Repair of segmental bone defects in the rat: An experimental model of human fracture healing
Repair of segmental bone defects in the rat: An experimental model of human fracture healing
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DOI：
10.1016/s8756-3282(99)00167-2
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发表时间：
1999-09-01
期刊：
影响因子：
4.1
通讯作者：
McGuire, MH
中科院分区：
文献类型：
--
作者：
Chakkalakal, DA;Strates, BS;McGuire, MH
动物中的骨修复模型可以被认为与人类骨折愈合相关，因为模型中修复过程中的事件顺序反映了人类骨折愈合顺序。在本研究中，最近开发的节段性缺损模型在大鼠腓骨人类骨折愈合的相关性进行了研究，通过评估腓骨刚度的时间进展，修复部位的矿物质含量和组织学变化。在该模型中，通过将手术创建的2 mm长的缺损与5 mm长的脱矿骨基质（DBM）管状样本移植，将其插入腓骨的切割端。愈合腓骨刚度的暂时增加表现出与人类骨折愈合中测量的生物力学愈合曲线相似的模式。这种模式的特点是在术后4-7周内出现一个短暂的刚度迅速上升的阶段，与修复组织中矿物质含量的急剧增加有关。在此之前是一个几乎为零的刚性阶段，随后是一个缓慢增长的阶段，接近平台。在组织学上，在前2周内，成软骨细胞和成骨细胞胚基从骨膜外和骨膜下（靠近腓骨移植物连接处）区域浸润DBM移植物。DBM移植物承担了“桥接愈伤组织”的作用。“到第6-8周，大部分DBM转化为新的编织骨和小梁骨，具有最大的成骨活性和最小的软骨内骨化。3周时，髓骨痂形成开始于邻近缺损皮质和骨内膜表面的直接新骨形成，以及缺损中心的未分化细胞。DBM移植物的存在改变了啮齿类动物中常见的骨修复过程，以重现人类骨折愈合的连续阶段，包括骨髓骨痂的形成、与编织骨和板层骨的结合以及髓管的重建。(C)1999年，Elsevier Science Inc. All rights reserved.
Bone repair models in animals may be considered relevant to human fracture healing to the extent that the sequence of events in the repair process in the model reflect the human fracture healing sequence. In the present study, the relevance of a recently developed segmental defect model in rat fibula to human fracture healing was investigated by evaluating temporal progression of rigidity of the fibula, mineral content of the repair site, and histological changes. In this model, a surgically created 2-mm-long defect was grafted with a 5-mm-long tubular specimen of demineralized bone matrix (DBM) by inserting it over the cut ends of the fibula. The temporal increase in rigidity of the healing fibula demonstrated a pattern similar to biomechanical healing curves measured in human fracture healing. This pattern was characterized by a short phase of rapidly rising rigidity during weeks 4-7 after surgery, associated with a sharp increase in the mineral content of the repair tissue. This was preceded by a phase of nearly zero rigidity and followed by a phase of slow rate of increase approaching a plateau. Histologically, chondroblastic and osteoblastic blastema originating from extraskeletal and subperiosteal (near fibula-graft junction) regions, infiltrated the DBM graft during the first 2 weeks. The DBM graft assumed the role of a "bridging callus." By weeks 6-8, most of the DBM was converted to new woven and trabecular bone with maximal osteoblastic activity and minimal endochondral ossification. Medullary callus formation started with direct new bone formation adjacent to the cortical and endosteal surfaces in the defect and undifferentiated cells in the center of the defect at 3 weeks. The usual bone repair process in rodents was altered by the presence of the DBM graft to recapitulate the sequential stages of human fracture healing, including the formation of a medullary callus, union with woven and lamellar bone, and recreation of the medullary canal. (C) 1999 by Elsevier Science Inc. All rights reserved.