A randomized controlled trial comparing the efficacies of ketorolac and parecoxib for early pain management after total knee arthroplasty

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to reduce pain after orthopedic surgery. Currently, selective COX-2 inhibitors can provide effective pain reduction with less platelet inhibition compared with conventional NSAIDs. We aimed to compare the analgesic effect and perioperative blood loss (PBL) after total knee arthroplasty (TKA) between ketorolac and parecoxib administration.

We conducted a prospective randomized controlled study of 100 unilateral TKAs. The ketorolac group of 50 patients received an intraoperative periarticular injection (PAI) with 100 mg of bupivacaine and 30 mg of ketorolac. Afterwards, 30 mg of ketorolac was intravenously injected every 12 h until 48 h. In the parecoxib group of 50 patients, 20 mg of parecoxib was added to PAI, and the first intravenous dose was 20 mg followed by 40 mg every 12 h. The primary outcomes were visual analog scales (VASs) of postoperative pain, amount of morphine consumption, PBL, and blood transfusion rate.

The ketorolac group had a significantly lower VAS pain score than the parecoxib group at 6 h after TKA (2.38 ± 2.52 vs. 4.12 ± 2.86, P < 0.01). Thereafter, the VAS of both groups and total morphine consumption at 24 and 48 h were comparable. The PBLs of the ketorolac and parecoxib groups were 529.72 ± 263.02 and 402.40 ± 191.47 ml, respectively ( P = 0.01). However, the blood transfusion rates between groups were not different.

Parecoxib provides comparable analgesic effects to ketorolac. Additionally, perioperative use of parecoxib is safe and is associated with significantly less blood loss after TKA.