Posterior spinal fusion of the cervical spine using the Alligator plate: operative technique and clinical results.

We have designed a new type of clamping plate called the "Alligator plate" for posterior cervical spinal fixation and used it in some cases with cervical instability. Seventeen patients with cervical instability treated by posterior cervical fixation using Alligator plate were clinically evaluated. As a control group, 21 patients treated by a wire fixation method (cerclage) were also evaluated. Clinical results were evaluated radiographically on dynamic flexion-extension lateral radiographs with confirmation of the fusion mass on oblique-view radiographs. The results of Alligator plate fixation were excellent in 15 patients, good in one and poor in one. The results of wire fixation were excellent in 15 patients, good in three, fair in one and poor in two. A safe and simple alternative instrumentation, the Alligator plate has sufficient stability to be useful for treating instability of the lower cervical spine.