BACKGROUNDNonsteroidal anti-inflammatory drugs (NSAIDs) have analgesic effects on femoroacetabular impingement (FAI) patients undergoing hip arthroscopy surgery (HAS). However, the influence of medication time on the analgesic effect of NSAIDs is uncertain. This study aimed to compare the analgesic effect, joint function, quality of life (QoL), and patients' satisfaction between preoperative and postoperative NSAIDs in these patients.METHODSIn this prospective, observational study, 165 FAI patients undergoing HAS with NSAIDs (celecoxib, meloxicam, and nimesulide) for analgesia were divided into preoperative (PRE-A) and postoperative analgesia (POST-A) groups according to their actual medication.RESULTSThe visual analog scale (VAS) pain scores on the 1st (P < 0.001) and 3rd (D3) (P = 0.015) days after the operation were lower in the PRE-A group versus the POST-A group but not preoperatively (P = 0.262) or on the 7th day after the operation (D7) (P = 0.302). The proportion of patients receiving rescue analgesia decreased in the PRE-A group versus POST-A group (P = 0.041). However, the modified Harris hip score (mHHS), proportion of patients with an mHHS ≥ 70, and EuroQol-5-dimensional score at preoperative, 1st month (M1), and 3rd month (M3) after the operation were similar between the groups (all P > 0.050). The VAS score on D7 was greater in the PRE-A group compared to the POST-A group (P = 0.014), but the scores at M1 and M3 and the satisfaction and very satisfaction rates at D7, M1, and M3 did not differ between the groups (all P > 0.050). Subgroup analysis revealed that the type of NSAID did not affect most outcomes.CONCLUSIONPreoperative NSAIDs elevate analgesic effect and patients' satisfaction, but not joint function or QoL compared to postoperative NSAIDs in FAI patients undergoing HAS.