Polyethylene wear particles do not induce inflammation or gelatinase (MMP-2 and MMP-9) activity in fibrous tissue interfaces of loosening total hip arthroplasties.

摘要: In vitro and in vivo studies have suggested that polyethylene wear particles are the main cause for osteolysis prosthetic loosening. Elevated amounts of proteases including gelatinases (or matrix metalloproteinases MMP-2 MMP-9) been found fibrous tissue interfaces loosened total hip arthroplasties suggesting proteolysis plays a role osteolysis. The presence does not mean they active, because activity is highly regulated at post-translational level. We investigated whether two major active extracellularly associated with loosening, MMP-9, involved loosening non-cemented implants acetabular components. Eight interface tissues retrieved during revision were studied light electron microscopy by situ zymography to localize MMP-9 combination immunohistochemistry proteins. All contained large particles, either accumulations or dispersed extracellular intracellularly fibroblasts. Particles encountered association leukocytes. Inflammation was never found. restricted macrophages microvascular endothelial cells mainly outside areas where present. Our data indicate do induce activation leukocytes activity. Therefore, aseptic may be particle induced but initiated other mechanisms such as mechanical stress.