Anterior cervical interbody fusion with threaded cylindrical bone.

The author describes some modifications of the original Cloward method of cervical intervertebral body fusion. These modifications include the intraoperative threading of the standard cylindrical graft dowel (either autologous or heterologous) and the development of two new instruments designed to insert the graft into the intervertebral space. This modified technique was tested in an experimental study using the cervical spine of cadavers, after which a series of 37 patients were operated on with this method. The results of both series are presented. The chief advantages of this type of interbody fusion over the standard technique are: 1) easier insertion of the graft into the intervertebral space; and 2) decrease in complications. Complications with cervical interbody fusion, both minor (such as partial displacement of the graft, vertebral angulation, and radicular injury) and major (such as spinal cord compression and/or contusion), are fortunately infrequent, but they are important because of their irreparable consequences.