Comparison of Ultrasound-Guided Femoral and Infrapatellar Nerve Block Effects after Anterior Cruciate Ligament Repair Surgery

Background: There are various protocols for pain management after anterior cruciate ligament (ACL) reconstruction surgery. Objective: This study aimed to compare two blocking protocols, including femoral nerve block (FNB) and infrapatellar nerve block (IPNB) in terms of pain severity, patient satisfaction, and muscle force preservation. Materials and Methods: This single-blind clinical trial study investigated the patients who underwent elective knee arthroscopic ACL surgery randomly either by ultrasound-guided FNB or IPNB. Subsequently, the patients were evaluated 1, 3, 6, 12, and 24 h following NB for pain severity, patient satisfaction level, and muscle force. Results: The pain score (both at rest and in flexion) was significantly lower in the first three h after the intervention in the FNB group. Moreover, the mean score of the patients’ satisfaction in the first hours was significantly higher in the FNB group after the procedure. Additionally, the IPNB group obtained a significantly faster mean time required for the first dose of opioid request. The mean dose of used opioids over 24 h was significantly lower in the FNB group. There was a significant difference between the groups in terms of the muscle strength score within 24 h; moreover, the FNB group obtained a significantly greater delay in muscle recovery. Conclusion: The FNB is associated with greater pain relief and satisfaction in patients who underwent arthroscopic ACL reconstruction surgery, compared to the IFNB technique. However, a further delay in the recovery of quadriceps muscle force is evident in the FNB group.