Case 28 Answer

Answer: Pelligrini-Stieda Syndrome

Calcification at the femoral insertion of the medial collateral ligament typically seen a few weeks after the original trauma.

There are 2 distinct entities:

Pelligrini-Stieda lesion = the calcification itself. Can be connected or not to the femoral condyle and can be small or very large  - typically asymptomatic (more common)

Pelligrini-Stieda Syndrome = when patient is symptomatic at the site of this calcification (presumably due to the inflammatory nature)

Here is the X-ray and CT from 3 weeks ago:

No calcifications at that time. And note the thickened MCL on the CT c/w injury