Department of Orthopaedic Surgery, Yong Loo Lin School of Medicine, National University of Singapore.
Spine (Phila Pa 1976). 2011 Oct 1;36(21):1752-9. doi: 10.1097/BRS.0b013e31822576a4.
A large animal study comparing interbody fusion of a bioresorbable scaffold loaded with either low-dose recombinant human bone morphogenetic protein 2 (rhBMP-2) or bone marrow-derived multipotent stromal cells (BMSCs).
To compare the quality of fusion resulting from implantation of medical grade poly (ε-caprolactone)-20% tricalcium phosphate (mPCL/TCP) scaffolds and two different bone growth stimulating agents.
Nondegradable cages have been used for interbody fusion with good results. However, the overall advantage of lifelong implantation of a nondegradable device remains a subject of ongoing debate. The use of bioresorbable scaffolds might offer superior alternatives. In this study, we evaluated the quality of fusion obtained with two potential bone graft substitutes.
Eleven Yorkshire pigs underwent a bisegmental (L2/L3; L4/L5) anterior lumbar interbody fusion (ALIF) in four groups, namely: (1) mPCL/TCP + 0.6 mg rhBMP-2; (2) mPCL/TCP + BMSCs; (3) mPCL/TCP (negative control); and (4) autologous bone grafts (positive control). RESULTS. The mean radiographic scores at 9 months were 3.0, 1.7, 1.0, and 1.8 for groups 1 to 4, respectively. The bone volume fraction of group 1 was two-folds higher than group 2. Histology, micro-computed tomographic scanning and biomechanical evaluation demonstrated solid and comparable fusion between groups 1 and 4. However, group 2 showed inferior quality of fusion when compared with groups 1 and 4 while group 3 showed no fusion even at 9 months. In addition, there was no evidence of implant rejection, chronic inflammation or any other complications.
mPCL/TCP scaffolds loaded with low-dose rhBMP-2 is comparable to autograft bone as a bone graft substitute in this large animal ALIF model. Although BMSCs lagged behind autograft bone and rhBMP-2, evidence of bone ingrowth in this group warrants further investigation. Our results suggest that mPCL/TCP scaffolds loaded with rhBMP-2 or BMSCs may be a viable alternative to conventional cages and autograft bone.
一项大型动物研究比较了椎间融合术，使用生物可吸收支架植入，支架分别负载低剂量重组人骨形态发生蛋白 2（rhBMP-2）或骨髓来源的多能基质细胞（BMSCs）。
比较使用医用级聚（ε-己内酯）-20%磷酸三钙（mPCL/TCP）支架和两种不同骨生长刺激剂植入后的融合质量。
不可降解的笼已被用于椎间融合，效果良好。然而，终生植入不可降解装置的整体优势仍是一个持续争论的话题。生物可吸收支架的使用可能提供更好的替代方案。在这项研究中，我们评估了两种潜在骨移植物替代物获得的融合质量。
11 头约克夏猪接受了四个组的双侧（L2/L3；L4/L5）前路腰椎椎间融合术（ALIF），具体分组如下：（1）mPCL/TCP+0.6mg rhBMP-2；（2）mPCL/TCP+BMSCs；（3）mPCL/TCP（阴性对照）；（4）自体骨移植物（阳性对照）。结果：9 个月时，各组的平均放射评分分别为 3.0、1.7、1.0 和 1.8。第 1 组的骨体积分数是第 2 组的两倍。组织学、微计算机断层扫描和生物力学评估显示，第 1 组和第 4 组之间的融合牢固且相当。然而，与第 1 组和第 4 组相比，第 2 组的融合质量较差，而第 3 组即使在 9 个月时也没有融合。此外，没有发现植入物排斥、慢性炎症或任何其他并发症。
mPCL/TCP 支架负载低剂量 rhBMP-2 与自体骨作为骨移植物替代物在这种大型动物 ALIF 模型中是相当的。虽然 BMSCs 落后于自体骨和 rhBMP-2，但该组有证据表明骨长入，需要进一步研究。我们的结果表明，负载 rhBMP-2 或 BMSCs 的 mPCL/TCP 支架可能是传统笼和自体骨的可行替代方案。
