Markel M D, Wikenheiser M A, Chao E Y
Department of Orthopedics, Mayo Clinic, Rochester, Minnesota.
J Bone Joint Surg Am. 1991 Jul;73(6):914-23.
The histomorphometric, material, and structural properties of the reparative tissue and bone that formed in a two-millimeter tibial defect in dogs were determined at two, four, eight, and twelve weeks after the operation. At two weeks, the tibial defect was filled mainly with undifferentiated connective tissue. After two weeks, the relative proportion of undifferentiated connective tissue decreased and the amount of bone progressively increased throughout the twelve weeks. New bone formed primarily by intramembranous ossification, with a small degree of endochondral ossification. At twelve weeks, bone occupied 62 per cent of the defect. The calcium content of the reparative tissue increased between four and eight weeks and then, at twelve weeks, reached a plateau of 77 per cent that of normal cortical bone. Anisotropy of the new bone that formed in the defect increased from 13.8 per cent to 26 per cent, and the mean width of the trabecular bone increased 27 per cent between the eighth and twelfth weeks. Maximum torque and torsional stiffness increased between two and eight weeks and then, by twelve weeks, the values leveled off at 44 and 29 per cent of the values for intact bone. Indentation stiffness increased between the fourth and twelfth weeks; at twelve weeks, it was 22 per cent of the stiffness of normal cortical bone. Indentation stiffness increased 283 per cent between eight and twelve weeks, despite insignificant changes in calcium content, amount of new bone, non-osseous space, water content, or volume of trabecular bone during this time. This change in indentation stiffness did correlate with increases in anisotropy of the new bone between eight and twelve weeks.
在犬类两毫米胫骨缺损处形成的修复组织和骨的组织形态计量学、材料及结构特性，于术后两周、四周、八周和十二周进行测定。术后两周时，胫骨缺损处主要填充着未分化的结缔组织。两周后，未分化结缔组织的相对比例降低，在整个十二周期间骨量逐渐增加。新骨主要通过膜内成骨形成，伴有少量软骨内成骨。在十二周时，骨占据缺损的62%。修复组织的钙含量在四周至八周之间增加，然后在十二周时达到正常皮质骨钙含量的77%的平台期。缺损处形成的新骨的各向异性从13.8%增加到26%，小梁骨的平均宽度在第八周和第十二周之间增加了27%。最大扭矩和扭转刚度在两周至八周之间增加，然后到十二周时，这些值稳定在完整骨相应值的44%和29%。压痕硬度在第四周和第十二周之间增加；在十二周时，它是正常皮质骨硬度的22%。尽管在此期间钙含量、新骨量、非骨空间、含水量或小梁骨体积没有显著变化，但压痕硬度在八周和十二周之间增加了283%。这种压痕硬度的变化确实与八周和十二周之间新骨各向异性的增加相关。
