Use of Etoricoxib Compared to Diclofenac in the Perioperative Treatment of Patients After Total Hip Arthroplasty

The primary aim of this study is to test if etoricoxib decreases the perioperative blood loss compared to diclofenac. Secondary questions to be explored are: * Does etoricoxib prevent Heterotopic ossification after Total Hip Arthroplasty as well as diclofenac ? * Do diclofenac and etoricoxib both reduce pain at rest and on movements? * Does etoricoxib compared to diclofenac reduce the amount of rescue medication (Oxycodon)? * Does etoricoxib improve gastrointestinal tolerability compared to diclofenac?