Pain VAS score and severity in EPA group and POA group. EPA group presented lower pain VAS score at rest at 4, 8, and 12 h, but similar at −24, −2, 24, 36, and 48 h compared with POA group (A). EPA group exhibited decreased percentage of patients with moderate-severe pain at rest at 4, 8, and 12 h, while similar at −24, −2, 24, 36, and 48 h compared with POA group (B). EPA group presented lower pain VAS score at flexion at 4, 8, and 12 h, but similar at −24, −2, 24, 36, and 48 h compared with POA group (C). EPA group exhibited decreased percentage of patients with moderate-severe pain at flexion at 4, 8, and 12 h, while similar at −24, −2, 24, 36, and 48 h compared with POA group (D). Comparison between 2 groups was determined by the t test or Chi-square test. All repeated comparisons between 2 groups at different time points were corrected by the Bonferroni method. P < .05 was considered significant. ∗∗∗P < .001, ∗∗P < .01. AKS = arthroscopic knee surgery, EPA = early preoperative analgesia, NS = nonsignificant, POA = postoperative analgesia, VAS = visual analog scale.