I would greatly appreciate if you could give me your views...

Basically, i used to be a professional footballer, up to 1 year ago when i injured my left cruciate ligament.

This has been the second time tht i have injured my cruciate ligament (ACL) and therefore 6 months ago i have just had a revision of it.
The first time that i have injured it, was 4 years ago, when i was 19 years old, and within 7 months - after a successful rehab i had played my 1st game, and had no problems since then.

However, about a year ago, i twisted the same knee, and firstly had an athroscopy, which confirmed the ruptured ACL, then i had a revision of the ACL.

The 1st 3 months of my recovery were very smooth.
However, from the 3rd month till today - 6 months, i have been having swelling problems.

My orthopaedic surgeon has aspirated the fluid (urine colour) three times and has given me steroid injections for the swelling.
I have gone to 3 other doctors - and all say the same thing - that my knee is completly stable and 'as stable as a rock'.

In the revision surgery, the surgeon opted to get a patella graft, from the other (right knee) - as the 1st time i had the patella tendon from the same knee.

However, i have had continual swelling problems, and even after the steroid injection, the next day it has swollen up for me. The swelling is not a lot but still enough for me not to carry on with my program.

Also if i put a lot of pressure on it - if i do a quads exercise with a good weight it will swell up more the next day.

So at the moment i have changed my recovery program - to straight leg exercises - as per physio - so as not to irritate the graft..
Also i have no PAIN in my knee..just the swelling.

My questions are - why is the swelling taking place ?
What can i do to get over the swelling - to have a normal knee again... ?

How long may it take.. ?