[Polyethylene wear in periprosthetic tissue of failed cemented total hip arthroplasties]

To elucidate the relationship between polyethylene wear and loosening of total hip arthroplasty, we observed grossly the periprosthetic tissues, polyethylene wear debris and polyethylene acetabular liners retrieved from 6 failed cemented total hip arthroplasties during revisions by means of polar light miscroscope and scanning electron microscope. The production mechanism of polyethylene wear debris from acetabular liner was analyzed together with its role in periprosthetic fibrosis and prosthetic loosening. Results showed the abrasion of two bearing surfaces interposed with third-body particles as called three-body abrasion was the main model of polyethylene wear. All inner surfaces of the liners appeared clear abrasive scratches and big flat debris were found in most of the retrieved tissues. Histologically, the wear debris of various sizes embraced by 1 or several polynuclear giant cells that were found not only great in number but also active in function. The implication is that three body abrasion is the key factor of high rate wear of the polyethylene liner and that polynuclear giant cell is acting as an important cellular component leading to the prosthetic loosening.