A Prospective Trial Comparing L4/5 Instrumented Posterolateral Fusion for Degenerative Spondylolisthesis Performed with Local Bone Graft Alone versus Posterior Iliac Crest Graft and Local Bone Graft versus Beta Tricalcium Phosphate and Local Bone Graft

Abstract

Introduction Prospective randomized radiological comparative study on the status of fusion in single level instrumented posterolateral lumbar fusion in low-grade spondylolisthesis using local bone graft versus iliac crest bone graft and local bone versus β-tricalcium phosphate and local bone graft. Materials and Methods A total of 24 patients in three groups with degenerative low-grade spondylolisthesis with stenosis randomly underwent decompressive laminectomy and single level instrumented posterolateral fusion with either local bone only or iliac crest bone graft with local bone or β-tricalcium phosphate and local bone graft. Each group consisted of eight patients and was followed for a minimum of 2 years after which a CT scan was done to evaluate the fusion mass according to the Lenke et al classification system. Results At the end of 2 years, no pseudoarthrosis was observed in either of the three groups. In the local bone graft only group, four (50%) patients had a definite solid fusion mass while the remaining four (50%) had a probable solid fusion mass. In the iliac crest group, seven (87.5%) had a definite fusion mass while one patient had a probable fusion mass. In the β-tricalcium phosphate group, five (62.5%) patients had a definite fusion while three (37.5%) had a probable solid fusion mass. Although iliac crest graft remains as the gold standard, its associated donor site morbidity has limited its use. Hence, local bone graft or substitutes such as β-tricalcium phosphate are frequently used. However, there seems to be no significant advantage of β-tricalcium phosphate over iliac crest graft in terms of the fusion status. Conclusion Although iliac crest bone graft remains the gold standard in lumbar fusion procedures, its associated morbidity limit its usage. Hence, local bone alone or combined with β-tricalcium phosphate are frequently used. However, there is no significant advantage of β-tricalcium phosphate over the local bone graft or iliac crest graft in terms of the fusion status. Disclosure of Interest None declared References Sengupta DK, Truumees E, Patel CK, et al. Outcome of local bone versus autogenous iliac crest bone graft in the instrumented posterolateral fusion of the lumbar spine. Spine 2006;31(9):985–991 Herzog RJ, Marcotte PJ. Assessment of spinal fusion. Critical evaluation of imaging techniques. Spine 1996;21(9):1114–1118 Larsen JM, Rimoldi RL, Capen DA, Nelson RW, Nagelberg S, Thomas JC Jr. Assessment of pseudarthrosis in pedicle screw fusion: a prospective study comparing plain radiographs, flexion/extension radiographs, CT scanning, and bone scintigraphy with operative findings. J Spinal Disord 1996;9(2):117–120 Zdeblick TA. A prospective, randomized study of lumbar fusion. Preliminary results. Spine 1993;18(8):983–991 Lenke LG, Bridwell KH, Bullis D, Betz RR, Baldus C, Schoenecker PL. Results of in situ fusion for isthmic spondylolisthesis. J Spinal Disord 1992;5(4):433–442 Dimar JR II, Glassman SD, Burkus JK, Pryor PW, Hardacker JW, Carreon LY. Two-year fusion and clinical outcomes in 224 patients treated with a single-level instrumented posterolateral fusion with iliac crest bone graft. Spine J 2009;9(11):880–885 Dai LY, Jiang LS. Single-level instrumented posterolateral fusion of lumbar spine with beta-tricalcium phosphate versus autograft: a prospective, randomized study with 3-year follow-up. Spine 2008;33(12):1299–1304