I developed a unique new design for total hip femoral components, referred to as the lateral-flare internal collar (L-FIC). It distributes weight over the entire proximal femur by the addition of a lateral extension onto conventional designs. This new design, based on an improved understanding of hip biomechanics, was possible with advanced computer technologies such as three-dimensional finite element analysis, stress optimization programs, and virtual reality systems. These new technologies permitted improvements of the traditional model of hip biomechanics established in 1917 by John Koch, M.D. of Johns Hopkins University, specifically by more accurately and more completely including soft tissue forces. Limited by the technology of his time, Dr. Koch could not include the many muscle and soft tissue forces surrounding the hip. By including these soft tissue factors, particularly the ilio-tibial band (ITB) as a tension band lateral to the femur, I theorized that compression load weighed on the lateral aspect of the proximal femur rather than tension, as predicted by the Koch model.

Mathematical and computer models and laboratory testing have proven this prediction valid. More importantly, the L-FIC design for femoral components, predicted on my model, has been reported in international studies to more effectively distribute weight to the proximal femur than do conventional hip devices. As a consequence, unlike conventional cemented and noncemented total hip replacement (THR) devices which can lose 20% to 40% of proximal femoral bone mass within the first 24 mo following surgery, the L-FIC components have been shown densitometri cally to preserve 95+% of original bone in primary THR surgeries and regeneration of bone in revision THR surgeries where prior bone loss has occurred. This biologic acceptance and response to the L-FIC design holds great promise for total joint replacement and further substantiates the validity of the concept and model.