A study for mechanism and treatment of aseptic loosening in total hip arthroplasty -Biclogical activity of wear particles, pathoicgical role of parathyroid hormone related peptide (PTHrP) and the therapeutical effect of bisphospham

Our first year study revealed that PTHrP in joint fluid taken during revision total hip arthroplasty was concentrated ten or hundred times higher than that in normal serum and that the pseudmenbranous tissue，which have potential role for bone absorption，was stained positive by anti-PTHrP antibody。Because PTHrP has promoting function for bone absorption，it is strongly suspected that PTHrP relates to the loosening and associated osteolysis of total hip arthroplasty.Based on the results of this study，we have planned the second year experiment to investigate factors that introduce PHTrP.Although many factors are considered to be related to osteolysis associated with the loosening of total hip arthroplasty，polyethylene particle is pointed out to be the most important factor.Therefore，we have decided to investigate from this aspect。Because it was pointed out that the property of the wear particles of total hip articulation is different from that of the industrially crushed particl…More es，we made a plan of experiment using wear particles produced in the total hip articulation，and tried to extract polyethylene particles from psudomenbranous tissue.After trying various methods of extraction，the method described below was revealed to be the most practical and simple。The tissue was soaked in Xylene to solve PMMA and then soaked in HNO I D 23个D 2 and HCL solution.The solution was neutralized by buffer.Polyethylene particles were gathered by filter.There were two types of polyethylene particles in the tissue by SEM analysis.The first type is a fibril like shape with the length of 5.3 micron in the average and the second type is a spherical shape with the diameter of 0.2micron in the average。Although we were going to investigate whether macrophages，which had phagocytized these polyethylene particles，were stimulated and produced PTHrP，adequate amount of sample had not been collected because of the low incidence of revision arthroplasty。We are now collecting samples for investigation。Less：Less

Our first year study revealed that PTHrP in joint fluid taken during revision total hip arthroplasty was concentrated ten or hundred times higher than that in normal serum and that the pseudmenbranous tissue, which have potential role for bone absorption, was stained positive by anti-PTHrP antibody. Because PTHrP has promoting function for bone absorption, it is strongly suspected that PTHrP relates to the loosening and associated osteolysis of total hip arthroplasty. Based on the results of this study, we have planned the second year experiment to investigate factors that introduce PHTrP. Although many factors are considered to be related to osteolysis associated with the loosening of total hip arthroplasty, polyethylene particle is pointed out to be the most important factor. Therefore, we have decided to investigate from this aspect. Because it was pointed out that the property of the wear particles of total hip articulation is different from that of the industrially crushed particl … More es, we made a plan of experiment using wear particles produced in the total hip articulation, and tried to extract polyethylene particles from psudomenbranous tissue. After trying various methods of extraction, the method described below was revealed to be the most practical and simple. The tissue was soaked in Xylene to solve PMMA and then soaked in HNOィイD23ィエD2 and HCL solution. The solution was neutralized by buffer. Polyethylene particles were gathered by filter. There were two types of polyethylene particles in the tissue by SEM analysis. The first type is a fibril like shape with the length of 5.3 micron in the average and the second type is a spherical shape with the diameter of 0.2 micron in the average. Although we were going to investigate whether macrophages, which had phagocytized these polyethylene particles, were stimulated and produced PTHrP, adequate amount of sample had not been collected because of the low incidence of revision arthroplasty. We are now collecting samples for investigation. Less