I'm a doctor (though I would trust a physio more than me!). Been interesting reading thread from start to finish and making my own provisionsal diagnoses as I go along. I don't do knee injections but my colleagues do. Can be difficult to predict if they will help. Some people have .months of benefit, others very little. Only real reason not to get it done is if you would have an operation in next 3 months as it affects healing.
Good luck and hope everyone else is on the mend
The injection did nothing at all for me, had it some time after my first operation. I've had 2 knee operations, a high tibial osteotomy that included another procedure to fill in a large part of my medial condyle that had broken away with synthetic plugs. This never worked, In no pain though, but can't run and my knee feels like a foreign body and is kind of numb. Sure one day it will just give up. On my feet 12 hours a shift at work. Now I'm older when it goes the next step would be a full knee replacement (which was told would've done in first place if I was older). Something want to avoid at all costs, as never felt pain as bad following the first operation. Then again I'm a bit of a wuss with pain.
Also had another operation to see why my knee hadn't healed and to remove the titanium plate that was fitted when my tibia was broken during the osteotomy, to see if this was causing issues. First operation was in 2010, so can't complain. Although the surgeon told me I'd be back up on the fells again in no time... Something simply can't do anymore. Can cycle (if not too hilly), swim, or row. Just have to make the most of what you've got really if possible with dodgy knee(s).
Hope other peoples get sorted without surgery, or without really invasive surgery. I always wear a decent knee support, find it hard work without one.