Medication
When taking painkillers for painful conditions it is very important to follow the guidelines for the recommended doses. Glucosamine is a health product and there is some evidence it reduces the rate of progression of arthritis seen on x-rays.
Injection
A steroid injection reduces inflammation but the effect only lasts for 4 to 8 weeks so it is not a lasting treatment. It can help with acute flare ups of rheumatoid and osteo-arthritis. Hyaluronic acid injections sometimes reduce arthritic pain for 6 months but the effect is unpredictable.
Weight loss
Weight loss reduces the load through the knee and reduces pain dramatically. In my practice several patients have lost a significant amount of pain and avoided knee replacement surgery.
Off-loading
The load taken by the knee can be reduced by using sticks or crutches. It can reduce load from 3 times to once body weight and provide pain relief. Sticks and crutches can also help with a feeling of instability. There are off-loader braces available which reduce the load going through a single knee compartment (in- or outside).
Kinetic chain
Anti-inflammatory measures
Ice is a natural and safe way to reduce inflammation. When a joint is swollen, painful and red regular ice application reduces symptoms effectively. Never put ice in direct contact with the skin. Non-steroidal anti-inflammatory medication can help reduce inflammation as well but care has to be taken in patients with asthma, heart disease and indigestion/stomach ulcers. Always consult a medical practitioner when in doubt.
Activity modification
Activity modification
When walking up to 3 times body weight is loaded through the knee, and 6 times when running. Changing activities from high impact (running, jumping) to low impact (walking, swimming and cycling) can reduce pain.
Knee support
Knee support
Elasticated knee supports sometimes help with a feeling of instability, but in general it is better not to rely on knee supports for longer periods. Hinged braces provide more stability but are more bulky and cumbersome.
Physiotherapy
Physiotherapists are good at looking for biomechanical problems, such as abnormal alignment, joint stiffness, muscle weakness and tightness. Correcting these issues can make significant difference in symptoms. For knees in particular muscle strength is essential.
The kinetic chain includes all bones, muscles and joints working together on a side of the body. For the knee it  involves the trunk and spine, hip, down to the ankle and foot. Correction of kinetic chain abnormalities can help knee symptoms. For instance with spine or hip arthritis the thigh muscle may be weak, leading to poor knee muscle support.
Non-operative treatment