Overview of Bone Metastases Bone is a common site of metastasis for malignant tumors, and autopsy results of patients with malignant tumors show an overall incidence of bone metastases of 32.5%. The incidence of bone metastases is about 35-40 times higher than that of primary malignant bone tumors and is a frequent problem for orthopedic surgeons. Clinical features Bone metastases are prevalent in middle-aged and elderly people, with a male to female ratio of approximately 3:1. Most cases are characterized by multiple bone destruction. The spine, pelvis and long bone epiphysis are the preferred sites of bone metastases. Common clinical manifestations include: pain (50%-90%); pathological fractures (5%-40%); hypercalcemia (10%-20%); spinal instability and spinal nerve root compression symptoms.