RESUMO
Bone resorption around femoral stem as an effect of stress shielding and a subsequent adaptive remodeling process is a disturbing phenomenon. The purpose of this study is to analysis the degree, the location and the time of appearance of femoral bone resorption after cementless total hip replacement and to evaluate the factors affecting the degree, the location and the time of appearance of bone resorption. The authors analysed total 48 cases of standard radiographies which underwent operation between September, 1983 to May, 1994 at Korea University, Guro Hospital and the mean duration of follow up was average 16 months(range 7 months to 5 years). The results were as follows; 1. Bone resorption could be observed mostly in proximal portion of femur and the extent was limited to the first and the second degree according to Engh’s classification in most cases. 2. The degree of bone resorption was significantly correlated with the diameter of femoral stem. 3. The time of appearance of bone resorption after THR was not statistically correlated with the diameter of femoral stem. 4. The degree of bone resorption was not related with sex, age, preoperative diagnosis, type of femoral stem and degree of press-fitting. In conclusion bone resorption as an adaptive bone remodeling process after cementless total hip replacement could be observed in the proximal femur, and the factors affecting the degree of bone resorption were closely related with the size of femoral stem, but not related with sex, preoperative diagnosis, press-fitting and type of femoral stem. From the mechanical point of view, we could conclude that the bending stiffness of a prosthesis was the most important factor affecting the degree of bone resorption.