Spinal implants - the problems of debris

[摘要] Wear debris are known to incite a variety of biological responses when released from a joint replacement device. One such response is known as osteolysis-pathological destruction of bone. Osteolysis is the major cause of failure in joint replacements. The loss of bone around a joint replacement may cause an aseptic loosening of the implant and reduce options for revision surgery. The intervertebral disc may be replaced with a joint replacement device. Often, this is done with a ball on socket joint using a metal-on-polymer material combination. Ultra-high molecular weight polyethylene (UHMWPE), inherited from hip and knee implants, is a common choice in lumbar disc replacements. The wear debris from a Charité implant, tested in vitro, was characterised using computer vision techniques and machine learning. It was found that wear debris from this UHMWPE and metal implant produce debris that are particularly prone to illicit an immune reaction that could lead to osteolysis. To counter the release of wear debris into periprosthetic tissue where it can do harm, laser sintered Polyetherketoneketone (PEKK) was wear tested in an attempt to capture wear debris in the surface voids formed by the manufacturing process. Despite literature suggesting this could work, wear tests showed sintered PEKK is unsuitable as a bearing material.

[发布机构] University:University of Birmingham;Department:School of Engineering

[关键词] T Technology;TJ Mechanical engineering and machinery