Pathological Fracture of the Humerus

In general usually pathological fractures are caused by an inadequate trauma to the bone, which is impaired by the underlying disease. Pathologic fractures can be caused by a variety of local and systemic disorders. Aggressive neoplastic or pseudo tumor-like bone lesions present the second most common reason for pathologic fractures following osteoporosis. In this context the bony lesions can be divided into benign, primary malignant and secondary malignant tumorous lesions such as sarcoma and bone metastases respectively. Referring to the location of these bony lesions the humerus is considered as one of the most common localization of benign bone tumors as well as of sarcomas (osteosarcoma, chondrosarcoma, Ewing’s sarcoma). Several primary tumors metastasize primarily in the liver and lungs but also very often in the skeletal system. The most frequently affected locations are the spine and pelvis followed by proximal parts of humerus and femur. Concludingly, besides the spine and the femur the humerus is one of the most common localizations of pathologic tumor associated fractures [1]. The proximal humerus is particularly prone to pathologic fractures because of its long arm of lever, high rotational forces of the surrounding muscles and the mostly spongiform metaphyseal bone [2]. A profound knowledge on the different causes of pathologic fractures, on diagnostics and therapeutical options is necessary for a successful treatment of this heterogenic disorder. This book predominately deals with pathologic fractures of neoplastic genesis because of the high incidence of tumor associated pathologic fractures.