Comparison of continuous femoral nerve block with local infiltration for postoperative analgesia in unilateral total knee arthroplasty- a randomized controlled trial

Abstract

Background & Objective: Local infiltration of knee joints during knee joint surgery has been used for postoperative analgesia with preservation of motor function of quadriceps muscle, which helps in early mobilization. Femoral nerve block has been incriminated with paralyses of vastus medialis muscle. We aimed to compare postoperative analgesia between femoral nerve block and local infiltration in patients undergoing unilateral total knee arthroplasty (TKA).
Methodology: After obtaining institutional ethical approval and written informed consent from the patients, this randomized controlled trial was conducted at Department of Anesthesia at Teerthankar Mahaveer Medical College & Research Centre between July - December 2018. The study was conducted on 60 patients of ASA I and II, undergoing unilateral total TKA. Patients were randomly divided into two groups: Group FB patients underwent femoral nerve block, and Group LI patients underwent local infiltration analgesia. Sedation score, numeric rating scale, motor power and frequency of nausea/vomiting were recorded and statistical analysis done.
Results: We observed better pain relief in patients which received femoral nerve block as compared to local infiltration analgesia (p < 0.001). Sedation score was higher in Group LI and was statistically significant between the two groups at 4th, 12th, and 48th hour (p < 0.05). Group FB patients were associated with higher muscle power grades (p < 0.001) as compared to local infiltration analgesia patients. Fentanyl demand was observed to be lesser in Group FB as compared to Group LI (p < 0.001).
Conclusion: The study concludes that femoral nerve block produces better pain reliefin patients posted for unilateral knee arthroplasty as compared to local infiltration ofthe local anesthetic solution. However, there is gross reduction in range of motion withfemoral nerve block.
Citation: Varshney RK, Prasad MK, Garg M. Comparison of continuous femoral nerve block with local infiltration for postoperative analgesia in unilateral total knee arthroplasty - a randomized controlled trial. Anaesth pain & intensive care 2019;23(3):268-273