Vergleichende Untersuchungen zur Nekrosebereitschaft des Kapselgewebes bei Arthrose und endoprothetischem Gelenkersatz

Abstract

Necrosis rates of newly formed capsula tissue (the number of newly formed capsular tissues with necrosis) were examined after the reoperation of 95 cemented and 11 uncemented total and cup endoprostesis, consisting of different artificial joint materials. A comparison was made to the joint capsular tissue of 492 patients with arthrosis. The necrosis rate shows a lack of statistical significance within the 2-yr-groups over a period of 12 yr and between the different types of prosthesis by using PMMA [polymethyl methacrylate]-bone cement. Therefore, it is assumed that a biological equivalence of the prosthesis wear products is reached. Necrosis can possibly develop from the sudden increased accumulation of PMMA-bone cement particles from the bone bed, caused by the loosening of the prosthesis. In comparison, the newly formed capsular tissue of the uncemented prosthesis, of which no necrosis was shown, is evidence that the development of necrosis is chiefly due the quantity of PMMA wear products present. Because of the difficulty of exactly identifying the PMMA-bone cement wear products, the toxicity of the PMMA-bone cement- that is well known and in agreement in recent literature- or its wear products continue to be of hypothetical value in the production of necrosis. This is in spite of the successful detection by the gaschromatograph of the highly toxic paratoluidine in PMMA-bone cement. On the basis of the high statistical significance of the rate of necrosis in comparing the arthrosis joint capsules (14.83%) to the newly formed capsules (73:100%) it is shown that the capsulare fibrosis and scar formation to the obliteration of the lymphatic vessels is of secondary importance.