Background: Acute pain is one of the main complaints of patients after total knee arthroplasty (TKA), which causes delayed mobility, increased morphine consumption, and subsequently increased costs. Therefore, the present study was performed to evaluate the preventive effect of preoperative celecoxib and gabapentin on reducing patient pain as a primary outcome after TKA surgery.

Materials and methods: This randomized, double-blind controlled clinical trial was performed on 270 patients with osteoarthritis that were candidates for TKA surgery allocated into three groups. In the first group, 900 mg of gabapentin was administered orally on a daily basis for 3 days before surgery. In the second group, 200 mg of oral celecoxib was administered twice daily for 3 days before surgery. In the third group, oral placebo was administered twice daily for 3 days before the surgery. The patients' pain score and knee and its functional score were recoded.

Results: The mean of reduction pain in gabapentin and celecoxib groups was significantly lower than that of the control group at 12, 24, and 48 h after surgery (P < 0.001); however, two groups were not significantly different from each other (P > 0.05). Furthermore, the two medication groups were not significantly different in this regard (P > 0.05). In addition, the knee score in the gabapentin group with the means of 85.40 ± 5.47 and the celecoxib group with the means of 87.03 ± 3.97 were significantly higher than those of the control group with the means of 78.90 ± 4.39 in the 1^st month after the surgery (P < 0.001).

Conclusion: According to the results of the present study, the preventive administration of gabapentin and celecoxib showed a significant and similar effectiveness on reducing patient pain after TKA surgery and on improving the KSS and quality of life scores.