pagets disease of bone

Question 1

define pagets disease

Answer 1

A disease of excessive, uncontrolled bone turnover due to increased osteoclast and blast activity.

Question 2

pathophysiology of pagets disease

Answer 2

1. often starts with a focal lesion in one or more bones.
2. Osteoclast activity is increased in these lesions, and they are larger and have an increased number of nuclei.
3. Osteoblasts are then triggered to build more bone; however, this bone is architecturally disorganised and weak.
4. There is an imbalance of the resorption and building of bone, causing an increased bone mass but with less structural integrity.

Question 3

what is pagets disease characterised by

Answer 3

alternating sclerotic (building) and lytic (destroying) phases.

Question 4

what perpetuates the cycle of pagets disease

Answer 4

Locally produced IGF and M-CSF

Question 5

how many patients of pagets disease are symptomatic

Answer 5

Only ~5% of patients are symptomatic; therefore, it is mostly picked up incidentally.

Question 6

symptoms of pagets disease

Answer 6

Bone pain
Bone deformity
Fractures
Hearing loss

Question 7

neurological symptoms of pagets disease

Answer 7

• nerve compression of cn8 (deafness)
• hydrocephalus

Question 8

3 investigations for pagets disease

Answer 8

1. bloods
2. x ray
3. urinary hydroxyproline

Question 9

what is urinary hydroxyproline

Answer 9

a protein constituent of bone collagen, good marker of disease progression

Question 10

what do bloods for pagets disease find

Answer 10

• Raised alkaline phosphatase
• Normal calcium
• Normal phosphate

Question 11

what does x ray for pagets disease find

Answer 11

• Bone enlargement and deformity
  (well-defined osteolytic lesions)
• Cotton wool appearance of skull
• Osteoporosis circumscriptaof the skull (poorly defined patchy areas of high and low bone density).

Question 12

first line treatment for pagets disease

Answer 12

Bisphosphonates

Question 13

other treatment options for pagets disease

Answer 13

• Calcitonin (used if bisphosphonates are unsuitable)
• Analgesia for bone pain
• Calcium and vitamin D, if necessary
• Surgery (rarely required to treat fractures, severe deformities, and arthritis)