以有限元,临床及实验研究论髌骨及其张力带内固定术

AN APPROACH TO PATELLA AND ITS INTERNAL FIXATION WITH THE TENSION BAND BY FINITE ELEMENT ANALYSIS: A CLINICAL AND EXPERIMENTAL STUDY

In this article a finite-element analysis model for the patella is constructed by a plane stress method. This study points out that in patella fracture, Kirschner's wire shoild be set at the fore 1/3 part in the patella tension zone, or in the center 1 / 2 part of the transition zone to establish the tension band hoop. The wire must adequately bind. Neither exessive tightening nor loosening can achieve optimum stress. Vanriant fixations are compared and "double bow "fixation is recommended as the most reasonable type. Two fresh, amputated specimens were studied. The study proves that most of the patella's surface stress is affected by the muscle force of the quadriceps femoris, and next caused by the bending degress of the knee joint. The elastic internal fixation of the tension band is sufficient for maintaining and for gentle bending or stretching when external fixation is removed after an operation. The results suggest that strenous motion of more than 90 degrees is not recommendable. 57 convalescents of 83 patients undergoing operations on the tension band were followed up for an average of 23 months in 1983-1987. There is a success rate of up to 91.23%.