The effect of bone graft extenders to enhance the performance of iliac crest bone grafts in instrumented lumbar spine fusion.

Overview

Allograft bone extenders are commonly used in spinal surgery to increase the available graft volume, thereby promoting and achieving a solid fusion mass. We report a single surgeon's use and early results of autologous bone graft and allograft demineralized bone matrix in 65 patients undergoing lumbar spinal fusion. Of the patients included in this study, 59 (91%) patients underwent surgical intervention for lumbar spinal stenosis, three (5%) patients had lumbar spondylolisthesis, two (3%) patients had stenosis, and one (1%) patient had bilateral spondylolysis. Forty-three (64%) women and 22 (36%) men were included in the study. The average patient age was 56 years (20-85 years, SD= +/- 16). Independent radiographic evaluation was performed. Each subsequent radiographic follow-up revealed increased improvement in average Lenke score and was statistically significant between the early (1 month) and recent (12 month) follow-ups. There were statistically significant changes in Lenke score between 1 month and 3 months follow-up (P<.01), between 3 months and 6 months follow-up (P<.001), and between 6 months and 12 months follow-up (P<.01). The gradual and constant increment of improvement in radiographic measurements in this preliminary series may indicate a positive effect of the use of bone graft extenders that may decrease the required amount of autologous bone graft. Bone graft extenders also may minimize the risks and complications associated with the harvesting procedure.