Paget’s disease of bone (PD) is a monostotic or polyostotic non-hormonal osteometabolic disorder. Over a century after the original disease was described by Sir John Paget1 in 1877, and despite recent intensive studies and widespread interest, its aetiology remains obscure. This review describes the pathomechanism of the structural changes
which occur in bone affected with PD, induced by the different dynamic patterns of activity of the disease, and outlines the current methods of treatment.