| Popis: |
Qualitative and semiquantitative features of the interfacial membranes of five long-term (16 years) surviving cemented total hip arthroplasties (four revision cases and one autopsy case) were compared with those of thirty short-term surviving (15 years) cemented hip prostheses. Cement granulomas, micron-sized polyethylene particles-induced giant-celled granulomas, sheets of submicron-sized polyethylene particles-laden macrophages, and aggregated, metallic particles-laden macrophages were scattered in the fibrous tissue of all interfacial membranes. Quantitatively, characteristics of the interfacial membranes of the two groups differed from one another. The dominant species of prosthetic debris in the interfacial membranes of the short-term surviving joint replacements was derived from the polyethylene acetabular socket, and, correspondingly, giant-celled granulomas and macrophagic sheets predominated. Metallic particles and the macrophagic reaction thereto dominated in the interfacial membranes of the long-term surviving arthroplasties, and large cement and polyethylene chunks typically were incorporated in the fibrous tissue of the membranes without an accompanying macrophagic response. In long-term surviving hip arthroplasties, metallic particles may be at least as important as polymeric detritus in stimulating the formation of the bone-resorbing, granulomatous interfacial membrane, which is the hallmark of aseptically loosened arthroplasties. Differences in mechanical settings may account for unlike modes and rates of generation of prosthetic breakdown products, explaining the disparate survivorship of different patients' artificial joints. |
