“…n In ltration of bone sarcomas into joints occurs in 3 ways, namely: 1) penetration through the joint cartilage, 2) extension around the articular cartilage beneath the joint capsule, and 3) via intraarticular structures, such as through an osseous-tendinous junction of an intraarticular ligament (Simon and Hecht 1982, Sato et al 1993, Schima et al 1994. However, transarticular spread of tumor cells to the opposite side of the joint is uncommon except in the sacroiliac joint (Abdelwahab et al 1991, Ozaki et al 1997b, Drnovsek et al 1999.…”