Union Rates of Local Autobone and beta-Tricalcium Phosphate Mixed Graft in Lumbar Posterolateral Fusion

ABSTRACT

STUDY DESIGN: A retroprospective study. OBJECTIVES: We used a local autobone and beta-tricalcium phosphate mixed graft with posterolateral fusion in spinal stenosis and spondylolisthesis and evaluated union rates to verify the efficacy. SUMMARY OF LITERATURE REVIEW Several reports have shown high union rates of posterolateral fusion using beta-tricalcium phosphate. However, in Korea, only one study reported a low union rate. MATERIALS AND METHODS: Forty-two patients who underwent lumbar posterolateral fusion with a local autobone and beta-tricalcium phosphate mixed graft from September 2010 to July 2011 were followed up. There were 32 cases with spinal stenosis and 10 cases with spondylolisthesis. Bone fusion was determined along with the fusion rates based on Lenke's criteria. Clinical outcomes were determined using Kim's method. RESULTS: In spinal stenosis, bone union was presented in 19 cases(59.4%) out of 32 cases and in spondylolisthesis, bone union was presented in 7 (70.0%) out of 10. In spinal stenosis, 12 cases showed excellent outcome, 16 good, 3 fair and 1 poor, 27 cases(87.5%) were superior to the good. In spondylolisthesis, 2 cases showed excellent outcome, 5 good, 3 fair and 0 poor, 8 cases(70.0%) were superior to the good. CONCLUSIONS: Posterolateral fusion using a local autobone and beta-tricalcium phosphate mixed graft showed lower bone fusion rates. We need further studies to enhance the fusion rate when using local autobone and beta-tricalcium phosphate mixed grafts.