Musculoskeletal Teaching FileMusculoskeletal Teaching File
Paget's Disease
AP view of the pelvis shows classic signs
of Paget's disease. On the radiograph of the pelvis, there is
evidence of thickening of the femoral neck and diffuse sclerosis
of bone. The trabecular bone is more thick than normal bone. The
lytic phase of the skull is described as cotton ball appearance
and classically known as osteoporosis circumscriptum. Furthermore,
the vertebral bodies are also enlarged and occasionally the one
is totally sclerotic, thus giving the appearance of an "ivory"
vertebral body.
Paget's disease is ideopathic and affects people living in high altitudes. It occurs in 3-5% of people over 40 years of age. The disease progresses in phases. Initially there is lytic destruction of bone by osteoclasts. Then this is followed by the production of new, abnormal bone by osteoblasts. The new bone is abnormal because it is woven bone, not trabecular, and is disorganized. The new bone also has an increase of blood vessels. This can result in high output heart failure. In the late stages, the bone in the pelvis, spine, or skull appears sclerotic and thick, yet it is susceptible to fracture and deformities.
Complications of Paget's disease also include malignant degeneration
and spinal cord compression. Malignant degeneration to osteosarcoma
occurs at a rate of 1-5% of victims. Spinal cord compression occurs
when the vertebral body grows large and compresses on the spinal
cord. It is important to distinguish between Paget's disease and
bone metastasis because they can both show increase in sclerotic
bone on X-ray.
Case prepared by Huan Nguyen and Cheryl Grigorian, MD