A pathological fracture is a lesion of the bone itself due to a primary or metastatic disease. Our normal bone is surrounded by dense bone cortex and cancellous bone, which is still relatively hard. However, if osteolytic lesions occur in the bone itself, or if distant metastatic tumors occur, these diseases can destroy, resorb, and dissolve our bone, resulting in a decrease in bone hardness. Fractures may occur under normal activity or minor violence. The basis of the fracture is that the bone first suffers damage, resulting in a change in shape or a reduction in the hardness of the bone. This leads to easy fracture, which is a characteristic of pathological fractures. Common diseases that cause pathological fractures are tumor-like diseases, such as aneurysmal bone cysts, abnormal bone fiber proliferation, or hyperparathyroidism. There are also primary tumors, such as giant cell tumor of bone, Ewing’s sarcoma, osteosarcoma, and metastatic cancers that metastasize from distant sites, such as lung cancer, prostate cancer, breast cancer, etc. After these malignant tumors metastasize to the bone, they can destroy the bone structure and cause fracture easily, which is pathological fracture.