The study will be conducted in the Department of Clinical Pharmacology & Therapeutics and Department of Orthopaedics, after approval from the NIMS Institutional Ethics Committee. Study will be conducted as per the principles laid down by the declaration of Helsinki and in accordance with the ICH-Good Clinical Practice guidelines.   The study will be registered in CTRI. The study Patients diagnosed with Osteoarthritis of knee will be given patient information sheet, study procedure will be explained and written Informed Consent will be obtained.

At screening (Visit-1), demography data, detailed medical history, treatment history, general and systemic examination including vitals will be recorded.  8 ml of blood will be collected for estimation of CBP, RFT, LFT. X- ray knee joint/s Anteroposterior, lateral view will be taken. Assessment of pain, stiffness, physical function is done using WOMAC INDEX. It includes total of 24 items and three subscales, namely pain (5 items), stiffness (2 items), and function (17 items), scored on five-point ordinal scale, 0 - none, 1 - mild, 2 - moderate, 3 - severe, and 4 –extremely severe.¹² A structured case record form will be used to record all the patient specific details.

                   At visit 2, all the eligible patients will be asked to come to the department of clinical pharmacology and therapeutics and enrolled into the study. Any presenting complaints, General and systemic examination including vitals will be recorded. Simple Randomization method will be used. The random sequence will be generated using computer-generated random numbers in allocation ratio 1:1. Patients will be randomized into 2 groups. Group A will receive Polmacoxib 2mg once daily after breakfast in the morning, Group B will receive Aceclofenac 100mg + Paracetamol 325mg twice daily morning and evening after food. Treatment duration will be for 10 days. Patients who are on any other concomitant medication will be asked to continue the same and will be recorded in the Case Record Form. Tab Tramadol 50mg will be allowed as rescue medication in case patient complaints of pain. Patient diary will be dispensed to all the subjects and will be instructed to record the intake of study medications, rescue medication and any adverse drug reactions. Patients will be asked to report to the study site after 10 days for next visit.