Try it
Orthopaedics · Bone tumours: complication of osteochondroma
Sample itemA 14-year-old with a hard, painless lump near the fibular neck develops foot drop and loss of sensation over the dorsum of the foot. What is the most likely mechanism?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
C. Compression of the common peroneal nerve by an osteochondroma
An osteochondroma of the proximal fibula can compress the common peroneal nerve at the fibular neck and cause foot drop. Other complications include bursitis, fracture, and vascular compression with pseudoaneurysm around the knee. Excision relieves the compression.
Option by option
A. Compartment syndrome of the anterior compartment
Compartment syndrome is acute and painful, with a tense compartment and an obvious precipitant.
B. L5 radiculopathy from a prolapsed disc
A disc prolapse in a 14-year-old is rare and would not explain a focal fibular lump.
C. Compression of the common peroneal nerve by an osteochondroma (correct)
Correct. The nerve winds around the fibular neck and is exposed to pressure from the bony outgrowth.
D. Malignant transformation with nerve infiltration
Malignant change is uncommon in a young patient and does not usually present as foot drop.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.
More Orthopaedics questions
- Upper limb fracturesWhich complication is characteristic of a fracture through the waist of the scaphoid?
- Fractures in childrenA child with a displaced supracondylar fracture of the humerus develops a painful, pale…
- Bone tumoursA teenager has knee pain and a radiograph around the distal femur showing a sunburst per…
- HipA positive Trendelenburg sign is due to weakness of the gluteus medius and minimus. Whic…