A single-dose spinal anesthesia combining with morphine for total knee arthroplasty (TKA) is a simple, economical anesthetic technique commonly used in our hospital. Still some patients could not get effective postoperative pain control. Pregabalin, an anticonvulsant, has been shown to reduce acute pain after molar extraction, laparoscopic cholecystectomy, and reduce postoperative morphine requirement after total hip arthroplasty, and celecoxib, a selective cyclo-oxygenase (COX) - 2 inhibitor, with perioperative prescription is successfully reduces pain score and opioid consumption after TKA under spinal anesthesia alone. However, no clinical study has yet investigated whether preoperative single-dose of pregabalin, celecoxib or in combination compared to placebo can improve analgesic efficacy of intrathecal morphine after TKA. The primary objective of this study was to evaluate whether these medications could reduce pain scores at rest / when movement and morphine requirement after TKA under spinal anesthesia with intrathecal morphine. Secondary outcome assessed include adverse effects, anxiety score and patients' satisfaction score.
To evaluate whether pregabalin and/or celecoxib could improve analgesic efficacy of intrathecal morphine for patients after total knee arthroplasty.