Johnson K D, August A, Sciadini M F, Smith C
Department of Orthopaedics and Rehabilitation, Vanderbilt University School of Medicine, Nashville 37232-2550, USA.
J Orthop Trauma. 1996;10(1):28-36. doi: 10.1097/00005131-199601000-00005.
The recent orthopaedic literature reflects a growing number of bone graft substitutes and osteogenic growth factors under investigation in a number of animal models. We attempted to establish a well-controlled, large animal model of a segmental defect in a weight-bearing long bone by developing a bilateral diaphyseal radial defect model in the canine. We also evaluated the effectiveness of ground cortical autograft as a graft material. Twenty-three adult mongrel dogs underwent bilateral radial osteotomies with creation of a 2.0-2.5-cm diaphyseal defect on each side. All dogs received cancellous autograft (CAN) on one side, nine received no graft material (DEF) on the opposite side, and 14 received morselized cortical autograft (CORT) on the opposite side. Radii were stabilized by external fixation. Animals were followed radiographically at 6-week intervals to evaluate the healing process. Thirteen dogs were sacrificed at short-term follow-up (8-12 weeks postsurgery) and 10 at long-term (16-24 weeks). Biomechanical torsion testing to failure and histological evaluation were performed on each defect. All CAN radii achieved union (100%) while only one of nine DEF radii (11%) and none of 14 (0%) of CORT radii achieved union. Statistically significant differences in biomechanical parameters between both test groups and their corresponding autograft control radii were found. Histology revealed fibrous nonunions in the DEF and CORT radii. These results demonstrate that the bilateral canine radial defect model represents a consistent and reproducible model for bone healing of segmental defects in weight-bearing long bones and that ground cortical autograft is an ineffective graft material.
近期的骨科文献表明，在众多动物模型中，正有越来越多的骨移植替代物和成骨生长因子处于研究阶段。我们试图通过构建犬双侧骨干桡骨缺损模型，建立一个对照良好的负重长骨节段性缺损的大型动物模型。我们还评估了磨碎的皮质自体骨作为移植材料的有效性。23只成年杂种犬接受了双侧桡骨截骨术，每侧制造一个2.0 - 2.5厘米的骨干缺损。所有犬一侧接受松质骨自体骨（CAN）移植，另一侧9只不接受移植材料（DEF），14只接受磨碎的皮质自体骨（CORT）移植。桡骨通过外固定进行固定。每隔6周对动物进行放射学检查以评估愈合过程。13只犬在短期随访（术后8 - 12周）时被处死，10只在长期（16 - 24周）时被处死。对每个缺损进行生物力学扭转试验直至失效并进行组织学评估。所有接受CAN移植的桡骨均实现愈合（100%），而9只DEF组桡骨中只有1只（11%）实现愈合，14只CORT组桡骨无一（0%）实现愈合。在两个试验组与其相应的自体骨对照桡骨之间，生物力学参数存在统计学上的显著差异。组织学显示DEF组和CORT组桡骨为纤维性骨不连。这些结果表明，双侧犬桡骨缺损模型是负重长骨节段性缺损骨愈合的一个一致且可重复的模型，并且磨碎的皮质自体骨是一种无效的移植材料。
