Primary Research Objective:

The primary objective of this study is to determine efficacy of periarticular parecoxib sodium in a multimodal cocktail versus intravenous parecoxib injections for pain management in total knee arthroplasty

Secondary Research Objective:

• To determine if perioperative use of parecoxib sodium was associated with improved clinical outcomes
• To evaluate the safety, in terms of adverse events; serious adverse events and tolerability of parecoxib sodium in periarticular injections in a multimodal cocktail

This is a multi-center, open label, parallel randomized trial designed to evaluate the efficacy and safety of periarticular parecoxib sodium compared to intravenous parecoxib sodium.

125 patients with primary knee osteoarthritis from 4 participating sites who meet inclusion/exclusion criteria will be enrolled into the trial. After initial screening, patients will attend clinic for baseline examination. Subjects will then randomly allocated to periarticular parecoxib sodium or intravenous sodium in ratio of 1:1. patients are observed at post-operative 6, 12, 24 hours, subsequently daily for 4 days and finally at 2 week follow-up

Inclusion Criteria:

• Patients with primary knee osteoarthritis on treatment and planned for unilateral total knee arthroplasty and on spinal/general anesthesia
• Subjects age more than 50 and less than 85 years
• Patients with body weight at least 50 kg and not more than 50%above ideal body weight
• Written informed consent obtained from patient or guardian

Exclusion Criteria:

• Female patients who are attempting to conceive/pregnant
• Known allergy or hypersensitivity to cocktail regime or to COX-2 inhibitors
• History of bleeding disorders or coagulation defect
• Patients with abnormal liver profile
• Patients with history of stroke or major neurological defect
• Patients with neuropathic pain/sensory disorder
• Patients with peptic ulceration or anticoagulant use within 1 month
• History of previous major knee surgery/trauma
• Patients with renal insufficiency
• History of revision total knee arthroplasty
• Patients with knee deformity > 20 degrees
• Patients planned for bilateral knee arthroplasty during the same setting
• Patients with significant bone loss requiring augmentation
• Patients with history of using NSAIDs 24 hours before the surgery