Femoral nerve block versus intra-articular infiltration: A preliminary study of analgesic effects and quadriceps strength in patients undergoing arthroscopic anterior cruciate ligament reconstruction

Background: Adequate analgesia and early rehabilitation is necessary for arthroscopic anterior cruciate ligament reconstruction (ACLR) surgery. Objective: To compare analgesia and quadriceps strength after femoral nerve block (FNB) with intra-articular infiltration (IA) using 0.25% bupivacaine for ACLR with patella tendon graft. Material and Method: Forty patients were randomized to receive FNB under ultrasound guidance with 20 mL of bupivacaine or IA with 15 mL of bupivacaine into the knee joint and 5 mL infiltrated along the incision sites including portal sites at the end of surgery. All patients received intravenous ketorolac at wound closure. Data regarding demographic, time to first pain, time to first morphine requirement, morphine usage, pain scores and quadriceps strength were recorded. Results: Significant difference in quadriceps strength was shown. Ninety percent of patients in Group IA and fifty-five percent of patients in Group FNB had good ability to extend knee at 24 hours after surgery (p = 0.013). No differences were found in demographic data, time to first pain, time to first morphine requirement, post operative pain scores and morphine consumption. Conclusion: The preliminary results demonstrated that IA has an effect on quadriceps strength less than FNB while provide comparable postoperative analgesia after patellar tendon graft ACLR.