A new cocktail formula with diprospan of local infiltration analgesia in primary total hip arthroplasty: A prospective, randomized, controlled, observer‐blinded study

Objective This study aimed to observe the analgesic effect of the cocktail formulation with diprospan during total hip arthroplasty (THA). Methods From September 2018 to April 2019, 120 patients undergoing primary unilateral THA were included in this prospective, randomized, observer‐blinded study. Patients were randomized into three groups, according to the different local infiltration analgesia (LIA) strategies: LIA with ropivacaine (the ropivacaine group, n = 40), LIA with a new cocktail containing ropivacaine, diprospan, and morphine (the cocktail group, n = 40), and the control group (n = 40). The primary outcomes included postoperative pain scores. The resting visual analogue scale (VAS) scores were measured at 2, 6, and 12 h after the surgery (a.m. and p.m.) on postoperative day (POD) 1, POD2, and the day of discharge. Movement VAS scores were assessed at 6 h, 12 h after the operation (a.m. and p.m.) on POD1, POD2, and the day of discharge. The secondary outcomes included opioid consumption, postoperative hospital stay, range of motion of the hip at discharge, patient satisfaction, and the results of the follow‐up. Results After the screening, 120 patients were randomized into three groups (40 patients in each group). All of the patients completed the trial. The resting VAS scores in the ropivacaine group and cocktail group at 2 h were lower than those in the control group (P