Paget disease of bone is a focal disorder of bone metabolism that occurs in the aging skeleton. It is characterized by an accelerated rate of bone remodelling, resulting in overgrowth of bone at single (monostotic PDB) or multiple (polyostotic PDB) sites and impaired integrity of affected bone. Commonly affected areas include the skull, spine, pelvis, and long bones of the lower extremity. The majority of patients are asymptomatic. The diagnosis is usually made incidentally following a routine chemistry screen showing an elevated serum concentration of alkaline phosphatase of bone origin or an imaging study obtained for some other reason that shows pagetic changes in bone. Traumatic and pathologic fractures are the most common complications of pagetic lesions in the long bones. Femoral fractures are more frequent than tibial fractures. The most common femoral site is in the area below the lesser trochanter. Fractures are usually transverse and perpendicular to the cortex. They can be either complete or incomplete (fissure fractures). Fissure fractures tend to occur along the convex surfaces of the curved bones but may progress to become complete fractures over time. Fracture of pagetic bone may be associated with substantial blood loss.
Sagrario María Santos Seoane, Victor Arenas García, María Gallego Villalobos and Rocío Martínez Gutierrez