Femoral nerve block versus obturator nerve block for pain management after total knee replacement A randomized controlled trial protocol

Background: Several studies reported short-term analgesic efficacy of obturator nerve block (ONB), as in comparison with the femoral nerve block (FNB) in the treatment of postoperative pain after the total knee replacement (TKR). The optimal method remains under debate. The purpose of our current work is to compare the safety and efficacy of FNB and ONB for postoperative analgesia after TKR. Methods: This prospective, randomized, and controlled study was performed from January 2018 to December 2019. It was authorized via the Institutional Review Committee in NO.971 Hospital of the People's Liberation Army Navy (2019-PLAN-132). Two hundred patients were divided randomly into 2 groups, the control group (n = 100) and study group (n = 100). The experimental group received FNB and control groups received ONB. Primary outcome included pain at different time point (Visual Analogue Scale score of anterior knee pain at rest and in motion). The Visual Analogue Scale scores were marked by patients themselves on a paper with a graduated line starting at 0 (no pain) and ending at 10 (the most painful). Opioid consumption was converted to equivalents of oral morphine uniformly for statistical analysis. Secondary outcomes included the knee range of motion, the hospital stay length as well as the postoperative complications such as pulmonary embolism and deep vein thrombosis. Results: Table 1 will show the clinical outcomes between the 2 groups. Conclusion: This trial would provide an evidence for the use of different types of peripheral nerve blocks in TKR.