Finite element analysis of the multiple drilling technique for early osteonecrosis of the femoral head

Abstract

Objective To explore the influencing factors in traditional single large channel core decompression and multiple drilling technique in the treatment of early osteonecrosis of the femoral head with the methods of finite element analysis. Methods The right femur of healthy adults were choosen as the research object, and CT scanning was conducted to get the images of cross sections.The images were then inputted into computer to get contour of femur and rebuild 3D model.Distal end of femur was completely fixed, and 570N pressure on the femoral head was applied according to the three-dimensional space distribution of femur force under physiological state. Three-dimensional finite element models were founded with the necrotic range of 15% and 30%, then the stress distributions of cancellous bone and cortical bone of femoral head were obtained through the models. Results Different methods of decompression and different numbers of channel cores would lead to a different stress value: stress concentration would appear on femoral head after core decompression. Multiple drilling technique would get a more stress concentration comparing to traditional single large channel core decompression, the stress value was summit of cortical bone and cancellous bone would both less than their yield strength and tensile strength of femoral hard. Conclusions Multiple drilling technique is more effective and feasible in the treatment of early osteonecrosis of the femoral head comparing to traditional single large channel core decompression. Key words: Core decompression; Multiple channels; Osteonecrosis of the femoral head; Finite element method