Journal de la colonne vertébrale

A Radiographic Analysis of Posterolateral Lumbar Fusion Utilizing an Allogeneic Growth Factor Compared to Recombinant Human Bone Morphogenetic Protein-2 (rhbmp-2)

Abstract

Howard AN, Christopher Yeung, Justin Field and Jeffrey Roh

Posterolateral lumbar fusions have been successfully used to surgically treat mechanical back pain, low grade spondylolisthesis and other degenerative spinal conditions. The addition of biological grafts to augment available autologous bone has further improved fusion rates, yet, some of these biologics have been found to cause deleterious post-operative clinical situations and sometimes are used in an off-label manner. A biological alternative that provides equivalent fusion rates with a similar, or lower, risk profile is desirable. In this study, we report on fusion rates associated with the use of an allogeneic growth factor (OsteoAMP) to assist with lumbar spinal arthrodesis with and without augmentation with bone marrow aspirate as compared to rhBMP-2 used with and without the allogeneic growth factor. Patients having posterolateral lumbar fusion were evaluated for fusions at clinically relevant time points. A total of 302 patients (146 growth factor with BMA, 81 growth factor without BMA, 50 rhBMP-2 alone, 25 rhBMP-2 with allogeneic growth factor) were retrospectively reviewed. The growth factor with BMA group had approximately an 88% fusion rate by 12 months and 99% by 24 months. The growth factor non- BMA group had a fusion rate of 35% by 12 months and exceeding 98% at the 2 year follow up. The OsteoAMP augmented rhBMP-2 group had fusion rates of 33% at 12 months and 100% at 24 months, while the rhBMP-2 alone group only attained a 14% fusion rate at 12 months and a 32% fusion rate at 24 months. The allogeneic growth factor appears to provide a viable option to assist with the development of posterolateral spinal arthrodesis. Longer follow up and increased patient sample size is needed to further confirm these initial results.