Changes in canine cortical and cancellous bone mechanical properties following immobilization and remobilization with exercise
Changes in canine cortical and cancellous bone mechanical properties following immobilization and remobilization with exercise
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DOI：
10.1016/s8756-3282(97)00167-1
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发表时间：
1997-11-01
期刊：
影响因子：
4.1
通讯作者：
Lane, NE
中科院分区：
文献类型：
--
作者：
Kaneps, AJ;Stover, SM;Lane, NE
本研究的目的是评估皮质骨和松质骨对单侧肢体制动的反应，随后，在年轻成年犬模型中进行运动再动员。将14只1-2岁杂种犬的右前肢用绷带固定于非负重位16周。6只对照犬未接受治疗。16周时，对7只固定犬和3只对照犬实施安乐死。其余7只固定的狗开始恢复方案，包括16周的犬舍禁闭（右前肢没有包扎），然后是16周的跑步机运动，每周进行三次。在48周时对这7只犬和3只对照雌兔实施安乐死。用双能X线骨密度仪测定桡骨近端骨密度，用计算机断层扫描测定肱骨中段横截面积。对肱骨进行了头尾向三点弯曲至失效的测试。测定肱骨外髁松质骨芯的湿表观密度，并测试压缩失效。采用Kruskal-Wallis检验和事后检验，比较固定（右前肢）、对侧负重（左前肢）和对照前肢之间的机械性能、骨密度和横截面积。在16周时，固定肢体的骨密度、皮质骨负荷、屈服强度和刚度以及松质骨失效应力、屈服应力和模量均显著低于对照肢体（p < 0.02）。固定后肢体松质骨力学性能为对照值的28%~ 74%，皮质骨力学性能为对照值的71%~ 98%。再动员32周后，皮质骨和松质骨的力学性能与对照值没有差异，但皮质骨的破坏应力和模量在再动员肢体和对照肢体之间显著较高（p < 0.01）。总之，16周的前肢制动与显著较低的机械性能相关，松质骨的性能比皮质骨的性能差异更大。32周的恢复（包括16周的跑步机运动）后，机械性能与对照值没有差异。(C)Elsevier Science Inc.出版。All rights reserved.
The purpose of this study was to assess cortical and cancellous bone responses to unilateral limb immobilization and, subsequently, to remobilization with exercise, in a young adult canine model. Right forelimbs of 14 1-2-year old mongrel dogs were immobilized in a non-weight-bearing position by a bandage for 16 weeks. Six control dogs were untreated. At 16 weeks, seven immobilized and three control dogs were euthanized. The remaining seven immobilized dogs began a recovery protocol consisting of 16 weeks of kennel confinement (without the right forelimb bandaged) followed by 16 weeks of treadmill exercise conducted three times per week. These seven dogs and three control does were euthanized at 48 weeks. Bone mineral density of the proximal radii was determined with dual-energy X-ray absorptiometry and humeral middiaphyseal cross-sectional areas were determined with computed tomography. Humeri were tested in craniocaudal three-point bending to failure. Cancellous bone cores from the lateral humeral condyles had wet apparent density determined and were tested to failure in compression. Mechanical properties, bone density, and cross-sectional areas were compared between immobilized (right forelimb), contralateral weight bearing (left forelimb), and control forelimbs with Kruskal-Wallis and post hoc tests. At 16 weeks, bone mineral density, cortical load, yield, and stiffness as well as cancellous bone failure stress, yield stress, and modulus were significantly lower (p < 0.02) for immobilized limbs than control limbs. Immobilized limb cancellous bone mechanical properties were 28%-74% of control values, and cortical bone mechanical properties were 71%-98% of control values. After 32 weeks of remobilization, cortical and cancellous bone mechanical properties were not different from control values except that cortical bone failure stress and modulus were significantly higher (p < 0.01) between remobilized and control limbs. In summary, 16 weeks of forelimb immobilization was associated with significantly lower mechanical properties, and with greater differences in cancellous than cortical bone properties. Mechanical properties were not different from control values after 32 weeks of recovery that included 16 weeks of treadmill exercise. (C) 1997 by Elsevier Science Inc. All rights reserved.