R A D I O L O G Y
HISTORY:
80 year old male presenting with bilateral hip pain.
RADIOGRAPHIC IMAGING:
A single frontal view of the pelvis demonstrates near diffuse coarsening of the bony trabeculae as well as cortical thickening, most notable in the pubic and ischial bones and proximal femurs bilaterally. There is thickening of the ileopectineal line. Mild acetabular protrusion is present. These findings are typical of Paget's disease.
DISCUSSION:
Paget's disease is a disease of unknown etiology where there is abnormal bone remodeling with simultaneous increased activity of osteoclasts and osteoblasts. It is usually seen in patients over the age of 55, more often in males. The pelvis is the most commonly affected bone. Other common sites include the femur, skull and vertebral bodies. It is often polyostotic and asymmetic.
There are three radiographic phases: active, inactive and mixed. In the active phase, osteolytic changes are seen, while in the inactive phase, sclerotic changes are seen. Most patients present in the mixed phase. Radiographic findings in the pelvis are described above. In the long bones, the disease always begins at one articular end and progresses towards the other end, sometimes creating a "candle-flame" or "blade of grass" appearance. Bowing is also commonly seen in the long bones. In the skull, lytic lesions are described as "osteoporosis circumscripta" while the mixed phase will give a "cotton-wool" appearance. Basilar invagination with narrowing of the foramen magnum can sometimes be seen. The vertebral bodies may have coarse trabeculation, a "picture-frame" or "bone within bone" appearance, or less commonly, as an ivory vertebra if entirely sclerotic.
Complications of Paget's disease include neurologic deficits and symptoms from nerve compression as well as pain which may arise from pathologic fractures ("banana" fracture in the long bone or compression fracture of the vertebral body), degenerative joint disease or malignant sarcomatous transformation.
REFERENCES:
1. Resnick D, Bone and Joint Imaging, WB Saunders Co., 1989
2. Manaster BJ, Handbook of Skeletal Radiology, Mosby Year Book Inc., 1997
3. Chew FS, Skeletal Radiology-The Bare Bones, Williams & Wilkins, 1997
4. Dähnert W, Radiology Review Manual, Williams & Wilkins, 1993
Case submitted by W. Rojratanakiat and S. Chang.