Have a look over some useful articles regarding the physiotherapy management of Knee OA.
Ottawa Panel evidence-based clinical practice guidelines for therapeutic exercises and manual therapy in the management of osteoarthritis.
Home based exercise programme for knee pain and knee osteoarthritis: randomised controlled trial
EULAR Recommendations 2003: an evidence based approach to the management of knee osteoarthritis: Report of a Task Force of the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT)