musculoskeletal and connective tissue disorders
Paget Disease of Bone
Pathophysiology of Paget Disease of Bone
Any bone can be involved in Paget disease. The bones most commonly affected are the pelvis, femur, and skull. Other less commonly involved bones are the tibia, vertebrae, clavicle, and humerus. Bone turnover is accelerated at involved sites. Pagetic lesions are metabolically active and highly vascular. Excessively active osteoclasts are often large and contain many nuclei. Osteoblastic repair is also hyperactive, causing coarsely woven, thickened lamellae and trabeculae. This abnormal structure weakens the bone, despite bone enlargement and areas of bone sclerosis. 