周期性载荷对骨缺损修复中微血管重建的影响

EFFECT OF CYCLIC LOADS ON REVASCULARIZATION IN HEALING OF BONE DEFECT

为了观察周期性载荷对骨缺损修复过程中微血管重建的影响，采用２０只家兔，双侧胫骨中部用骨钻制作骨缺损模型。左侧施加周期性载荷为实验组，右侧不施加载荷为对照组。分别于骨折第５，１０，２０及３０天处死动物，作组织学检查。结果表明，实验组血管重建过程较对照组提前７天左右。认为，骨折第５天周期性载荷对骨缺损的修复无作用。

In order to study the biomechanical effect of cyclic loads on revascularization in bone healing, 20 rabbits were chosen for following experiments. Two 2 mm in diameter holes were made at the middle segment of both right and left tibia. A 2 mm in diameter nail was put in 15 mm proximal to the upper hole, and another was put in 15 mm distal to the lower hole. The wound was covered by direct suture with the ends of the nails kept 15 mm out of skin. The medial ends of the two nails were fixed by an iron plate, while the lateral ends were left for cyclic loads. Three Hz cyclic loads, which was near to the cyclic forces when a rabbit runs, was added to the left tibia for experiment, and no loads was add to the right tibia for control. A group of five rabbits were sacrificed respectively in 5, 10, 20 and 30 days postoperatively. The solution of 2% India ink and gelatin was irrigated from aorta to the bone defects. Then the tibia was removed for histologic study. The changes of cells and microvessel were observed. It was shown that the revascularization in experiment group was about 7 days earlier than that of control. The effect was at its peak from 10 to 30 days. It was concluded that cyclic loads could promot revascularization in the healing process of bone defect.