The effect of an intramedullary self-reinforced poly-L-lactide (SR-PLLA) implant on growing bone with special reference to fixation properties. An experimental study on growing rabbits

Polylactic acid (PLA) is a synthetic biodegradable material. The self-reinforced implants made of poly-L-lactic acid (SR-PLLA) were manufactured of biodegradable polymeric matrix reinforced with fibres of the same material. The purpose of this study was to find out the effect of an intramedullary SR-PLLA implant on growing bone and its applicability to the fixation of a femoral shaft osteotomy in a growing rabbit. In seven rabbits 6 weeks of age a SR-PLLA implant 2.0 mm in diameter and 50 mm in length was introduced into the intramedullary cavity of the right femur. A proximal femoral shaft osteotomy of the right femur was made in another ten 6-weeks-old rabbits. After accurate reduction, fixation of the osteotomy was achieved with an intramedullary 2.0 mm by 50 mm SR-PLLA-rod. The follow-up times were 6 and 28 weeks. An intramedullary SR-PLLA-rod neither caused any disturbance of the bone growth nor abnormalities of the peripheral blood cell counts. Solid union of the osteotomy was seen in six weeks afte...