Question

X-ray of a 5 year old child is shown in the image. Bone mineral density is normal. Identify the condition.

• A. Rickets
• B. Scurvy
• C. Metaphyseal dysplasia
• D. Osteopetrosis

Hint:

Normal bone mineral density with subperiosteal haemorrhage and Wimberger ring on X-ray points to a vitamin deficiency disease.

Answer 1

The Correct Option is B

Step 1: Interpret the X-ray findings.
The X-ray of the knee shows: subperiosteal haemorrhage, scorbutic zone (Trummerfeldzone / zone of rarefaction), dense zone of provisional calcification (White line of Frankel), ring epiphysis (Wimberger's ring), and Pelken's spur. These are pathognomonic features of scurvy.

Step 2: Understand why bone mineral density is normal.
In scurvy, the primary defect is collagen synthesis failure due to Vitamin C deficiency. Mineralisation itself is not impaired (BMD is normal), unlike rickets where mineralisation is defective.

Step 3: Classic radiological signs of scurvy at the knee.
White line of Frankel: dense zone of provisional calcification at the metaphysis.
Trummerfeldzone (scorbutic zone): lucent band just proximal to Frankel line -- the zone of rarefaction.
Pelken's spur: lateral extension of the Frankel line forming a spur at the metaphyseal corner.
Wimberger's ring sign: ring of calcification around the epiphysis.
Subperiosteal haemorrhage: lifts the periosteum due to capillary fragility from collagen deficiency.

Step 4: Eliminate distractors.
Rickets: cupping, fraying, splaying of metaphysis; BMD is reduced; no Wimberger ring or Pelken spur.
Metaphyseal dysplasia: genetic widening of metaphysis without the scorbutic zones.
Osteopetrosis: marble-bone disease with diffusely increased BMD -- exactly opposite to this scenario.