I am a male 64 years age. 2 years ago I had developed knee pain which occurred quite suddenly while working at my computer in the office. Pain was initially on the right knee. After examination by an orthopedic doctor he advised me of arthroscopic surgery. I had undergone this surgery with subsequent physiotherapy for 6 months. During this time pain started in the left knee also. The doctor says it is arthritis. Now after the physiotherapy I am able to walk, but have lost the flexibility of both knees. (Cannot bend more than 90 degrees) I would like to know if there is any treatment to restore this flexibility other than knee replacement surgery.