Efficacy of Etoricoxib 60 mg in Modifying Pain Hypersensitivity in People With Knee Osteoarthritis

Inclusion Criteria: * unilateral diagnosis of Knee OA \> 6 months * knee pain \> 4/10 on WOMAC pain subscale * if pain in contralateral knee, no greater than "mild" * no other significant joint involvement * ARA functional Class I, II or III * no arthroscopy or injections into index knee in last 6 months Exclusion Criteria: * history of systemic inflammatory or chronic pain disorders (especially fibromyalgia) * neurological deficit * recent (\< 6 months) lower limb surgery * allergic reaction to NSAIDs or aspirin * skin allergies, dermatitis * contraindications to Cox-2 inhibitors: * congestive heart failure (NYHA II-IV) * unstable hypertension * ischaemic heart disease * peripheral artery disease * cerebrovascular disease including CABG or angioplasty within 1 year * severe hepatic dysfunction * active GI bleeding or peptic ulceration * reduced creatinine clearance \< 30 mL/min * current use of high dose (\> 325 mg daily) aspirin