Hello and hope you are doing well.
If the Baker's cyst is restricting movement it may need to be surgically corrected. For the arthritis conservative measures are weight loss, rest, ice, canes, bracing, physical therapy. etc. Also, nutrition supply should be considered, with chondroprotective agents (glucosamine & chondroitin phosphate, MSM, Omega-3). Glucosamine and chondroitin phosphate are unlikely to cause any drug to drug interactions with your other medications.