Alternative bearing designs for hip resurfacing arthroplasty

Hip resurfacing is used as an alternative option for young patients suffering from osteoarthritis. Standard implants used for resurfacing have similar designs and biomechanical properties. We present a hip resurfacing system that restores the surface with minimal bone loss and preserves the subchondral bone stock of the femoral head by reaming the surface only without any bone resection and insertion of an onlay femoral cap. This technique is performed without guide pins or the need of navigation. No stem is used in the onlay resurfacing technique. The surface of the femoral component was designed using a biosurf structure, which achieved 14% less wear by reducing metal debris and increasing lubrication because of the biosurf-structured surface. The acetabular component is a modular system, which allows easier revision if required. Low viscosity cement is used for fixation of the femoral component. A cementless acetabular cup with trabecular metal structured surface is used, which is made of titanium-niobium, hydroxylapatit coated. A highly polished insert is placed into the cementless fixated socket. We also describe a modified minimally invasive anterolateral approach with complete prevention of any muscle resection.