Femoral nerve block vs adductor canal block after anterior cruciate ligament reconstruction under general anesthesia: A prospective randomized trial protocol

Comparison of genicular nerve block with adductor canal block for postoperative pain management in patients undergoing arthroscopic knee ligament reconstruction: A randomised controlled trial

Background and Aims

Genicular nerve block (GNB) is beneficial in early ambulation and faster patient discharge since it selectively blocks articular branches and is motor-sparing. This study aimed to compare the analgesic efficacy of ultrasound (US)-guided GNB with adductor canal block (ACB) in patients undergoing arthroscopic anterior cruciate ligament reconstruction (ACLR).

Methods

This randomised, double-blind study was conducted on 38 adults undergoing arthroscopic ACLR. Patients in Group GNB (n = 19) received US-guided GNB with 3 ml of 0.25% bupivacaine and 2 mg dexamethasone. Patients in Group ACB (n = 19) received US-guided ACB with 20 ml of 0.25% bupivacaine with 6 mg dexamethasone. Postoperative rescue analgesia was provided by intravenous Patient Controlled Analgesia (PCA) with morphine. The primary outcome was Numerical Rating Scale (NRS) pain scores over 24 h. The secondary outcome was the duration of analgesia and 24-h morphine consumption. The Chi-square test was used to test the statistical significance between categorical variables. Independent t-test or Mann-Whitney U test was used to compare continuous variables.

Results

NRS scores at rest and physical activity at 24 h were similar in both the groups (P = 0.429 and P = 0.101, respectively). The mean time to rescue analgesia was comparable in both groups (Group GNB: 820.79 [483.65] min [95% confidence interval {CI}: 603.31-1038.27] and Group ACB: 858.95 [460.06] min [95% CI: 652.08, 1065.82], P = 0.805), and the mean 24-h morphine consumption was also comparable in both groups (P = 1.000).

Conclusion

US-guided GNB has an analgesic efficacy similar to US-guided ACB for patients undergoing arthroscopic ACLR.

A Practical Guide to Lower Extremity Nerve Blocks for the Sports Medicine Surgeon

BACKGROUND

Peripheral nerve blocks (PNBs) are vital in the administration of surgical analgesia and have grown in popularity for use in lower extremity arthroscopic procedures because of their capacity to safely and effectively control pain. The number and specificity of PNBs, however, have made choosing the best option for a procedure nebulous for orthopaedic surgeons.

PURPOSE

To present a narrative literature review of the PNBs available for arthroscopic hip and knee procedures that is adapted to an audience of orthopaedic surgeons.

STUDY DESIGN

Narrative literature review.

METHODS

A combination of the names of various lower extremity PNBs AND "hip arthroscopy" OR "knee arthroscopy" was used to search the English medical literature including PubMed, Cochrane Library, ScienceDirect, Embase, and Scopus. Placement technique, specificity of blockade, efficacy, and complications were assessed. Searches were performed through May 2, 2021.

RESULTS

A total of 157 studies were included in this review of lower extremity PNBs. Femoral nerve, lumbar plexus, sciatic nerve, and fascia iliaca compartment blocks were most commonly used in arthroscopic hip surgery, while femoral nerve, 3-in-1, and adductor canal blocks were preferred for arthroscopic knee surgery. Each block demonstrated a significant benefit (P > .05) in ≥1 of the following outcomes: intraoperative morphine, pain scores, nausea, and/or opioid consumption. Combination blocks including the lateral femoral cutaneous nerve block, obturator nerve block, quadratus lumborum block, and L1 and L2 paravertebral block have also been described. Complication rates ranged from 0% to 4.8% in those administered with ultrasound guidance. The most commonly reported complications included muscular weakness, postoperative falls, neuropathy, intravascular and intraneural injections, and hematomas.

CONCLUSION

When administered properly, PNBs were a safe and effective adjuvant method of pain control with a significant potential to limit postoperative narcotic use. While blockade choice varies by surgeon preference and procedure, all PNBs should be administered with ultrasound guidance, and vigilant protocols for the risk of postoperative falls should be exercised in patients who receive them.

Combined femoral-obturator-sciatic nerve block has superior postoperative pain score and earlier ambulation as compared to spinal anaesthesia for arthroscopic anterior cruciate ligament reconstruction

PURPOSE

Peripheral nerve blocks can be a suitable alternative to central neuraxial blockage, as the sole anaesthetic agent for better early postoperative outcomes, decreased hospital stay and earlier mobilisation after anterior cruciate ligament reconstruction (ACLR) surgery. The purpose of this study was to compare consciousness during the procedure, pain during early postoperative period (< 7 days), and perioperative outcomes following ACLR using combined sciatic, femoral, and obturator nerve blocks compared to the spinal anaesthesia.

METHODS

This was a prospective case-control study including patients between 18 and 55 years of age, with anterior cruciate ligament (ACL) injury confirmed clinically and radiologically and undergoing ACLR. Patients were allocated in the two groups alternatively, group 1 included patients who received combined nerve blocks, and group 2 included patients who received spinal anaesthesia for the surgery. The sensory effect, motor effect, adequacy of anaesthesia, perioperative analgesic use, duration of stay, postoperative pain (visual analogue scale 0-10 cm) and functional outcomes were noted.

RESULTS

There were 60 patients in each group. A total of seven patients in group 1 (11%) and two patients in group 2 (3%) needed conversion to general anaesthesia (n.s.). In group 1, out of 53 patients who underwent surgery, 26 patients had no perception of surgery in the joint, 17 patients had perception of manipulation of the knee joint, 4 patients had sense of touch, and 6 patients had sensation of pain in the knee (VAS scale less than 3). In group 2, out of 58 patients, 42 patients had no perception of surgery, 12 had a perception of manipulation of the knee joint, 2 had sense of touch, and 2 had sensation of pain in the knee. Blockage of sensory effect was significantly better in group 2 (p = 0.0001). However, the motor effect was comparable between the two groups (n.s.). Group 1 had significantly better pain scores 6, 12, and 18 h after the surgery. Moreover, patients in group 1 also had faster ambulation (mean difference of 5.5 h, p = 0.0001) and reduced hospital stay (mean difference of 8.4 h, p = 0.0001).

CONCLUSION

Combined sciatic, femoral, and adductor canal block is an effective sole anaesthetic modality for ACLR. The sensory effect was inferior when compared to spinal anaesthesia but sufficient for the procedure without the need for supplementation with any other anaesthetic modality. Patients receiving this combined nerve block had lesser early postoperative pain scores, earlier ambulation, and shorter hospital stay as compared to the spinal anaesthesia.

LEVEL OF EVIDENCE

Level 3.