[Pathologic bone fractures: definition and classification].

A bone fracture is a complete or incomplete discontinuity of bone caused by a direct or indirect force. A pathological bone fracture is a bone fracture which occurs without adequate trauma and is caused by a preexistent pathological bone lesion. Causes include resorption of bone mass (osteoporosis), reduction of bone quality (osteomalacia, osteonecrosis), insufficient bone production (osteogenesis imperfecta, fibrous dysplasia), augmented bone resorption (giant cell granulomas, aneurysmal bone cyst), pathological bone remodelling (Paget's disease), or local bone destruction due to tumorous growths. A pathological bone fracture has to be detected clinically as well as radiologically and its cause diagnosed histologically in order to ensure adequate therapy.