Adductor canal block with periarticular infiltration versus periarticular infiltration alone after total knee arthroplasty: A randomized controlled trial protocol.

BACKGROUND: Effective postoperative analgesia may enhance early rehabilitation after total knee arthroplasty (TKA). The purpose of this study is to perform a randomized controlled trial to compare the efficiency of adductor canal block (ACB) with periarticular infiltration (PAI) versus PAI alone for early postoperative pain treatment after TKA. METHODS: After institutional review board approval, written informed consent was obtained from patients undergoing elective TKA. Subjects were randomized into 2 groups as follows: adductor canal blockade with 30 mL of 0.5% ropivacaine and 100 mcg of clonidine. All patients received a periarticular infiltration mixture intraoperatively with scheduled and patient requested oral and IV analgesics postoperatively for breakthrough pain. The primary outcome was morphine consumption in the first 24 hours. Secondary outcomes included pain scores, morphine consumption at 48 hours, opioid-related side effects (post-operative nausea/vomiting, sedation scores), functional outcomes, quadriceps strength, and length of hospital stay. CONCLUSIONS: For the present trial, we hypothesized that patients receiving adductor canal block + PAI would have significantly lower morphine consumption and pain scores after surgery. TRIAL REGISTRATION NUMBER: researchregistry5490.