My 78 year old mums knee

Hi Elaine, the bubble behind your Mum's knee sounds very much like a Baker's cyst. Not actually a cyst, but a sac behind the knee which, when suffering with arthritis, fills up with fluid. It's not painful usually, unless it bursts, then there is a lot of pain going down the back of the leg which can last for days. There's not much a doc can do, apart from draining it, but there is a strong possibility that it might come back.

I had a very large one before my tkr 4 months ago, the surgeon drained it during the op, but it was back in no time, and now is smaller, but a lot harder, and feels like he left a marble behind before stitching me up. I don't see him again until next month, so not sure what he can do. However, it is causing discomfort this time when I try to bend my leg as far as I want, and I do find my leg buckles on occasion.

I could be completely wrong, Elaine, but that's the only experience I've had with lumps behind the knee, and Baker's cysts are fairly common I understand. At your Mum's age, I can understand her being unstable, even arthritis is enough to cause that, without the lump.

Wish her luck with the MRI, and let us know the results - it might help others.

Denise from Oz

yes it does sound like bakers cyst, my sister has one, she's only 52, and in a worse state than me, her knees give way, both, very dangerous, they say they don't do anything for the cyst as it usually goes of its own accord ones knee is sorted, my sister is seeing reumatolagist oh dear excuse spelling, it's way to early,lol.  Monday ( tomorrow in fact) she's only been waiting 4months, its ridiculous, she has it everywhere, poor love, sounds like your mum needs, to be seen, maybe quite a bit quicker though. I have to say though my sister is in a lot of pain with her bakers cyst, so may be that isn't what your mum has.