Study design
unstable psychiatric, allergy, dementia, drug abuse, kidney or hepatic disease
ALLERGY, PATHOLOGY
This study is a prospective, double-blinded RCT. It was approved by the Ethics Committee (R(AG)299/2017) and it was registered in clinicaltrials.gov (NCT03518450; submitted March 17, 2018). The present trial is reported in compliance with the CONSORT statement.From April 2018 to April 2019, patients who were listed to undergo an elective, unilateral, primary TKA at the Department of Orthopedic Surgery of our center (a level 1 healthcare institution) were screened for the study. The inclusion criteria were: (a) patients older than 18 years of age, (b) elective, unilateral, primary TKA, (c) operated in our center between April 2018 and April 2019 and (d) programmed to be the first surgery of the day. Exclusion criteria included: (a) revision knee surgery, (b) previous diagnosis of unstable psychiatric pathology, (c) dementia, (d) kidney or hepatic disease that contraindicated the use of NSAIDs and/or paracetamol, (e) allergy to any component of multimodal analgesia, (f) use of opioids greater than 30 mg of oral morphine equivalent daily dose (oMEDD) and g) history of drug abuse.Eligible patients were interviewed and provided with a printed information sheet. After written informed consent was obtained, the patient was assigned a participant number and the preoperative battery of tests was performed. Then, the participants were randomized into three experimental groups: FNB group (FNB-G1), distal FTB group (FTB-G2) and proximal ACB group (ACB-G3). The randomization and allocation were computer generated by a statistician not otherwise involved in the study. Sequentially numbered opaque envelopes with each participant intervention group were made. Once in the operating theatre, the assigned anesthesiologist opened the corresponding envelope with the designated group. Excluding the anesthesiologist, all other professionals and the patient were blinded to treatment allocation.