MSK Pathology - OP

Question 1

What is OP ?

Answer 1

A bone mineral density of greater than -2.5 StD’s below the mean BMD

Question 2

Aetiology Primary Type 1 ?

Answer 2

Postmenopausal OP - (females only).

Oestogen decreases and Osteoclast activity increases

Question 3

Aetiology Primary type 2 ?

Answer 3

Senile OP (Males and females)

Decrease synthetic/replicative ability of osteoblasts -> decreases osteoblast activity

Question 4

Aetiology Secondary ?

Answer 4

1. Endocrine (cushings, increase PTH, hyper and hypo thyroid etc.)
2. Pregnancy and lactation
3. Myeloma
4. Malnutrition/absorption
5. Drugs/alcohol
6. Immobility

Question 5

Pathogenesis ?

Answer 5

Increase osteoclast/decrease osteoblast function -> increase bone resorbtion = Porous bones and decreased BMD

Question 6

Morphology ?

Answer 6

Thinner trabeculae and fewer than normal

Question 7

Clinical features symptoms ?

Answer 7

Often asymptomatic until fracture.

Question 8

Clinical features complications ?

Answer 8

Fragility fractures (e.g. minimal trauma).

Vertebral compression fracture can -> spinal cord compression, Cauda Equina Syndrome.

Question 9

Investigations ?

Answer 9

1. Plain X-ray
2. BMD scan: essential for Lumbar spine + hip (optional for forearm)
3. Interpretation of T and Z scores

Question 10

Treatment and prevention ?

Answer 10

Bisphosphonates - monthly
or Stronium - inhibits bone resorption and stimulates CA- deposition

Weight bearing exercise