The Analgesic Efficacy of Femoral Nerve Block and Popliteal Fossa Block After Knee Surgeries

Introduction: Postoperative pain after knee surgery affects the early postoperative joint mobility and rehabilitation of patients. Peripheral nerve block is an effective method to prolong the duration of postoperative analgesia and reduce need of systemic analgesic with less complications. We did the study of single-shot peripheral nerve stimulator (PNS)-guided FNB (femoral nerve block) and PNB (popliteal nerve block) with ropivacaine (0.25% and 0.375%) with an aim to compare the postoperative analgesic efficacy. Materials and Methods: Prospective, double blind, randomised comparative study of 50 patients of American Society of Anesthesiologists (ASA) Grade I–III aged 18–70 years posted for knee surgeries under spinal anaesthesia (SA) was done. Postoperatively both groups A and B received FNB (30 mL) and PNB (20 mL) with ropivacaine (0.25%) and (0.375%) respectively. Postoperative visual analogue scale (VAS) score at rest and on movement, total duration of analgesia and number of rescue analgesic required in 24 hours were noted. Results: Postoperative VAS score at rest at four hour was significant (5.0 + 1.4) in group A compared to group B (3.44 + 1.1) ( P < .05), while VAS on movement at two and four hour was significant (2.16 ± 1.78 and 5.24 ± 1.10) in group A compared to (1.32 ± 1.00 and 4.56 ± 1.1) in group B ( P < .05). Mean duration of analgesia was longer in group B ( P < .05) and total analgesic consumption in 24 hours was higher in group A ( P < .05). Conclusion: PNS-guided single-shot FNB and PNB improve quality of analgesia after knee surgery done under SA with ropivacaine 0.375% having longer duration of analgesia compared to 0.25% without much side effects.