What can be done to straighten leg post op?

I had an acl replacement/repair approx. 19 years ago and it did the job!...allowed me to get back to playing rugby.

However I could never get my leg straight and has always had a fairly high degree of flexion (approx 5-10 degrees) which has always had some impact on the stability of the knee.

At the time of the operation I believe the 'wisdom' at the time was to keep the knee in a brace at a flex angle of approx 30degrees. My understanding, although no-one would admit to it, was that they left the brace on too long and hence I couldn't ever get my leg straight (again, not sure if this' true).....at the time I did everything possible to straighten it.

I'm suffering constant pain in it now (medial) and although I suspect it's cartlidge problems (yet again) - I wonder if anyone has had an op to straighten the leg/knee following such an op.........and what the outcomes where!?

Thanks,
James