There is a herbal supplement, Glucosomine, which can assist in the repair of cartlidge. It can help 'tighten' up joints - I expect that your joint has been stretched with the separation. I think it helps lubricate the joint, and helps your body 'grow/repair' the cartlidge.
It can come in various forms in the health shop, sometimes they are marketed as 'joint' formula, others are just labelled 'Glucosomine'.
It is not an overnight fix, it may take a couple of months, but its natural. Make sure you take at least the maximum dose specified. I have heard it suggested that for the first month it can be worthwhile taking a double dose.
My other half, whose hobby is muscle repair, would suggest that you have a lot of scar tissue around the joint that needs massaging out by deep tissue massage - if you have not tried this already.
Glucosomine can be good for those skier knees as well.