ObjectiveTo investigate the effectiveness of preemptive analgesia with imrecoxib on analgesia after anterior cruciate ligament (ACL) reconstruction. MethodsA total of 160 patients with ACL injuries who met the selection criteria and were admitted between November 2020 and August 2021 were selected and divided into 4 groups according to the random number table method (n=40). Group A began to take imrecoxib 3 days before operation (100 mg/time, 2 times/day); group B began to take imrecoxib 1 day before operation (100 mg/time, 2 times/day); group C took 200 mg of imrecoxib 2 hours before operation (5 mL of water); and group D did not take any analgesic drugs before operation. There was no significant difference in gender, age, body mass index, constituent ratio of meniscal injuries with preoperative MRI grade 3, constituent ratio of cartilage injury Outerbridge grade 3, and visual analogue scale (VAS) score at the time of injury and at rest among 4 groups (P>0.05). The operation time, hospitalization stay, constituent ratio of perioperative American Society of Anesthesiologists (ASA) grade 1, postoperative opioid dosage, and complications were recorded. The VAS scores were used to evaluate the degree of knee joint pain, including resting VAS scores before operation and at 6, 24, 48 hours, and 1, 3, 6, and 12 months after operation, and walking, knee flexion, and night VAS scores at 1, 3, 6, and 12 months after operation. The knee injury and osteoarthritis score (KOOS) was used to evaluate postoperative quality of life and knee-related symptoms of patients, mainly including pain, symptoms, daily activities, sports and entertainment functions, knee-related quality of life (QOL); and the Lysholm score was used to evaluate knee joint function. ResultsAll patients were followed up 1 year. There was no significant difference in operation time, hospitalization time, or constituent ratio of perioperative ASA grade 1 among 4 groups (P>0.05); the dosage of opioids in groups A-C was significantly less than that in group D (P<0.05). Except for 1 case of postoperative fever in group B, no complications such as joint infection, deep vein thrombosis of the lower extremities, or knee joint instability occurred in each group. The resting VAS scores of groups A-C at 6 and 24 hours after operation were lower than those of group D, and the score of group A at 6 hours after operation was lower than those of group C, and the differences were significant (P<0.05). At 1 month after operation, the knee flexion VAS scores of groups A-C were lower than those of group D, the walking VAS scores of groups A and B were lower than those of groups C and D, the differences were significant (P<0.05). At 1 month after operation, the KOOS pain scores in groups A-C were higher than those in group D, there was significant difference between groups A, B and group D (P<0.05); the KOOS QOL scores in groups A-C were higher than that in group D, all showing significant differences (P<0.05), but there was no significant difference between groups A-C (P>0.05). There was no significant difference in VAS scores and KOOS scores between the groups at other time points (P>0.05). And there was no significant difference in Lysholm scores between the groups at 1, 3, 6, and 12 months after operation (P>0.05). ConclusionCompared with the traditional analgesic scheme, applying the concept of preemptive analgesia with imrecoxib to manage the perioperative pain of ACL reconstruction can effectively reduce the early postoperative pain, reduce the dosage of opioids, and promote the early recovery of limb function.