Research Of Drawing Out The Screws Intermittently To Prevent The Femoral Head Necrosis

Objective: To study the effect of drawing out the screws intermittently on thehealing of femoral neck fracture. Methods: twenty healthy rabbits with matured s-keleton were used to make the model of femoral neck fracture fixed with three c-ompression Kirschner wires. One side were selected randomly to be the experimen-ttal side and the three wires were drawn out respectively at4th,6th,8th week af-ter the operation. The other side was the central side and the three wires were di-vided into A, B, C groups, which were sacrificed when it was6、8、10th week a-fter theoperation. We compared the experimental side with the control side on X r-ay, SPECT, and microscopic inspection. Results: The data of SPECT appears：theblood flow in the artery and the vein of the experimental side is better than thecontrol side in group A, B. There is no difference between the two sides in groupC. Themicroscopic inspection shows: The generation of new blood capillary and in-terlacedbone in the experiment side were more rapid than the controI side. The cl-earance of necrosis bone chips in the experiment sidewere accelerated. Conclusion:Drawing out wire intermittently can improve the blood flow of the femoral headand reduce the ratio of femoral head necrosis．...