Orthopaedic tumor surgery is a specialty that involves the diagnoses and treatment of primary benign and malignant tumors in the bones. The cause of bone tumors is unknown but most are non-cancerous (benign). A growing tumor may replace healthy tissue with abnormal tissue creating weakness in the bone and causing it to fracture. Enchondroma is one such tumour that originates from cartilage. However malignant tumours can spread cancerous cells throughout the body. Common primary bone cancers are multiple myeloma (bone marrow), osteosarcoma (knee, hip, shoulder), Ewing’s sarcoma (leg, pelvis, arm, ribs), and chondrosarcoma (hip, shoulder, pelvis) There are two types of bone cancer. Primary bone cancer begins in bone while secondary bone cancer begins somewhere else in the body, like the blood or the organs, and then spreads to the bone.