The treatment of primary vertebral tumors by radical resection and prosthetic vertebral replacement.

The basic principles for the treatment of primary vertebral tumors include radical resection of the tumor, insertion of a prosthetic vertebral body, and bone grafting within and around the prosthetic vertebral body. Since 1970, the authors have treated 12 cases with this procedure. In order to improve the vertebral prosthesis, 94 dried adult vertebral column specimens were studied. The anterior cortex of each vertebral body was thicker than the posterior cortex. The thickness of the anterior cortex of the dorsolumbar vertebral bodies progressively increases from the proximal to caudal vertebra. The lower lumbar vertebrae are therefore almost twice as thick as the upper dorsal vertebrae. The cortices of the vertebral bodies, especially the anterior cortex, serve as a strut against the pressure of the prosthesis. Four types of prostheses were used. The Type 1 prosthesis failed to take into account the anatomic features of the dorsolumbar vertebral bodies in cross section. Types 2, 3, and 4 are modified versions with specific indications for their use.