Effect of Celebrex on preoperative pain in patients undergoing knee arthroscopy: a prospective randomized, double-blind, placebo-controlled trial

Objective To investigate the effect of Celebrex on the preoperative pain in patients undergoing knee arthroscopy. Methods From June 2012 to May 2013, 30 patients who would receive knee arthroscopy for simple acute or sub-acute knee injury were enrolled in the study after they had been accessed by Pittsburgh Sleep Quality Index (PSQI), Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale(SAS). They were 8 males and 22 females, aged from 15 to 59 years. They were evenly randomized into a Celebrex group and a vitamin C group (n= 15). The patients in Celebrex group took 200mg Celebrex twice a day from day 2 to day 4 after admission. Likewise, those in vitamin C group took vitamin C instead Visual Analogue Scale (VAS) was used to evaluate their resting and moving pain in the evenings of day 1 and day 4. At the same time, pain threshold and pain tolerance of both lower limbs were recorded by a pain-threshold machine. The 2 groups were statistically compared. Results In Celebrex group, there were statistically significant differences between pre-medication and post-medication in resting VAS (1.22±0.90 versus 1.00±0.81), moving VAS (4.23±1.38 versus 3.68±1.02), pain threshold of the normal lower limb (NL) (1.57±0.56 mA versus 1.79±0.51 mA), pain threshold of affected lower limb (AL) (1.33±0.48 mA versus 1.79±0.57 mA) (all P 0.05). In vitamin C group, the above comparisons were statistically insignificant (all P > 0.05). In Celebrex group, the variation values of moving VAS were significantly negatively correlated with those of pain threshold of the NL and AL (rNL = - 0.564, PNL = 0.028; rAL = -0.746, PAL =0.001). Conclusions Celebrex can reduce preoperative pain and increase pain threshold in patients undergoing knee arthroscopy, playing a role in preventive analgesia. There may be correlations between variations of pain and pain threshold before and after medication. Key words: Knee joints; Arthroscopy; Analgesics; Pain threshold