Pagets Disease

Question 1

What is Pagets disease of bone?

Answer 1

A conditoion where there is excessive bone resorption by osteoclasts followed by disordered laying down of poor quality bone by osteoblasts. The result is coarse, weak bones, which may bow or bend and are often painful.

It has 2 main phases, a lytic phase where bone resorption rate increases, and then a scleortic phase where bone formation overtakes. However this new bone is mechanically weaker and disorganised, with an increased chance of breaking.

Question 2

What will you find on a history taking of pagets bone disease?

Answer 2

Symptoms:
Commonly asymptomatic with a raised ALP found
Bone pain - at rest and at night
Pathological fractures
Skin over the affected bones is hot
Deformity - Bowed tibia, kyphosis, frontal skull bossing, enlarged maxilla, large head
Deafness and tinnitus due to ear ossicle being affected and impinging 8th cranial nerve

Risk Factors:
Old age

Question 3

What investigations will you order in Pagets Bone disease?

Answer 3

Bloods:
LFT's - Raised ALP 
Ca2+ - Normal
Parathyorid - Normal and rules out hyperparathyroidism 
Phosphorus - Normal

Imaging:
A classical V-shaped pattern between healthy and diseased long bones, known as ‘the blade of grass’ lesion.
Cotton Wool pattern on the skull

Special Tests:
Bone biopsy - Rule out bone cancer if suspected
Radionuclide bone scans can show the extent of the disease

Question 4

What is the treatment of Pagets bone disease

Answer 4

Lifestyle:
Walkers/sticks if legs affected
Calcium and Vitamin D supplements if low
Monitoring of ALP to assess treatment effectiveness

Medical:
NSAIDS and Paracetamol for pain relief
Bisphosphonates

Surgery:
To treat any deformity or complications