Please find some chair yoga videos that you may be able to do while your knee heals. Please note however I would recommend that you speak to your doctor before you do any exercise after surgery.
We also have some mindfulness videos that may enjoy as you recover and I have attached a few here. Stay healthy and hope you feel better soon.

https://grokker.com/mind/program/meditation-basics-with-andrew-johnson/5ecbc8da52fef32df52234ab
https://grokker.com/mind/program/mindset-for-greatness/59df979166a2db39cafc7013
https://grokker.com/mind/mindfulness/program/10-days-to-happiness/5dce76b4475902260c6ee0de