MSK Q

[MudPhud20XX]

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Can we discuss this q?

A 2 yr old boy is brought to your office by his mother b/c the child is less active than other children of his age, and he appears weak. The family recently immigrated to the US. Physical exam is significant for lateral bowing of the legs. Chest palpation reveals beading along the anterior aspect. Which of the following changes in bone structure is most likely seen in this pt?

A. Osteoid matrix accumulation around trabeculae
B. Trabecular thinning with fewer interconnections
C. Subperiosteal resorption with cystic degeneration
D. Lamellar bone structure resembling a mosaic
E. Spongiosa filling medullary canal with no mature trabeculae

 

[Transposony]

Looks like it's from Kaplan QBank ?

 

[masaraksh]

I'll play (I'm not very good at medicine though)

My guess is A. bowing of legs/immigrant --> vitamin D deficiency --> low Ca2+ --> low bone mineralization --> more osteoid in the bone
B - trabecular thinning sounds like osteoporosis (or osteomalacia, I forget the difference)
C - ?? not sure what this describes. maybe osteomyelitis?
D - mosaic bone -- I think Pagets? its been a while.
E - ??? no idea, ewings?

 

[Focused1]

The answer is A : Osteoid matrix accumulation around trabeculae
The patient has Rickets which is common in people from developing countries because of insufficient dietary intake.
Because there is a deficiency of Vit D, the osteoid matrix remains un-mineralized.

Normally the bone formation process progressses in the following 2 steps:
Step 1: Osteoid Matrix made up of collagen and other fibers is produced
Step 2: Osteoid Matrix gets mineralized.

Here the osteoid matrix is formed but doesn't get mineralized becuase of hypovitaminosis.




Option B: Trabecular thinning with fewer interconnections : Osteoporosis

Option C: Subperiosteal resorption with cystic degeneration : Hyperparathyroidism : VonRecklinghausen disease of the bone.

Option D: Lamellar bone structure resembling a mosaic : Paget's disease


Hope it helps ! 🙂

 

[MudPhud20XX]

Looks like it's from Kaplan QBank ?

it's from UWorld : )

 

[MudPhud20XX]

Alright so the accumulation of osteoid matrix should hint you that the mineralization is lacking. Thanks guys!

 

[Transposony]

it's from UWorld : )

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