Femoral nerve block: Assessment of postoperative analgesia in arthroscopic anterior cruciate ligament reconstruction

Was femoral nerve block effective for pain control of medial opening-wedge high tibial osteotomy?: A single blinded randomized controlled study

BACKGROUND AND PURPOSE

Medial compartment femoro-tibial osteoarthritis (OA) is a common disease and opening-wedge high tibial osteotomy (OWHTO) is the common surgical procedure carried out for these patients. While most researchers are focusing on the surgical techniques during operation, the aim of this study is to evaluate the pain control effect of femoral nerve block (FNB) for OWHTO patients.

METHODS

In this prospective, single-center, randomized controlled trial (RCT) study, 41 patients were operated on by OWHTO for OA during 2017 to 2018. Twenty of them (group A) accepted epidural anesthesia with FNB and 21 patients (group B) only had their single epidural anesthesia. All blocks were successful and all the 41 patients recruited were included in the analysis and there was no loss to follow-up or withdrawal. Systematic records of visual analog scores (VAS), quadriceps strength, mean number of times of patient-controlled intravenous analgesia (PCIA), using of additional opioids or nonsteroidal anti-inflammatory drugs (NSAIDs), and complications were done after hospitalization. The Student t test and Chi-Squared test was used and all P values ≤.05 were considered statistically significant.

RESULTS

VAS scores at rest (3.48 ± 1.0 vs 4.68 ± 1.1) and on movemment (4.51 ± 0.6 vs 4.97 ± 0.8) decreased more in group A than group B with significance at follow-up of 12 hours. The quadriceps strength, consumption of additional opioids or NSAID injections and mean number of times that the patients pushed the PCIA button didnot differ significantly within each group.

CONCLUSION

This RCT study shows that FNB in patients undergoing OWHTO for unicompartmental osteoarthritis of the knee could result in significant reduction in VAS scores at 12 hours postoperatively.Research registry, Researchregistry4792. Registered April 7, 2019 - Retrospectively registered, http://www.researchregistry.com.

Effect of Preoperative Gabapentin With a Concomitant Adductor Canal Block on Pain and Opioid Usage After Anterior Cruciate Ligament Reconstruction

Background

An adductor canal block (ACB) and preoperative oral gabapentin have each been shown to decrease postoperative pain scores and opioid usage in patients undergoing anterior cruciate ligament (ACL) reconstruction.

Purpose/Hypothesis

This study evaluated the efficacy of preoperative gabapentin on postoperative analgesia in patients who received an ACB. We hypothesized that patients undergoing ACL reconstruction with an ACB who utilized a single dose of preoperative oral gabapentin would have decreased pain and opioid consumption in the 24 to 72 hours after surgery compared with patients who did not utilize gabapentin.

Study Design

Cohort study; Level of evidence, 3.

Methods

Between January and October 2016, patients at a single institution who underwent ACL reconstruction and received an ACB were identified. Patients who underwent surgery before May 2016 were placed in the control group, and patients seen after May 2016 received a preoperative dose of gabapentin and were placed in the gabapentin group. All patients completed a pain log via a smartphone application to record pain scores and opioid usage after surgery.

Results

A total of 74 patients were identified: 41 in the gabapentin group and 33 in the control group. There were no significant differences between groups in demographics and operative characteristics. There were no differences in pain scores on postoperative day 1 (gabapentin vs control: 5.53 vs 5.56; P = .95), day 2 (4.58 vs 4.83; P = .59), or day 3 (4.15 vs 3.87; P = .59). The mean opioid consumption in oral morphine equivalents was not different on postoperative day 1 (gabapentin vs control: 47.2 vs 48.1; P = .90), day 2 (29.9 vs 33.5; P = .60), or day 3 (17.4 vs 18.7; P = .80).

Conclusion

Preoperative gabapentin did not reduce pain scores or opioid usage in patients who received an ACB and underwent ACL reconstruction in this retrospective cohort study.

Quadriceps Strength Deficits After a Femoral Nerve Block Versus Adductor Canal Block for Anterior Cruciate Ligament Reconstruction: A Prospective, Single-Blinded, Randomized Trial

Background:

Peripheral nerve blocks, particularly femoral nerve blocks (FNBs), are commonly performed for anterior cruciate ligament (ACL) reconstruction. However, associated quadriceps muscle weakness after FNBs is well described and may occur for up to 6 months postoperatively. The adductor canal block (ACB) has emerged as a viable alternative to the FNB, theoretically causing less quadriceps weakness during the immediate postoperative period, as it bypasses the majority of the motor fibers of the femoral nerve that branch off proximal to the adductor canal.

Purpose/Hypothesis:

This study sought to identify if a difference in quadriceps strength exists after an ACB or FNB for ACL reconstruction beyond the immediate postoperative period. Beyond the immediate postoperative period, we anticipated no difference in quadriceps strength between patients who received ACBs or FNBs for ACL reconstruction.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 102 patients undergoing primary ACL reconstruction using a variety of graft types were enrolled between November 2015 and April 2016. All patients were randomized to receive an ACB or FNB before surgery, and the surgeon was blinded to the block type. All patients underwent aggressive rehabilitation without functional bracing postoperatively. The time to the first straight-leg raise was reported by the patient. Isokinetic strength testing was performed at 3 and 6 months postoperatively.

Results:

Data for 73 patients were analyzed. There was no significant difference in patient demographics of age, body mass index, sex, or tourniquet time between the FNB (n = 35) and ACB (n = 38) groups. The mean time to the first straight-leg raise was similar, at 13.1 ± 1.0 hours for the FNB group and 15.5 ± 1.2 hours for the ACB group (P = .134). The mean extension torque at 60 deg/s increased significantly for both the ACB (53.7% ± 3.4% to 68.3% ± 2.9%; P = .008) and the FNB (53.3% ± 3.3% to 68.5% ± 4.1%; P = .006) groups from 3 to 6 months postoperatively. There was also no significant difference in mean extension torque at 60 deg/s or 180 deg/s between the FNB and ACB groups at 3 and 6 months. There were no significant differences in postoperative complications (infection, arthrofibrosis, retear) between groups.

Conclusion:

Although prior studies have shown immediate postoperative benefits of ACBs compared with FNBs, with a faster return of quadriceps strength, in the current study there was no statistically or clinically significant difference in quadriceps strength at 3 and 6 months postoperatively in patients who received ACBs or FNBs for ACL reconstruction.