Efficacy of Interspinous Process Fusion with Recombinant Human Bone Morphogenetic Protein-2 Delivered by a Synthetic Polymer and β-Tricalcium Phosphate

常规的脊柱椎间融合术和后外侧融合术涉及使用大切口、分离和部分横断椎旁肌肉以暴露脊柱后部。另一方面，进行棘突间融合的方法仅涉及肌肉剥离，并保留了脊柱的几乎所有结构成分。如果使用骨形态发生蛋白（BMP）成功实现棘突间融合，则可以减少脊柱上的轴向压缩载荷。这种方法将是治疗腰椎疾病的一种不太病态的手术选择。在这项研究中，我们试图通过使用重组人（rh）BMP-2的递送系统来实现棘突间融合并评估其在实验兔模型中的功效。我们通过在8周内植入由60μg rhBMP-2组成的可生物降解的骨诱导植入物，在实验性兔模型中实现了坚固的棘突间融合。棘突间融合的有效性通过脊柱的稳定性和轴向压缩载荷引起的椎间盘内压力的降低来表示。

Regular spinal interbody fusion and posterolateral fusion involve the use of large incisions, dissection, and partial transection of the paravertebral muscle to expose the posterior spine. On the other hand, the approach to perform an interspinous process fusion involves only muscular stripping and preserves almost all structural components of the spine. If interspinous process fusion by use of Bone morphogenetic proteins (BMPs) is successfully achieved, it could reduce the axial compressive load on the vertebral column. This method would be one of the less morbid surgical options for treatment of lumbar disorders. In this study, we attempted to achieve an interspinous process fusion and evaluate its efficacy in experimental rabbit models by using a delivery system for recombinant human (rh) BMP-2. We achieved solid interspinous process fusion in experimental rabbit models by implanting a biodegradable bone-inducing implant composed of 60μg of rhBMP-2 within a period of 8 weeks. The efficacy of the interspinous process fusion was indicated by the stabilization of the spinal column and decrease in the intradiscal pressure due to axial compressive loading.