| There is considerable interest in characterization of wear debris from ultrahigh molecular weight polyethylene (polyethylene) bearing components used in total joint replacement (TJR). To isolate polyethylene wear debris, tissue samples must be excised from regions adjacent to revised polyethylene implant components, followed by exposure to one of many available tissue digestion methods. Numerous studies demonstrate successful digestion, but the relative efficiency of each method is not clear. In this first chapter, a variety of conditions for tissue digestion were evaluated to provide a quantitative comparison of methods. Porcine and human hip tissues were exposed for 24 hours to basic, acidic or enzymatic agents, filtered and digestion efficiency calculated based on the percentage of initial to final tissue weight. Of the conditions tested, 5M NaOH, 5M KOH, 15M KOH or 15.8M HNO3 yielded the most complete porcine hip tissue digestion (<1% residual tissue weight). Proteinase K and Liberase Blendzyme 3 did not effectively digest tissue in a 24 hour period. Similar to results from the porcine dataset, human tissues digestion was most efficient using 5M NaOH, 5M KOH or 15.8M HNO3 (<1% residual tissue weight). To verify that particle surface modifications did not occur after prolonged reagent exposure, GUR415 and Ceridust 3715 particles were immersed in each solution for 24 hours. Overall, this study provides a framework for thorough and efficient digestive methods for polyethylene wear debris extraction. |
