BACKGROUND: A new classification system for juxta-articular osteosarcoma around the knee joint was developed to allow biological reconstructions using distraction osteogenesis or frozen autograft containing tumors treated with liquid nitrogen. Type I: Tumor has metaphyseal extension to a maximum of 2 cm from the epiphyseal cartilage plate. Type II: Tumor extends to at least half the circumference of the epiphyseal ... Read more