Usefulness of lateral femoral cutaneous nerve block in combination with femoral nerve block for anterior cruciate ligament reconstruction: a prospective trial

Periarticular cocktail injection is more useful than nerve blocks for pain management after anterior cruciate ligament reconstruction

Background

Anterior cruciate ligament (ACL) reconstruction is commonly associated with moderate-to-severe postoperative pain. Notably, various pain control strategies, a femoral nerve block (FNB) with a lateral femoral cutaneous nerve block (LFCNB), adductor canal block (ACB) with LFCNB, or periarticular cocktail injection (PI), have been investigated. However, no studies compare the effects of FNB with LFCNB, ACB with LFCNB, and PI for pain control after ACL reconstruction. This study aimed to evaluate the impact of FNB with LFCNB, ACB with LFCNB, and PI for pain relief in the early postoperative period after ACL reconstruction.

Methods

This retrospective controlled clinical trial enrolled 299 patients who underwent primary ACL reconstruction at our hospital between April 2016 and October 2022. We categorized these cases into groups based on the use of PI (PI group), FNB with LFCNB (FNB group), and ACB with LFCNB (ACB group) for pain management. We selected 40 cases each, with matched age, sex, and body mass index (BMI) from each group, resulting in 120 cases for analysis. In the FNB and ACB groups, 0.75% ropivacaine 15 ml was injected under ultrasound guidance preoperatively. In the PI group, a mixture of 0.75% ropivacaine 20 ml, normal saline 20 ml, and dexamethasone 6.6 mg was injected half at the start of surgery and the rest just before wound closure. Patient demographics (age, sex, height, body weight, and BMI) and surgical data (the requirement for meniscal repair, operative time, and tourniquet inflation time) were analyzed. After ACL reconstruction, patients' numerical rating scale pain scores (NRS) (0-10) were recorded at 30 min and 4, 8, 12, 24, 48, and 72 h postoperatively. NRS were then compared among the three groups using analysis of variance. In addition, within each group, these data were compared between the NRS ≥7 and NRS ≤6 groups using a t-test.

Results

There were no significant differences in patient demographics and surgical data. Pain scores were significantly higher in the PI group than in the FCB and ACB groups 30 min postoperatively, but they were lower at 12, 24, 48, and 72 h postoperatively. In the FNB group, there were no significant differences in the demographic and surgical data by NRS pain score. In the ACB group, the number of men was significantly higher in the NRS ≥7 group than in the NRS ≤6 group (p = 0.015). In the PI group, tourniquet inflation time was significantly longer in the NRS ≥7 group than in the NRS ≤6 group (p = 0.008).

Conclusions

Following ACL reconstruction using a hamstring autograft, periarticular cocktail significantly reduced early postoperative pain compared with nerve block combinations.

Outcome comparison of femoral nerve block and adductor canal block during anterior cruciate ligament reconstruction: adductor canal block may cause an unexpected decrease in knee flexor strength at 6 months postoperatively

INTRODUCTION

Peripheral nerve blocks are frequently used in anterior cruciate ligament (ACL) reconstruction. While femoral nerve block (FNB) has been associated with knee extensor strength reduction in the early postoperative period, no consistent view of knee extensor strength several months after ACL reconstruction exists. This study aimed to compare the impact of intraoperative FNB and adductor canal block (ACB) during ACL reconstruction on knee extensor strength at 3 and 6 months postoperatively.

MATERIALS AND METHODS

This retrospective study included 108 patients divided into FNB (70 patients) and ACB (38 patients) groups based on their postoperative pain management methods. Knee joint extensor and flexor strength were measured at 3 and 6 months postoperatively, using BIODEX at angular velocities of 60°/s and 180°/s. From these results, peak torque, limb symmetry index (LSI), peak knee extensor torque (time to peak torque and angle of peak torque), hamstrings-to-quadriceps (HQ) ratio, and amount of work were computed for two-group comparison.

RESULTS

There were no statistically significant differences in peak torque, LSI of knee extensor strength, HQ ratio, and amount of work between the two groups. However, maximum knee extension torque at 60°/s occurred significantly later in the FNB than in the ACB group at 3 months postoperatively. Additionally, the LSI of the knee flexor at 6 months postoperatively was significantly lower in the ACB group.

CONCLUSIONS

In ACL reconstruction, FNB may delay the time to peak torque for knee extension at 3 months postoperatively, which is likely to improve over the treatment course. In contrast, ACB may result in unexpected loss of knee flexor strength at 6 months postoperatively and should be considered with caution.

LEVEL OF EVIDENCE

Level III.

Ultrasound-guided adductor canal block is superior to femoral nerve block for early postoperative pain relief after single-bundle anterior cruciate ligament reconstruction with hamstring autograft

PURPOSE

This study aimed to compare the combination of a lateral femoral cutaneous nerve (LFCN) block with a femoral nerve block (FNB) and an adductor canal block (ACB) for postoperative pain control in patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring autograft.

METHODS

A non-randomized, prospective, controlled clinical trial was conducted. The FNB and ACB groups consisted of 41 and 40 patients, respectively. Thirty minutes prior to surgery, the patients received an ultrasound-guided LFCN block either with FNB or ACB. The following values were recorded and compared between the two groups: duration of surgery, pain management during surgery (including total amount of fentanyl administered), and numerical rating scale (NRS) scores at 30 min and 4, 8, 12, 24, 48, and 72 h after surgery. Factors affecting pain relief (NRS < 2) were evaluated, including block type, total amount of fentanyl administered, duration of surgery, age, sex, body mass index, and postoperative suppository use. Significant factors predicting pain relief were determined using the Cox proportional hazard regression model.

RESULTS

There were no significant differences in pain management during the surgery. Pain scores were significantly lower in the ACB group at 30 min, 4 h, 24 h, and 48 h after surgery. The Cox proportional hazard regression model identified ACB as a significant factor for pain relief (hazard ratio: 1.88; 95% confidence interval: 1.12-3.13; p = 0.018).

CONCLUSION

The combination of ACB with LFCN block during ACL reconstruction significantly reduced pain in the early postoperative period compared to FNB with LFCN block.

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.

Anterior cruciate ligament reconstruction with ultrasound-guided femoral nerve block does not adversely affect knee extensor strength beyond that seen with intravenous patient-controlled analgesia at 3 and 6 months postoperatively

BACKGROUND

This study aimed to investigate the effect of anterior cruciate ligament (ACL) reconstruction with an ultrasound-guided femoral nerve block (FNB) on knee extensor strength weakness 3 and 6 months, and graft rupture in the 1 year following ACL reconstruction.

METHODS

One hundred and seven patients who underwent ACL reconstruction were included in this retrospective study. The patients were divided into two groups stratified by the method of postoperative pain management. The FNB group included 66 patients, and there were 41 patients in the intravenous patient-controlled analgesia (iv-PCA) group. The isokinetic peak torque of knee flexor and extensor was measured preoperative, 3 and 6 months after ACL reconstruction. Muscle strength measurements were performed using the BIODEX dynamometer at a velocity of 60°/s and 180°/s. Peak torque of knee extensor and flexor strength, estimated pre-injury capacity (EPIC), body weight ratio (BW), and graft rupture incidence were compared between the two groups.

RESULTS

There were no statistically significant differences in the knee extensor and flexor strength for all items at 3 and 6 months after ACL reconstruction. There was also not a statistically significant difference in the graft rupture incidence between the two groups: FNB group was two patients, 3.0% vs. iv-PCA group was one patient, 2.4% (p = 0.86).

CONCLUSION

ACL reconstruction with ultrasound-guided FNB does not affect knee extensor strength at 6 months, nor graft rupture at 1 year postoperatively.

Femoral nerve versus adductor canal block for early postoperative pain control and knee function after anterior cruciate ligament reconstruction with hamstring autografts: a prospective single-blind randomised controlled trial

INTRODUCTION

The optimal pain management strategy for postoperative pain after anterior cruciate ligament reconstruction (ACLR) remains unclear. This study compared femoral nerve block (FNB) and adductor canal block (ACB) for pain management of early postoperative pain, knee function, and recovery of activity of daily living (ADL) after ACLR using hamstring autografts.

MATERIAL AND METHODS

In this prospective, single-blind, randomised controlled trial, 64 patients aged 12-56 years who underwent anatomical double-bundle ACLR with a hamstring autograft between August 2019 and May 2020 were randomised to undergo preoperative FNB (n = 32) or ACB (n = 32). The peripheral nerve block was performed by a single experienced anaesthesiologist under ultrasound guidance. The primary outcomes were postoperative pain as evaluated using the visual analogue scale (VAS) at 3, 6, 12, 24, and 48 h postoperatively and the need for pain relief. The secondary outcome was knee function, including the recovery of range of motion, contraction of the vastus medialis, and stable walking with a double-crutch (ADL), as evaluated by blinded physical therapists.

RESULTS

There were no significant differences in patient demographics between the two groups. The VAS scores, need for pain relief, knee function, and ADL did not significantly differ between the groups.

CONCLUSION

FNB and ACB provided comparable outcomes related to early postoperative pain, knee function, and ADL after double-bundle ACLR using hamstring autografts. Further research is necessary to evaluate the mid- to long-term effect of each block on recovery of knee function and ADL.

LEVEL OF EVIDENCE

I.