Metabolic Bone Disease – Radiology

Question 1

What is the main difference between osteoporosis and osteomalacia?

Answer 1

Osteoporosis – decreased bone mass

Osteomalacia – decreased bone mineralisation

Question 2

Describe the microstructure in osteoporosis.

Answer 2

Normal

Though there is an overall decreased quantity of bone

Question 3

What are the features of osteomalacia?

Answer 3

Too little mineral – osteopenic and soft bone bends and deforms
Too much osteoid – Looser’s zones
If calcium remains low –> secondary hyperparathyroidism

Question 4

What are Looser’s zones? Where are they found?

Answer 4

Narrow lucency, perpendicular to the bone cortex

Found in the pubic rami, proximal femur, scapular and lower ribs

Question 5

What is a distinctive feature of osteomalacia that can be seen in an X-ray of the vertebrae?

Answer 5

Codfish vertebrae – biconcave loss of height

Question 6

What radiographic feature is common to both osteomalacia andosteoporosis?

Answer 6

Osteopenia

Question 7

What is the key difference between osteomalacia and rickets?

Answer 7

Rickets occurs before the growth plates have fused

As the metaphysis grows most rapidly, it shows the most obvious changes

Question 8

What are the radiographic features of rickets that are linked to the metaphysis?

Answer 8

Indistinct frayed metaphyseal margin
Widened growth plate (no calcification taking place)
Bowing of weight bearing bones

Question 9

What are the main consequences of secondary HPT to bone?

Answer 9

Resorption and increased density

Question 10

Describe the radiological features of renal osteodystrophy.

Answer 10

 Subperiosteal bone erosions

 Brown tumours