Prototype of minimally invasive hip resurfacing endoprosthesis - bioengineering design and manufacturing

The resurfacing arthroplasty (RA) has become at present the most developed minimally invasive kind of all total arthroplasties, which is a result of the progress in biomaterials engineering, biomechanical design and surgical fixation methods achieved over the past decade. Despite the raising popularity of RA, which undergoes at present its renaissance, it still causes several clinical complications. In this paper, we present the most important result our research project (4T07C05629), finished in February 2008, which is the prototype of original minimally invasive endoprosthesis for total hip resurfacing arthroplasty (THRA). We propose the essential innovation in fixation technique of the RA endoprosthesis components in trabecular bone by means of the multi-spiked connecting scaffold, offering the possibility of totally cementless fixation and the physiological blood supply in trabecular bone of femoral head, which is not possible in contemporary used cemented RA endoprostheses. Moreover, the femoral component is designed to preserve the femoral neck and head blood vessels. The prototype of the new kind of hip resurfacing endoprosthesis was CAD-designed in the frames of the Rogala's international patent general assumptions [1]-[3], optimized on the basis of the preliminary biomechanical tests on the pre-prototypes, and manufactured in the Selective Laser Melting (SLM) of both CoCrMo powder and Ti6Al7Nb powder.