Abstract
At this time the majority of acetabular replacements in total hip replacement rely on bone ingrowth or bone ongrowth. Long term success has been well established but is this success the result of good luck or good management? Numerous systems exist with the simplest perhaps being that of the placement of a hemispherical cup in a hemispherically reamed acetabulum. Beyond this, a wide variety of added complexity exists with the presumption that these increased complexities provide improved stability and hence more secure primary and secondary fixation.
The computer model that has been established demonstrates the geometry of fixation of hemispherical cups as compared to rim fit cups and looks at the requirements of acetabular distortion before secure fixation can be achieved. The model attempts to explain why on some occasions an apparently ideally reamed acetabulum is not secure without some form of augmentation of fixation.
The model provides a basis for considering the various options of acetabular fixation.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
