Tissue reaction on PLLA versus stainless steel interlocking nails for fracture fixation: An animal study

In order to develop a biodegradable interlocking nail for fracture fixation, 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 characteristics and chemical and mechanical properties of the PLLA rods were studied after explantation. Mechanical properties deteriorated during implantation and chemical properties changed significantly in 1 and 3 months of implantation. PLLA and stainless steel induced a similar tissue reaction during the studied implantation time of 3 months.