Adductor canal block with or without added magnesium sulfate following total knee arthroplasty: a multi-arm randomized controlled trial

Postoperative analgesia following total knee arthroplasty (TKA) often includes intrathecal opioids, periarticular injection (PAI) of local anesthetic, systemic multimodal analgesia, and/or peripheral nerve blockade. The adductor canal block (ACB) provides without muscle weakness and magnesium sulphate (MgSO4) may extend its duration. purpose this trial was to compare the duration quality early post-TKA in patients receiving postoperative ACB (± MgSO4) addition standard care. Elective TKA were randomized to: 1) sham ACB, 2) ropivacaine or 3) with added MgSO4. All received spinal anesthesia morphine, intraoperative PAI, analgesia. Patients assessors remained blinded allocation. Anesthesiologists knew whether had but primary outcome time first analgesic (via patient-controlled [PCA] iv morphine) ACB. Secondary outcomes morphine consumption, side effects, visual analogue scale pain scores, satisfaction until 24 hr postoperatively, length stay. Of 130 patients, 121 included. Nine excluded post randomization: four protocol violations, three did not meet inclusion criteria, two severe requiring open label There no differences median [interquartile range] PCA request: sham, 310 min [165–550]; 298 [120–776]; MgSO4, 270 [113–780] (P = 0.96). Similarly, we detected resting pain, opioid stay, associated effects postoperatively. We found benefit a undergoing an www.clinicaltrials.gov (NCT02581683); registered 21 October 2015.