The Expression And Clinical Significance Of TLR4and5in Periprosthetic Tissues Of Loosened Total Hip Prosthesis

Objective: To evaluate the collection of TLR4、5and asptic/sepatic loosening of total hipprosthesis and explore the functional role of TLR4、5in the mechanism of periprostheticloosening around total hip prosthesis through determining the TLR4，5expression inaseptic periprosthetic interface membranes and sepitic interface membrane compared to thenormal synovial membrances aroud hip joint.Methods: For immunohistochemistry studies,37cases of aseptic interface membrane ofperiprosthetic tissues and16cases of septic interface membrane were obtained at revisionsurgery and from salvage of infected totally replaced hips, respectively.10cases of normalsynovial membrances were obtained from the patients with femoral neck fracture forcomparion. Samples were processed for immunohistopathologic SABC method todetermine the TLR4、5expression. All data was analyzed by SPSS19.0.Results:1. TLR4and5were mainly expressed in cytoplasm and membrane ofinlammatory cell, and can also be found little expression in vascular endothelial cells andfibroblasts. There were positive expression for TLR4and5in all aseptic loosening andseptic loosening. The TLR4and5expressed in aseptic interface membrane was found tobe increased higher than the comparison (P<0.05). The TLR4and5expressed in septicinterface membrane was also found to be increased higher than the comparison (P<0.05).There was no statistical difference in TLR4and5expression between aseptic looseningand septic loosening (P>0.05).2. In aseptic loosening, the expression of TLR4and5in periprosthetic interfacemembrane of cememted prosthesis was found no satistical difference with the biologicalprosthesis (P>0.05). In septic loosening, the expression of TLR4and5in periprostheticinterface membrane of cememted prosthesis was also found no satistical difference withthe biological prosthesis (P>0.05). 3. TLR4expression was increased higher than TLR5in both aseptic loosening and septicloosening (P<0.05). TLR4expression was not related to the expression of TLR5(P>0.05).Conclusion:1. The upregulation of TLR4and5in periprosthetic tissues of asepticloosening and septic loosening might be involved in the pathogenesis of prosthesisloosening of total hip replacement.2. TLR4and5-mediated loosening should be not directly related to the fixation manner ofprosthesis (cemented or cementless prostheses).3. There was no significant correlation in TLR4and TLR5expression, probably becauseTLR4and TLR5enagaed in prosthesis loosening through2independent pathways.