Alternative tricortical methods of screw implantation for anterior cervical plate fixation: a preliminary report.

An experience with 26 cases of anterior cervical interbody plate fixation with an alternative method of screw implantation is described. The follow up ranges from 15 to 51 months. The screws are placed obliquely such that they engage the anterior cortex of the body and traverse through the cortices adjoining the disc space. By this method the screws not only hold the plate firmly with a tricortical purchase, but also, by virtue of their course, stabilise the two adjoining vertebral bodies by themselves. In five of these cases only tricortical screws without the metal plate were used for fixation. Cortico-cancellous iliac crest bone graft shredded into small pieces is placed between the vertebral bodies after adequately preparing the bed. A 100% bony union rate was achieved, with no morbidity or instrument fatigue or failure. The described technique of plate fixation appears to be biomechanically stronger. It provided a rigid segmental internal fixation permitting early mobilisation of the patient with minimal external support.