Tibial tuberosity_Acute Pain without trauma

Dear MSK-Friends,

here the responses to this case so far:

· In your Cor T2w image it appears that there is a thin rind of
bone along the deep surface of the osteochondral “body” lateral to the
ischial tuberosity, with flattening of the adjacent lateral facet….as if
it is a donor site.
It looks very much like a chronic avulsion.

I’m sure it is easier for you to see, but the proximal hamstring
tendon complex is either chronically avulsed or partially torn with
peritendinous or, perhaps, ischiofemoral bursal fluid, all contributing to
ischiofemoral impingement.

I vote old avulsion, no osteochondroma.

Perhaps the bursitis is acute….and that explains the old pathology with
new, acute symptoms.

· Haematoma related to semimem separation?

· Xray

· Could this be hydroxyapatite deposition/calcific tendinitis?

· Osteochondroma with surrounding soft tissue edema because of
conflict. Since cartilage cap is thick I would like to exclude low grade
chondrosarcoma. Low signal on T2 is slightly high on T1 so ok for bleeding
because of conflict. I would do a CT scan to confirm and send to bone tumor
surgeon.

· Interesting case! The T1 looks too bright to be a cartilage cap,
and the enhancement doesn’t look typical for a cartilage tumor. I think
the ischial bone excrescence is either an osteochondroma (without cartilage
cap) or old avulsion injury. I’d favor an osteochondroma because it
doesn’t seem to be occurring quite at where the hamstring inserts. I think
the adjacent rim-enhancing soft tissue lesion is an adventitial bursa
related to the ischial bone excrescence.

· I would also include ischiogluteal bursitis in differential.

Today we did the CT-Scan (see attached images). Patient has no pain at the
moment. The CT helps exclude crystal deposition disease and any soft tissue
calcification. I am convinced that there is a kind of friction with
creation of an adventitial bursitis and secondary rupture. This explains
the acute pain, which lasted only 1-2 day. But can we know for sure what
this origin of the bony protuberance is? Patient declines any fitting
trauma in the past, as far as she is remembering. Semimembranosus tendon
seems to insert posterior to the bony structure. Old avulsion injury or
osteochondroma? What should a radiologist recommend as next step?

Thank you very much for your help.

Have a great week.

Chris

Christos Loupatatzis schrieb am Freitag, 26. März 2021 um 14:45:05 UTC+1:

OCAD_Tibial-tuberosity_Acute-Pain-without-Trauma_MRI_CT.pdf