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目的：比较坚硬接骨板和应力松弛接骨板固定后板下皮质骨内微循环的变化。方法：２８只家兔的两侧胫骨分别以不锈钢接骨板（坚硬接骨板）和螺孔内衬有粘弹性垫圈的不锈钢接骨板（应力松弛接骨板）做固定，并定期进行微血管造影，术后处死取材观察。结果：两种接骨板置入后均造成板下皮质骨缺血，２～４周后来自髓腔侧的血管扩张并侵入缺血区，８～１２周缺血区基本消失，皮质骨内血管继续增生呈网状，两组间比较，差异无显著性意义。１６周后应力松弛接骨板侧微血管容量不再改变，而坚硬接骨板侧血管继续扩张，形成较多血窦，血管容量进一步增加，并与应力松弛接骨板侧出现统计学差异。上述早期改变与血循环损伤有关，后期两种接骨板的差别则与其应力遮挡率不同有关。结论：应力松弛接骨板可有效地减缓和减轻坚硬接骨板造成的微血管形态改变及血管容量增加，从而避免严重的骨吸收和骨力学强度下降。
OBJECTIVE: To compare the changes of microcirculation in inferior cortical bone after fixation of hard plate and stress relaxation plate. Methods: Twenty-eight rabbits were fixed on both sides of the tibia with stainless steel plate (hard plate) and a stainless steel plate (stress relaxation plate) Death observed. Results: After the two kinds of bone plates were implanted, the cortical bone under the plate was caused to ischemia. After 2 to 4 weeks, the blood vessels from the medullary cavity side dilated and invaded into the ischemic area. The ischemic area disappeared after 8 to 12 weeks. Continue to proliferate reticular, between the two groups, the difference was not significant. After 16 weeks, the volume of capillaries on the plate of the stress relaxation did not change any more, while the rigid platelet side vessels continued to expand to form more sinusoids. The vascular capacity was further increased and there was statistical difference with the stress relaxation plate side. The early changes and blood circulation damage related to the late two difference between the bone plate and its stress shielding rate is different. CONCLUSIONS: Stress relaxation plate can effectively reduce and alleviate microvascular morphological changes and increase of vessel volume caused by rigid plate, so as to avoid serious bone resorption and decrease of bone mechanical strength.