Case 53. Knee pain following a fall

This is a MR on a 60 y/o man w/ knee pain who had minor trauma (a fall) a week ago.

Coronal knee T1

Sagittal fibula

Sagittal T1

Coronal knee

Coronal fibula

Sagittal knee

What is going on with the marrow? Is it too early for RSD? All of the epiphyses are low on T1 and Bright on the PD and T2 F/S. We, of course, have no plain films. This is sort of the reverse of the pattern I would expect for normal reconversion, since it looks like the fatty marrow is metaphyseal and diaphyseal.

Let me know what you think if you have time. I am perplexed on this one. RSD or transient osteoporosis so focal, so soon? Trauma with contusion seems unlikely since the high signal is within the epiphysis and without subchondral change or effusion. They do not look like masses. Certainly not typical of marrow reconversion. I wasn’t much help here.