Abstract
The significance of locus minoris resistentiae, which occurs in large foreign bodies such as artificial joints, is discussed with the review of 317 prosthetic replacements of the femoral head and 171 artifical total joint replacements carried out during these 12 years.
Three cases with infected femoral head prosthesis, who were all composed of compromised hosts, were enforced to remove the prosthesis infected by exogenous negative bacteria. Three cases with infected artificial knee joint, two of which were successfully managed without removal of the artificial joint, were suffered at a delayed or late stage after operation. One case in which the infected artificial knee joint was removed had many severe complications.
One case of total hip replacement has not suffered from postoperative infection during these 3.5 years, although a large amount of bacteria in the mucinous specimen taken from the surgical field were afterwards demonstrated by culture.
A twelve-year retrospective review of 2, 100 aged in-patients suffering from skeletal diseases yielded 22 cases with suppurative skeletal infections. On the other hand, the mean mortality of the aged patients by infection of other organs was 13% in the cases over 70 years old and 29% over 80.
Generally, risk of joint sepsis including that with artificial joints is not high, compared to the other organs such as respiratory or urogenital organs in the aged patients. Of the 6 cases with infected artificial joint, 4 cases with a compromised host were enforced to remove their artifical joints. To minimise the risk of postoperative infection of an artificial joint, it is important to take care of the artificial joint as a sanctuary having locus minoris resistentiae, but it is more important to control the associated diseases, namely minoris resistentiae generalis.
