FEMORAL BONE REMODELING IN HA COATED STEMS WITH 20 YEARS FOLLOW-UP

Abstract

Femoral stress shielding in cementless THA is a potential complication commonly observed in distally loading press-fit stems. This prospective study describes long-term femoral bone remodeling in cementless THA at a mean of 17 years (range: 15 to 20) in 208 consecutive fully HA-coated stems (Corail, DePuy Int. Ltd, Leeds, UK). All THA were performed by one group of surgeons between 1986 and 1991. The concept of surgical technique included impaction of metaphyseal bone utilizing bland femoral broaches until primary stability was achieved without distal press-fit. Radiographic evaluation revealed a total of five (2.4%) stems with periprosthetic osteolysis, which were associated with eccentric polyethylene wear. They were either revised or awaiting revision surgery. The remaining 97.6% stems revealed biologic load transfer in the metaphysis alone (52%) or in both metaphysis and diaphysis (48%). Stem survival of 97.6% after 15 to 20 years without stress shielding were considered to be related to: impaction of metaphyseal bone, bland broaches, HA coating, and unique prosthetic design.