Not a Physio Eppo but FWIW with old ligament injuries and a bit of cold weather pain from old broken bones I got put onto "Ammeltz - Yoko Yoko" from Japan, a bit like the Goanna Liniment Oil and works great. You can buy it from chinese medicine stores or online if you'd prefer.
Treatment and strengthening wise, perhaps try some pool work like hydrotherapy, try limited range of motion and keep the muscle arthropathy to a minimum. If you get bored, maybe swim some laps freestyle or backstroke.
From recovering from numerous injuries over the years "Work within your comfort range, Not your pain range" recovering from injuries is Not a Competitive sport or activity.
Gell well soon.