Tribology in Total Hip Arthroplasty

Karl Knahr completed his medical studies at the University of Vienna in 1971 and subsequently trained as an orthopaedic surgeon at the Orthopaedic University Clinic of Vienna. In 1988 he became Head of the 2nd Orthopaedic Department at the Orthopaedic Hospital, Vienna-Speising and in the following year he was appointed Professor of Orthopaedic Surgery at the University of Vienna. For more than a decade, Professor Knahr has been the Austrian National Delegate to SICOT (Société Internationale de Chirurgie Orthopédique et de Traumatologie), Treasurer of the Austrian Society for Orthopaedic Surgery, and Austrian National Delegate to EFORT. Since 2005 he has been a member of the EFORT Executive Committee. He is currently a member of the editorial boards of International Orthopaedics and the Archives of Orthopaedic and Trauma Surgery and previously served as an editorial board member for the Journal of Arthroplasty. Professor Knahr has published widely on the subjects of tribology and hip arthroplasty.

Basics in Tribology: Tribology of Hip Prostheses.- Biomechanics of Hip Arthroplasty.- Ceramic Hip Replacements: Wear behaviour affects the outcome - a tribological and clinical approach.- Tribology of metal-on-metal bearings.- Highly cross-linked polyethylenes. Ceramic articulations : Are noisy ceramic-on-ceramic hips linked to periprosthetic bone?- Noise emissions in total hip replacements, with an emphasis of ceramic-on-ceramic and ceramic-on-metal bearings and different articular sizes.- Head size in relation to noise occurrence in ceramic-on-ceramic bearings.- The squeaking phenomenon in ceramic-on-ceramic bearings. Metal articulations: Ceramic surface engineering of the articulating surfaces effectively minimizes wear and corrosion of metal-on-metal hip prostheses.- Retrieval wear analysis of metal-on-metal hip resurfacing implants revised due to pseudotumours. Polyethylene articulations: Polyethylene wear in total hip arthroplasty for suboptimal acetabular cup positions and for different polyethylene types.- Wear analysis of highly cross-linked polyethylene in total hip arthroplasty.- Rates of osteolysis in well-functioning alumina-on-highly cross-linked polyethylene bearing cementless THA in patients younger than fifty with femoral head osteonecrosis.- Osteolysis and aseptic loosening: Cellular events near the implant. Miscellaneous: Cushion form bearings in total hip arthroplasty.- A novel model to predict wear in an uncemented hip replacement with a ceramic on polyethylene bearing.- Comparative in vivo wear measurement of conventional and modern bearing surfaces in total hip replacements by the use of POLYWARE® computerized system.- Tribology of knee replacements: Low conforming polyethylene fixed bearingknees.