A pathologic fracture is a bone fracture caused by disease that led to weakness of the bone structure. This process is most commonly due to osteoporosis, but may also be due to other pathologies such as: cancer, infection, inherited bone disorders,or a bone cyst. Only a small number of conditions are commonly responsible for pathological fractures, including osteoporosis, osteomalacia, Paget's disease, osteitis, osteogenesis imperfecta, benign bone tumours and cysts, secondary malignant bone tumours and primary malignant bone tumours.