A study on postoperative analgesic effects of intra articular ropivacaine and femoral nerve block in unilateral total knee replacement surgery

Introduction: Pain after total knee replacement surgery if not taken care of properly may interfere with early mobilization and recovery process. Infiltrating an anesthetic agent in the joint at the end of surgery is gaining popularity nowadays. So we compared the effects of intraarticular ropivacaine infiltration and single shot femoral nerve block for better post operative pain relief. Materials and Methods: 60 patients aged 50-75years Scheduled for unilateral total knee replacement surgery under spinal anesthesia were divided in 2 groups. Group I received 150 ml ropivacaine 0.2% (2mg/ml) as an intra-articular infiltration in knee and Group F received single shot femoral block with 0.25% ropivacaine 30ml after surgery. Pain intensity was measured on “Visual Analogue Score” at rest and during passive movement of limb. Rescue opioid consumption and weight bearing ability recorded in all patients for 24hrs postoperative. Results: Group I subjects had low pain score throughout post operative period (till 24 hours) as compared to group F at rest (p>0.05) as well as with passive limb movements (p<0.05). Average consumption of rescue opioid was less among group I (371.83mg ± 99.53) compared to group F (443.66mg ± 96.56) (p<0.05). 17 patients could stand on their feet within 24 hours postoperative in group I while only 8 from group F (p<0.05). Conclusion: Intra articular ropivacaine infiltration and femoral nerve block both provided similar analgesia at rest. However during passive movement of limb intra articular infiltration of ropivacaine provides better analgesia which decreased overall consumption of opioid and helped patients in bearing weight.