TISSUE REACTION ON PLLA VERSUS STAINLESS-STEEL INTERLOCKING NAILS FORFRACTURE FIXATION - AN ANIMAL STUDY

In order to develop a biodegradable interlocking nail for fracture fix ation, polylactic acid (PLLA) rods were implanted in the femoral bone of young pigs. A midshaft osteotomy was performed in order to mimic a fracture. The tissue response to PLLA rods versus stainless steel rods was studied after 1 and 3 months of implantation. Fracture-healing ch aracteristics and chemical and mechanical properties of the PLLA rods were studied after explantation. Mechanical properties deteriorated du ring implantation and chemical properties changed significantly in 1 a nd 3 months of implantation. PLLA and stainless steel induced a simila r tissue reaction during the studied implantation time of 3 months.