The fate of anterior vertebral bone grafts in patients irradiated for neoplasm

Abstract

Perioperative irradiation is often used with anterior decompression and vertebral interbody fusion for the treatment of spinal neoplasms, yet little is known regarding the healing potential of these grafts. This review of 25 patients with neoplasm who had anterior vertebrectomy, bone strut insertion, and perioperative irradiation was performed to look specifically for evidence of radiographic fusion as determined by plain radiographs, tomograms, or computed tomography reconstruction. Four of 25 patients (16%) were judged to have a pseudarthrosis. All four pseudarthrosis patients but only four of 21 fusion patients had 4000 cg or more of irradiation, a statistically significant difference. There was a trend for lumbar lesions to have a higher risk for nonunion. Concomitant posterior stabilization did not necessarily prevent pseudarthrosis. Two iliac strut grafts with a pseudoarthrosis developed late fracture and one went on to collapse into kyphosis. The pseudarthrosis rate of anterior vertebral strut grafts in the face of irradiation for tumor is relatively high, and late graft fracture can occur if pseudarthrosis develops. Probable risk factors include irradiation greater than 4000 cg and lumbar lesions. Posterior stabilization to protect the graft may be warranted in the highest-risk patients.