You weren't specific enough about your 'knee bleed' for me to compare it to what I've experienced - and written about here a few times.
If this bleed is actually BEHIND your knee, it's probably the same thing that I've experienced a few times over the last four or five years. (One of these put me in the hospital for a few days last year).
What you may have had is called a 'Bakers Cyst.' It's also known as a Popliteal cyst. Fluid forms behind the knee, and you get a bulge that is filled with fluid, dried blood, and blood. It's hard to bend your leg all the way back. Occasionally, the thing pops, causing significant pain, and the fluids drip down the leg, creating some really beautiful (or ugly) bruises. At least, this is what I had a few years ago.
I used crutches for a few days. My orthopedist was no help.
Last November, I was sitting in a cardtable chair with my legs folded under me, playing Othello with a 99 year old nun. When I got home, I felt a cyst behind my left knee. It got worse as time went on. I called my orthopedic surgeon, he was of no help, it wasn't an emergency, and he really didn't care.
The next morning, my entire left calf was stiff, filled with fluid (I guess), and extremely swollen. He told me that he'll see me in two weeks.
He told me that he couldn't drain the cyst because there were nerves behind my knee that he didn't want to injure.
I called a rheumatologist. He was concerned about the turgidity of my calf. He could drain the fluid, but didn't want to until he saw an ultrasound of the knee and lower leg to see what was going on.
The lab I went to for the MRI was across the street from a hospital. They didn't have my appointment. Using a crutch, and stopping a few times to deal with the pain, I walked across the street to the hospital's emergency room. I asked for a wheelchair - I couldn't stand any longer.
In the hospital, they did an ultrasound of the veins in my leg. The E.R. doctor had me admitted - he was concerned that I may have 'compartment syndrome.' (Compartment syndrome can result in death of tissue and, in some cases, loss of the leg).
In the hospital, they had me sitting upright in the hospital bed. The swelling didn't resolve much. The hospital claimed (and I'm not sure if it's accurate) that my INR was 6.1. I take my INR weekly, but missed for a few weeks, and didn't test it after starting hyaluronic acid. So, it's possible that a higher INR contributed to the free flow of fluid into the synovial cyst, and the leakage of fluid into the lower leg.
I was in considerable pain for weeks (I know, if your suffering, this isn't good news), but it was releived by extractions of the fluid from the cyst, by the rheumatologist. He explained that Orthopedic surgeons aren't especially interested in things that aren't surgical. The Rheumatologist was able to extract the fluid. He also ordered an MRI -- revealing that when I had a fall a few months earlier, I'd torn some ligaments in my knee - completely missed by the Orthopedic surgeon - and, in his words, I'll need a knee replacement.
I ignored that advice. But once or twice a week, the rheumatologist drained the fluid behind my knee - offering almost immediate reduction in pain. I also made sure that my INR stayed below 3 (he didn't want to drain the fluid if my INR was higher, because it took longer to stop the bleeding).
Physical therapy helped a little. Going to the gym and building up the muscles around my knee seemed to help even more.
Keeping my INR below 3.5 is probably one of the ways to reduce the risk of another cyst forming. Making sure that I don't sit with legs behind me for more than 30 minutes or so, then walking around also helps.
If I were you -- I'd see a rheumatologist to assess your knee problem. If it's a cyst like I had, he or she may help relieve some of the swelling behind the knee.
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Now, another, somewhat related thing: I'm sitting here in a fair amount of pain. Last week at the gym, I overused one of their machines. This machine was designed to strengthen abdominal muscles. I kneel on it, knees together, body bent back further than it should be, and move my trunk from side to side, with weights causing restricted movement. Somehow on that damned machine, I either overstretched a ligament between my lower leg and my knee, or a popped a blood vessel.
My INR last night was 3.2 - well within range.
The large bruises on the inside of my leg, just below the knee are big and painful. The collected blood is distributing down to the lower calf, so I'm expecting to have a nice, big bruise on my lower calf in the next few weeks.
The point of this part is that I've got to be more careful with my knew found flexibility - folding my lower leg behind or close to the upper leg is a no no.
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So this is a long answer to a fairly short question.
You probably don't need knee surgery. You probably don't need a knee replacement (and if you do, you may be able to delay it). If your muscles above and below the knee are weak, you should try to strengthen all the muscles in your leg. You should watch your INR, keeping it in a safe range (for myself, 2.5-3.5 is fine).
And you shouldn't bend your lower leg under your upper leg, if you can avoid it, and certainly not for more than 30 minutes at a time.
