Hi,Dear,Welcome with your query to HCM.
Studied your query in full depth of its details.Reviewed it in context of your health concerns.
Based On the facts, You mostly seem to suffer from-Synovial thickening of the Left Knee.The fact that it causes burning pain- confirms it to be from 
Synovitis with 
arthritis.
Treatment-
Confirm the diagnosis from 
Second opinion by Ortho-pedic Surgeon / or 
by X-ray Knee/ or by CT knee study.
Arthroscopic Excision of the  Synovial Granulation thickening would give relief.
Conservative care by-quadri knee-exercises / NSAID/ VitD3 -
calcium supplements would help the recurence to be checked for long time
This reply would reduce your scare, hope so.
This reply would help you to plan further treatment soon with your treating doctors.Best of Luck and early recovery.
Welcome any further query in this regard,which would be replied in next 
session.
Good Day!!
Dr.Savaskar M.N.
Senior Surgical Specialist
M.S.Genl-CVTS