EXPERIMENTAL EVALUATION OF A RESORBABLE INTRAMEDULLARY PLUG FOR CEMENTED TOTAL HIP-REPLACEMENT

In order to evaluate degradation kinetics and biocompatibility of a re sorbable poly(D,L-lactic acid) (PDLLA) plug for total cemented hip pro stheses, an experimental in vitro and in vivo study was carried out. D egradation rate studies were performed in Ringer solution and after in vivo plug implantation in the femoral medullar cavity of rabbits. In vitro biocompatibility was evaluated in murine fibroblast cell culture s. PDLLA plugs showed faster degradation kinetics in vivo than in vitr o. Histological evaluations showed that PDLLA completely disappeared i n vivo 26 weeks after implantation. Fibrous tissue in the medullar cav ity was observed at 13 weeks, but no histological changes were observe d after 26 weeks. Also, the in vitro tests showed good biocompatibilit y of the biomaterial. Our results show the possibility of considering this resorbable plug for clinical situations instead of the traditiona lly used plugs [polyethylene, poly(methyl methacrylate) or cancellous bone] due to its biocompatibility, degradation properties and simplici ty of use. (C) 1997 Elsevier Science Limited.