Paget's disease

Question 1

What is pagets disease

Answer 1

a chronic disorder which results in thickened, brittle and mis‐shapen bones.

typically it affects only one or a few bones and it affects approximately 4% of over 55 year olds and up to 10% of over 80s

. Viral infection (paramyxoviruses) and genetic defects have been implicated in the aetiology.

Increased osteoclast activity (possibly due to an exaggerated response to vitamin D) results in increased bone turnover.

Osteoblasts become more active to try to correct excessive. bone resorption. The osteoblasts form new bone however the new bone fails to remodel sufficiently and the resulting bone despite its increased thickness and bone density is brittle and can fracture easily.

Question 2

common areas it affects

Answer 2

pelvis, femur, skull, tibia and sometimes the ear ossicles (resulting in conductive deafness).

Question 3

symptoms

Answer 3

can be asymptomatic and present as an incidental finding on Xray.

It can also cause
-arthritis (if close to the joint)
-pathologic fractures
-deformity
-pain and high output cardiac failure
(due to increased blood flow through pagetic bone).

Question 4

investigations

Answer 4

Serum alkaline phosphatase is raised whilst calcium and phosphorus are usually normal.

Radiographic features demonstrate that the affected bone is enlarged with thickened cortices and coarse, thickened trabeculae with mixed areas of lysis and sclerosis.

Bone scans demonstrate marked increased uptake in the affected bone(s).

Question 5

treatment

Answer 5

bisphosphonates (which inhibit osteoclasts) or calcitonin if extensive lytic disease.

Joint replacement may be necessary and pathological femoral fractures should be stabilized with long intramedullary nails or plates.