Patient satisfaction and radiographic outcomes after lumbar spinal fusion without iliac crest bone graft or transverse process fusion

Iliac crest bone graft (ICBG) remains the gold standard for promoting bony fusion of the spine. However, harvest-site infection and pain are two of the most significant drawbacks of using iliac crest autograft in spinal fusion procedures. The rationale for its continued use, despite these drawbacks, has been based on the relatively higher rate of fusion reported in the literature. Therefore, the objective of this study was to determine whether modern allograft and fusion-promoting materials combined with local bone graft results in acceptable fusion rates and patient satisfaction. We retrospectively reviewed the clinical, surgical, and radiographic records of 200 consecutive patients with symptomatic degenerative diseases of the lumbar spine who underwent non-revision fusion using local bone graft combined with recombinant human bone morphogenetic protein (rhBMP)-2 with or without allograft. Rates of radiographic fusion and patient satisfaction were analyzed at discharge, 6 months, and 12 months, and every year thereafter. Mean follow-up was 32 months. Fusion was performed across an average of 2.5 levels and the overall fusion rate was 97%. In patients undergoing posterior fixation only there was a 5% incidence of pseudarthrosis, while the incidence was only 0.5% for patients undergoing circumferential fixation. Overall patient satisfaction at discharge was good to excellent in over 90% of patients and did not significantly change at the 6 month, 12 month and 24 month follow-up. In conclusion, there is no significant difference in rates of spinal fusion using laminectomy bone autograft combined with rhBMP-2 with or without allograft, compared to historical controls using ICBG. Fusion rates may be further improved with the use of circumferential fixation. Patient satisfaction remained high and might be because the morbidity associated with harvesting ICBG was avoided, as was the additional muscle dissection required for the fusion of lateral transverse processes.