the vertebral bones. The cage can also replace the main body of a vertebra when part or all of it is removed. Cages help support the bones and keep the height of the spine the same. This is important in reducing pressure on spinal nerve roots and keeping the ligaments at the right tension.
Only a few studies have been done to look at the problems that come with cervical fusion using titanium cages. The authors of this report want to add to what we know about this method of treating a problem neck. In this study, cervical fusion was done from the front of the spine in 24 patients. This approach is called anterior fusion. The disc was removed in all the patients. Some or all of the front part of the vertebra was removed. The removed bone was ground up and placed inside the cages. The cages were put in place. A metal plate was attached to the front of the spine where the bone had been cut out.
The results were measured using patient reports of symptoms and X-rays. X-rays show the alignment of the cage, graft, and bones. The status of the fusion is also seen on X-rays. Any problems with the implants were also recorded. These included any movement, loosening, or breakage of the cage, plate, or screws.
The fusion rate was 96 percent, but it took an average of six months for a solid fusion to occur. Overall, symptoms were much improved after surgery. The authors conclude that titanium mesh cages work well for anterior cervical fusion. With the bone taken from the front of the vertebra, there's no need to harvest bone from the hip. However, the cages tend to shift and sink and must be watched carefully.
Masahiro Kanayama, et al. Pitfalls of Anterior Cervical Fusion using Titanium Mesh and Local Autograft. In Journal of Spinal Disorders. December 2003. Vol. 16. No. 6. Pp. 513-518.