Biologic enhancement of spinal fusion.

STUDY DESIGN

Literature review.

OBJECTIVES

To review the available animal and clinical data on biologic enhancements of spinal fusion.

SUMMARY OF BACKGROUND DATA

Lumbar spinal arthrodesis may result in pseudarthrosis in 5% to 35% of patients. Although much research has focused on the mechanical factors affecting spinal fusion, the use of internal fixation has not eliminated the problem of spinal nonunions. Accordingly, biologic enhancement of spinal fusion has become an important focus of spinal research.

METHODS

Medline and hand searches.

RESULTS

Electric stimulation, bone graft substitutes, and bone growth factors have been researched most extensively. Electric stimulation and early attempts at bone graft substitutes (allograft, xenograft) have yielded variable results. The feasibility of biologic enhancement of spinal fusion with osteoinductive growth factors has been shown in animals.

CONCLUSION

The efficacy of bone growth factors for lumbar fusion remains to be definitively established in humans.