Biomechanical study of cervical spine stabilization with methylmethacrylate.

Polymethylmethacrylate (PMMA) has been used to provide immediate fixation in the spine, especially in the cervical region. With its use spreading to nontumor cases and a younger patient population, its biomechanical contribution to the stability and strength of the injured spine becomes increasingly important. The present study is unique, as it provides, for the first time, results of a three-dimensional stability and flexion strength testing of a surgical specimen removed at autopsy after 7 years. Also tested, in the identical manner, is a normal specimen to provide control data. The PMMA specimen, as compared with the control, was generally found to have less motion. Its flexion strength was at par with that of the control, although it did not exhibit the initial low-stiffness region of the normal spine specimen.