Biodegradation of pure magnesium and bone tissue reaction in rabbit femur 1 year results of 3D micro-CT monitoring and histological observation

Abstract

Pure magnesium and its alloys are biocompatible and biodegradable. In cardiovascular surgery, they have been experimentally applied for short-term use as tiny devices. Many studies have been performed on rats and mice using X-ray imaging and CT scanning. However, these small animals have a low radiation resistance and the lethal exposure dosage is small. In orthopedic surgery, fracture fixation using magnesium materials has high potential applicability. Although long-term stable fixation is required, few long-term animal studies have been performed. Therefore, many unclear issues still remain. Accordingly a long-term animal study was performed on Dutch rabbits to investigate the biodegradation of pure magnesium. Specimens implanted into rabbit femurs showed a volume reduction of 40-50% at 52 weeks. Bone resorption was observed in cancellous bone, and new bone formation and direct contact were partially observed. No magnesium hydroxide was observed in the surrounding area.