Adductor Canal Nerve Versus Femoral Nerve Blockade for Pain Control and Quadriceps Function Following Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft: A Prospective Randomized Trial

Does Proximal Adductor Canal Block Provide Better Analgesic Efficacy than Distal Adductor Canal Block in Patients Undergoing Knee Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

To compare the analgesic efficacy and adverse events of proximal versus distal ACB for adults undergoing knee arthroplasty, we searched PubMed, Cochrane, Web of Science, and Embase to identify all eligible randomized controlled trials (RCTs). The study quality of the RCTs was evaluated using the Cochrane risk of bias assessment tool. Heterogeneity among studies was examined by Cochrane Q test. Our primary outcomes were pain intensity at rest/during movement and morphine consumption. Statistical analyses were conducted by RevMan Software. Seven eligible studies involving 400 subjects were included in this meta-analysis with 202 participants in the proximal ACB group and 198 participants in the distal ACB group. The results demonstrated that proximal ACB provided significantly better pain relief at rest at 2 h (SMD -0.27, 95% CI -0.54 to -0.01, four trials, 222 participants, I2 = 0, p = 0.04) and 24 h (SMD -0.28, 95% CI -0.48 to -0.08, seven trials, 400 participants, I2 = 0, p = 0.006) following the surgery. We found no evidence of a difference in postoperative pain intensity at other timepoints. Furthermore, we noted no evidence of a difference in cumulative morphine consumption and occurrence of adverse events. Proximal ACB provides better pain relief and comparable adverse effects profile compared with distal ACB. The analgesic benefit offered by proximal ACB, however, did not appear to extend beyond the first 24 h. The overall evidence level was mostly low or very low, which requires more well-organized multicenter randomized trials in the future.

Multisite prospective study of perioperative pain management practices for anterior cruciate ligament reconstruction in adolescents: Society for Pediatric Anesthesia Improvement Network (SPAIN) Project Report

INTRODUCTION

Although 200 000 adolescents undergo anterior cruciate ligament reconstruction (ACLR) surgery annually, no benchmarks for pediatric post-ACLR pain management exist. We created a multicenter, prospective, observational registry to describe pain practices, pain, and functional recovery after pediatric ACLR.

METHODS

Participants (n=519; 12-17.5 years) were enrolled from 15 sites over 2 years. Data on perioperative management and surgical factors were collected. Pain/opioid use and Lysholm scores were assessed preoperatively, on postoperative day 1 (POD1), POD3, week 6, and month 6. Descriptive statistics and trends for opioid use, pain, and function are presented.

RESULTS

Regional analgesia was performed in 447/519 (86%) subjects; of these, adductor canal single shot was most frequent (54%), nerve catheters placed in 24%, and perineural adjuvants used in 43%. On POD1, POD3, week 6, and month 6, survey response rates were 73%, 71%, 61%, and 45%, respectively. Over these respective time points, pain score >3/10 was reported by 64% (95% CI: 59% to 69%), 46% (95% CI: 41% to 52%), 5% (95% CI: 3% to 8%), and 3% (95% CI: 1% to 6%); the number of daily oxycodone doses used was 2.8 (SD 0.19), 1.8 (SD 0.13), 0, and 0. There was considerable variability in timing and tests for postdischarge functional assessments. Numbness and weakness were reported by 11% and 4% at week 6 (n=315) and 16% and 2% at month 6 (n=233), respectively.

CONCLUSION

We found substantial variability in the use of blocks to manage post-ACLR pain in children, with a small percentage experiencing long-term pain and neurological symptoms. Studies are needed to determine best practices for regional anesthesia and functional assessments in this patient population.

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.

Adductor Canal Nerve Block versus Intra-articular Anesthetic in Knee Arthroscopy: A Single-Blinded Prospective Randomized Trial

Effective perioperative pain control following knee arthroscopy allows patients to reduce narcotic intake, avoid side effects of these medications, and recover more quickly. Adductor canal nerve blockade (ACB) and intra-articular injection of local anesthetic have been described as adjuvant treatments for postoperative pain control following surgery of the knee. This study directly compares the effect of each of these treatment modalities. Patients undergoing knee arthroscopy were blinded and randomized to receive either an ACB (n = 60) or intra-articular injection of local anesthetic (IAB, n = 64). Outcome measures included patient reported visual analog scale (VAS) scores at 1, 2, 4, 8, 16, 24, 36, 48 hours and 1 week and total narcotic consumption at 12, 24, and 48 hours postoperatively. Student's t-tests were used to compare unadjusted VAS scores at each time point and use of postoperative pain medication between treatment groups. Adjusted VAS scores were estimated in a multivariable general linear model with interaction of time and treatment group and other relevant covariates. There were no statistically significant differences between the two groups in terms of gender, age, body mass index, and insurance type. ACB patients had significantly higher pain scores than IAB patients at hours 1 and 2 (hour 1: 4.02 [2.99] vs. 2.59 [3.00], p = 0.009; hour 2: 3.12 [2.44] vs. 2.17 [2.62], p = 0.040). ACB patients had higher pain scores than IAB patients up to hour 16, though hours 4 to 16 were not significantly different. Adjusted covariate analyses demonstrate an additional statistically significant reduction in pain score in the IAB group at hour 4. There were no differences in narcotic consumption. Intraoperative local anesthetic and regional ACB each provides adequate pain control following knee arthroscopy, and intraoperative local anesthetic may provide enhanced pain control for up to 4 hours postoperatively. LEVEL OF EVIDENCE: : Level 1 evidence, randomized control trial.

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.

The Effectiveness of Adductor Canal Block Compared to Femoral Nerve Block on Readiness for Discharge in Patients Undergoing Outpatient Anterior Cruciate Ligament Reconstruction: A Multi-Center Randomized Clinical Trial

This study evaluated the effect of adductor canal block (ACB) versus femoral nerve block (FNB) on readiness for discharge in patients undergoing outpatient anterior cruciate ligament (ACL) reconstruction. We hypothesized that ACB would provide sufficient pain relief while maintaining motor strength and safety, thus allowing for earlier discharge. This was a randomized, multi-center, superiority trial. From March 2014 to July 2017, patients undergoing ACL reconstruction were enrolled. The primary outcome was the difference in readiness for discharge, defined as Post-Anesthetic Discharge Scoring System score ≥ 9. Twenty-six patients were allocated to FNB and twenty-seven to ACB. No difference in readiness for discharge was found (FNB median 1.8 (95% CI 1.0 to 3.5) vs. ACB 2.9 (1.5 to 4.7) hours, p = 0.3). Motor blocks and (near) falls were more frequently reported in patients with FNB vs. ACB (20 (76.9%) vs. 1 (3.7%), p < 0.001, and 7 (29.2%) vs. 1 (4.0%), p = 0.023. However, less opioids were consumed in the post-anesthesia care unit for FNB (median 3 [0, 21] vs. 15 [12, 42.5] oral morphine milligram equivalents, p = 0.004) for ACB. Between patients with FNB or ACB, no difference concerning readiness for discharge was found. Despite a slight reduction in opioid consumption immediately after surgery, FNB demonstrates a less favorable safety profile compared to ACB, with more motor blocks and (near) falls.

Ultrasound-Guided Genicular Nerve Blocks for Anterior Cruciate Ligament Reconstruction Surgery in an Outpatient Setting: A Case Series

Arthroscopic knee anterior cruciate ligament (ACL) reconstruction is commonly performed as an outpatient surgery, where adequate pain control and early ambulation play key roles in recovery and discharge. Peripheral nerve blocks aid in this purpose. Blockade of the genicular nerves, the articular branches of the knee, has recently become popular for knee surgery. We report on four patients who underwent ACL reconstruction with ultrasound-guided genicular nerve blocks (GNBs) under general anesthesia. The blocks were reliably performed without any complications, and the patients experienced good pain control, reduced opioid intake, and timely discharge following the surgery. These findings necessitate future investigations into the use of GNBs in ACL reconstruction.

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.

Femoral Nerve Block and Local Instillation Analgesia Associated With More Reliable Efficacy in Regional Anesthesia Interventions Within 24 Hours Following Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis

PURPOSE

To assess the relative effectiveness of different regional anesthetic techniques (peripheral nerve blocks, local instillation analgesia, including intra-articular, subcutaneous, and periarticular infiltration) in patients undergoing anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched from their inception to December 31, 2020. The search was supplemented by manual review of relevant reference lists. Randomized controlled trials of participants after ACLR that compared regional anesthesia interventions were selected. The 2 coprimary outcomes were (1) rest pain scores and (2) cumulative oral morphine equivalent consumption on day 1 (24 hours) post-ACLR. Data were pooled using a Bayesian framework.

RESULTS

Of 759 records identified, 46 trials were eligible, evaluating 9 interventions in 3,171 patients. Local instillation analgesia (LIA), including intra-articular, subcutaneous, and periarticular infiltration, had significant improvement in pain relief as compared with placebo (-0.91; 95% CrI -1.45 to -0.37). Femoral nerve block (FNB) also showed significant effects in relieving pain as compared with placebo (-0.70; 95% 95% credible interval [CrI] -1.28 to -0.12). Compared with placebo, a significant reduction in opioid consumption was found in LIA (mean difference -13.29 mg; 95% CrI -21.77 to -4.91) and FNB (mean difference -13.97 mg; 95% CrI -24.71 to -3.04). Femoral and sciatic nerve block showed the greatest ranking for pain relief and opioid consumption without significant evidence (P > .05) to support superiority in comparison with placebo, respectively.

CONCLUSIONS

Our meta-analysis shows that FNB and LIA can significantly diminish postoperative pain and reduce opioid consumption following ACLR compared with placebo in the setting of regional anesthesia, and femoral and sciatic nerve block may be the number 1 top-ranked analgesic technique despite high uncertainty.

LEVEL OF EVIDENCE

I, Systematic review of Level I studies.

Network meta-analysis of the analgesic effectiveness of regional anaesthesia techniques for anterior cruciate ligament reconstruction

Anterior cruciate ligament reconstruction can cause moderate to severe acute postoperative pain. Despite advances in our understanding of knee innervation, consensus regarding the most effective regional anaesthesia techniques for this surgical population is lacking. This network meta-analysis compared effectiveness of regional anaesthesia techniques used to provide analgesia for anterior cruciate ligament reconstruction. Randomised trials examining regional anaesthesia techniques for analgesia following anterior cruciate ligament reconstruction were sought. The primary outcome was opioid consumption during the first 24 h postoperatively. Secondary outcomes were: rest pain at 0, 6, 12 and 24 h; area under the curve of pain over 24 h; and opioid-related adverse effects and functional recovery. Network meta-analysis was conducted using a frequentist approach. A total of 57 trials (4069 patients) investigating femoral nerve block, sciatic nerve block, adductor canal block, local anaesthetic infiltration, graft-donor site infiltration and systemic analgesia alone (control) were included. For opioid consumption, all regional anaesthesia techniques were superior to systemic analgesia alone, but differences between regional techniques were not significant. Single-injection femoral nerve block combined with sciatic nerve block had the highest p value probability for reducing postoperative opioid consumption and area under the curve for pain severity over 24 h (78% and 90%, respectively). Continuous femoral nerve block had the highest probability (87%) of reducing opioid-related adverse effects, while local infiltration analgesia had the highest probability (88%) of optimising functional recovery. In contrast, systemic analgesia, local infiltration analgesia and adductor canal block were each poor performers across all analgesic outcomes. Regional anaesthesia techniques that target both the femoral and sciatic nerve distributions, namely a combination of single-injection nerve blocks, provide the most consistent analgesic benefits for anterior cruciate ligament reconstruction compared with all other techniques but will most likely impair postoperative function. Importantly, adductor canal block, local infiltration analgesia and systemic analgesia alone each perform poorly for acute pain management following anterior cruciate ligament reconstruction.

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.

Perioperative Gabapentin May Reduce Opioid Requirement for Early Postoperative Pain in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials

PURPOSE

To evaluate the efficacy of perioperative gabapentin or pregabalin treatment on postoperative pain and opioid requirement reduction in patients undergoing anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic review of randomized control trials was conducted evaluating the effect of gabapentin or pregabalin on postoperative pain and opioid requirement for patients undergoing ACLR. The primary outcomes assessed were postoperative pain scores and opioid requirements. Secondary outcomes were complications, side effects, dosage, and timing of intervention.

RESULTS

The initial search query identified 151 studies and 6 studies were included after full-text articles were reviewed. Three studies investigated the use of gabapentin and three studies investigated pregabalin. All three gabapentin studies reported significantly decreased or equivalent pain scores while also significantly reducing or removing total opioid consumption compared to control groups. Pregabalin demonstrated inconsistent efficacy for pain control and opioid consumption parameters across three studies. One study (pregabalin, n = 1) reported significantly increased incidence of dizziness with pregabalin compared to placebo.

CONCLUSION

There is moderate evidence demonstrating that preoperative gabapentin may be safe and effective in reducing postoperative pain and opioid consumption after ACLR. Gabapentin may be considered when employed as part of a multimodal analgesia regimen; however, the optimal protocol has yet to be determined. Currently, there is limited evidence demonstrating the efficacy of pregabalin on pain and opioid consumption in the setting of ACLR.

LEVEL OF EVIDENCE

Systematic Review of Level I Studies.

Comparison of adductor canal block and femoral nerve block for pain management in anterior cruciate ligament reconstruction: A meta-analysis of randomized controlled trials

OBJECTIVE

To compare the efficacy of adductor canal block and femoral nerve block for pain management in patients with anterior cruciate ligament reconstruction.

METHODS

A computerized search was performed in the database of PubMed, Embase, Web of Science and Cochrane Library for randomized controlled trials. The outcome measures included visual analog scale, morphine consumption, quadriceps strength, length of hospitalization and postoperative adverse events. The risk of bias of randomized controlled trials was assessed according to the Cochrane Risk of Bias Tool. All quantitative syntheses were completed using STATA version 14.

RESULTS

Seven randomized controlled trials involving a total of 643 patients were included in our meta-analysis. The present meta-analysis indicated that there were no significant differences between the 2 groups in terms of postoperative pain score, opioid consumption, length of hospitalization or adverse effects after anterior cruciate ligament reconstruction. However, adductor canal block showed superior quadriceps strength and range of motion in the early postoperative period.

CONCLUSION

Adductor canal block shows similar and adequate analgesia compared to the femoral nerve block in anterior cruciate ligament reconstruction and adductor canal block can preserve a higher quadriceps strength and better range of motion.

Peripheral Nerve Blockade for Medial Patellofemoral Ligament Reconstruction in Pediatric Patients: The Addition of a Proximal Single-Injection Sciatic Nerve Block Provides Improved Analgesia

Purpose

We tested the hypothesis that the addition of a single-injection proximal sciatic nerve block to an adductor canal block would significantly reduce pain scores and opioid requirements compared to a group of patients that received only an adductor canal or femoral nerve block for medial patellofemoral ligament reconstruction in pediatric patients. The primary end-point is the number of patients achieving a Patient Acceptable Symptom State (PASS) (pain score less than four) for the entire 24-hour postoperative period in patients with and without a proximal sciatic block.

Patients and Methods

This is a retrospective cohort study of 144 consecutive pediatric patients, ages 10 to 18 years, undergoing medial patellofemoral ligament reconstruction with peripheral nerve blockade for postoperative analgesia from 2016–2020 at a pediatric orthopedics children’s hospital. Patients were divided into 2 cohorts with and without a proximal sciatic nerve block: group A/F: adductor canal or femoral CPNB and group AS: adductor canal CPNB and a proximal single-injection sciatic nerve block.

Results

There was strong evidence for an increase in the number of patients who reported a pain score less than four for the entire 24-hour postoperative period in the group that received the additional proximal sciatic block. (PASS: A/F 13/62 (21%) vs AS 43/82 (52%), p<0.001) There was strong evidence for a reduction in mean and maximum pain scores and opioid requirements in the first 24-hours after surgery in the proximal sciatic group.

Conclusion

The addition of a proximal sciatic nerve block was associated with significantly reduced mean and maximum pain scores and opioid requirements after medial patellofemoral ligament reconstruction in pediatric patients and supports a randomized clinical trial to confirm these findings. Based on the results of this study we recommend the addition of a proximal sciatic nerve block, anterior or posterior, to an adductor canal block to provide improved analgesia and reduced opioid requirements in the 24-hours after MPFLR in pediatric patients.

Comparative Study of Adductor Canal Block and Femoral Nerve Block for Postoperative Analgesia After Arthroscopic Anterior Cruciate Ligament Tear Repair Surgeries

Objective: The study aimed to compare an adductor canal block (ACB) with a femoral nerve block (FNB) with regard to their analgesic efficacy and the quadriceps muscle strength in patients following arthroscopic anterior cruciate ligament (ACL) tear repair surgeries.

Materials and Methods: Ninety patients in the American Society of Anaesthesiologists (ASA) status I or II undergoing arthroscopic ACL tear repair surgeries under subarachnoid block were divided into three groups to receive ACB (Group ACB), FNB (Group FNB), and control (Group C). Each patient was assessed for Visual Analogue Scale (VAS) score, tramadol consumption, and quadriceps muscle strength postoperatively in the post anaesthesia care unit (PACU).

Results: There was no significant difference between the Group ACB and Group FNB regarding postoperative analgesia and total rescue analgesic consumption at 24 hrs postoperative. The mean VAS score at two, four, and six hours and total rescue analgesic consumption in 24 hrs were higher in the control group, which was statistically significant (p-value <0.05). Quadriceps muscle strength by straight leg raise test was significantly higher in the Group ACB compared with the Group FNB at 0, 6, 12, 18 hours postoperatively (p-value <0.0001), whereas the difference between both study groups become statistically insignificant at 24 hours postoperative.

Conclusion: ACB preserved quadriceps muscle strength better than FNB, without a significant difference in postoperative analgesia after arthroscopic ACL tear repair surgeries.

Most Analgesia Treatments Have No Clinical Significance for Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis of 66 Randomized Controlled Trials

PURPOSE

To assess the relative efficacy of several clinical treatments for postoperative analgesia of anterior cruciate ligament reconstruction through network meta-analysis based on multiple published randomized controlled trials.

METHODS

We searched PubMed, the Cochrane library, EMBASE, and Web of Science, each from inception until February 15, 2021. Outcomes including pain scores at rest (visual analog scale, numerical rating scales, and other scales, which were converted to a standardized 0-10 scale), morphine consumption, and complications were meta-analyzed. Quality of the included studies was assessed using the Cochrane risk-of-bias tool. The authors defined the best choice for postoperative analgesia as the one that had significant difference in pain scores, morphine consumption, and had no significant difference in the risk of complications compared with placebo in the initial 48 postoperative hours.

RESULTS

In total, 66 studies with 4,168 patients were included in this network meta-analysis. Only periarticular infiltration was significantly superior to placebo in pain scores and morphine consumption (pain at 2 hours: mean difference [MD] -0.74, 95% confidence interval [CI] -1.36 to -0.12; pain at 6 hours: MD -0.81, 95% CI -1.42 to -0.21; pain at 12 hours: MD -0.85, 95% CI -1.53 to -0.17; pain at 24 hours: MD -0.80, 95% CI -1.19 to -0.40; morphine consumption at 24 hours: MD -10.12, 95% CI -14.31 to -5.93; morphine consumption at 48 hours: MD -5.62, 95% CI -6.74 to -4.51). Periarticular infiltration did not increase the risk of complications compared with placebo (nausea and vomiting: odds ratio [OR] 0.63, 95% CI 0.34-1.16; pruritus: OR 0.74, 95% CI 0.35-1.58; urinary retention: OR 0.55, 95% CI 0.25-1.23). In addition, There was no significant difference between adductor canal block and femoral nerve block in pain scores and morphine consumption (pain at 2 hours: MD -0.01, 95% CI -1.44 to 1.42; pain at 6 hours: MD 0.29, 95% CI -0.28 to 0.86; pain at 12 hours: MD 0.36, 95% CI -0.44 to 1.16; pain at 24 hours: MD 0.26, 95% CI -0.22 to 0.75; pain at 48 hours: MD -0.36, 95% CI -0.97 to 0.24; morphine at 24 hours: MD 1.04, 95% CI -4.70 to 6.79; morphine at 48 hours: MD -0.32, 95% CI -0.70 to 0.07; postoperative nausea and vomiting: OR 1.07, 95% CI 0.55-2.09; pruritus: OR 1.36, 95% CI 0.66-2.79; urinary retention: OR 1.41, 95% CI 0.37-5.29).

CONCLUSIONS

Based on current evidence, most analgesic methods could result in lower pain scores and decrease morphine consumption when compared with placebo; however, differences between methods were small and inconsistent. There seemed to be no significant difference between adductor canal block and femoral nerve block in pain score, morphine consumption and complications.

LEVEL OF EVIDENCE

Level I, meta-analysis of Level I RCTs.

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.

Overprescribing and Undereducating: a Survey of Pre- and Postoperative Pain Protocols for Pediatric Anterior Cruciate Ligament Surgery

Purpose

To establish a better understanding of the variations in pain management protocols and prescribing patterns for pediatric patients undergoing anterior cruciate ligament (ACL) reconstruction or repair.

Methods

A 20-question multiple-choice survey was distributed to 3 professional orthopaedic societies to assess the pre-emptive and postoperative pain management prescribing patterns for pediatric patients undergoing ACL reconstruction or repair. Clinical agreement (defined as agreement between >80% of participants) and general agreement (defined as agreement between >60% of participants) were calculated based on responses as previously reported.

Results

Clinical agreement was observed among the 68 respondents in use of a single shot nerve block before induction of anesthesia versus continuous use when a peripheral nerve block was used, “always” counseling patients on postoperative pain control, the prescribing of opioids postoperatively, and a lack of change in postoperative protocol when concomitant meniscal repair or meniscectomy was performed. General agreement was observed in the use of a peripheral nerve block, some pre-emptive analgesia practices, and the lack of counseling patients with regard to disposal of unused opioid pain medication postoperatively. Opioids were prescribed by 88% of participants postoperatively, with 48% prescribing 11 to 19 pills and 15% prescribing ≥20 pills.

Conclusions

While pain management practices before and following ACL reconstruction and repair in the pediatric population remain varied, opioids are frequently prescribed postoperatively with many providers neglecting to provide instruction on excess opioid disposal.

Clinical Relevance

ACL reconstruction and repair is becoming increasingly common in the pediatric population. Clinical guidelines that establish pre-emptive and postoperative pain-control protocols should be considered to determine safe and optimal pain control throughout the duration of care while minimizing opioid prescribing and consumption.

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.

Managing Perioperative Pain After Anterior Cruciate Ligament (ACL) Reconstruction: Perspectives from a Sports Medicine Surgeon

Anterior cruciate ligament reconstructions (ACLR) are a relatively common procedure in orthopedic sports medicine with an estimated 130,000 arthroscopic operations performed annually. Most procedures are carried out on an outpatient basis, and though success rates of ACLR are as high as 95%, pain remains the most common postoperative complication delaying patient discharge, and thereby increasing the costs associated with patient care. Despite the success and relative frequency of ACLR surgery, optimal and widely accepted strategies and regimens for controlling perioperative pain are not well established. In recent years, the paradigm of pain control has shifted from exclusively utilizing opiates and opioid medications in the acute postoperative period to employing other agents and techniques including nerve blocks, intra-articular and periarticular injections of local anesthetic agents, NSAIDs, and less commonly, ketamine, tranexamic acid (TXA), sedatives, gabapentin, and corticosteroids. More often, these agents are now used in combination and in synergy with one another as part of a multimodal approach to pain management in ACLR, with the goal of reducing postoperative pain, opioid consumption, and the incidence of delayed hospital discharge. The purpose of this review is to consolidate current literature on various agents involved in the management of postoperative pain following ACLR, including the role of classically used opiate and opioid medications, as well as to describe other drugs currently utilized in practice either individually or in conjunction with other agents as part of a multimodal regimen in pain management in ACLR.

Contribution of Multimodal Analgesia to Postoperative Pain Outcomes Immediately After Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Level 1 Randomized Clinical Trials

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is associated with moderate to severe pain in the immediate postoperative period. The optimal individual preemptive or intraoperative anesthetic modality on postoperative pain control is not well-known.

PURPOSE

To systematically review and perform a meta-analysis comparing postoperative pain scores (visual analog scale [VAS]), opioid consumption, and incidence of complications during the first 24 hours after primary ACLR in patients receiving spinal anesthetic, adjunct regional nerve blocks, or local analgesics.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

PubMed, Embase, MEDLINE, Biosis Previews, SPORTDiscus, Ovid, PEDRO, and the Cochrane Library databases were systematically searched from inception to March 2020 for human studies, using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist. Inclusion criteria consisted of (1) level 1 studies reporting on the use of spinal anesthesia, adjunct regional anesthesia (femoral nerve block [FNB] or adductor canal block [ACB]), or local analgesia in patients undergoing primary ACLR and (2) studies reporting on patient-reported VAS, opioid consumption, and incidence of complications related to anesthesia within the first 24 hours after surgery. Non-level 1 studies, studies utilizing a combination of anesthetic modalities, and those not reporting outcomes during the first 24 hours were excluded. Data were synthesized, and a random effects meta-analysis was performed to determine postoperative pain, opioid use, and complications based on anesthetic modality at multiple time points (0-4, 4-8, 8-12, 12-24 hours).

RESULTS

A total of 263 studies were screened, of which 27 level 1 studies (n = 16 regional blocks; n = 12 local; n = 4 spinal) met the inclusion criteria and were included in the meta-analysis. VAS scores were significantly lower in patients receiving a regional block as compared with spinal anesthesia 8 to 12 hours after surgery (P < .01), patients receiving an FNB versus ACB at 12 to 24 hours (P < .01), and those treated with a continuous FNB rather than single-shot regional blocks (FNB, ACB) at 12 to 24 hours (P < .01). No significant difference in VAS was appreciated when spinal, regional, and local anesthesia groups were compared.

CONCLUSION

Based on evidence from level 1 studies, pain control after primary ACLR based on VAS was significantly improved at 8 to 12 hours in patients receiving regional anesthesia as compared with spinal anesthesia. Pain scores were significantly lower at 12 to 24 hours in patients receiving FNB versus ACB and those treated with continuous FNB rather than single-shot regional anesthetic.

Quadriceps and Hamstring Strength in Adolescents 6 Months After ACL Reconstruction With Femoral Nerve Block, Adductor Canal Block, or No Nerve Block

Background:

Femoral nerve block (FNB) and adductor canal block (ACB) have been used increasingly for pain control during anterior cruciate ligament (ACL) reconstruction in adolescent patients. However, recent evidence suggests that the use of FNB may affect quadriceps strength recovery 6 months after surgery.

Purpose/Hypothesis:

To compare postoperative isokinetic strength in adolescents who received FNB, ACB, or no block for perioperative analgesia during ACL reconstruction. We anticipated lower postoperative quadriceps and hamstring isokinetic deficits in adolescents who received FNB as compared with ACB.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients were included in the study if they had undergone hamstring tendon autograft ACL reconstruction by a single surgeon from July 2008 to January 2018 and if they underwent isokinetic muscle testing at 4 to 8 months postoperatively. The participants were divided into 3 groups (no block, FNB, and ACB), and we compared the deficit in percentages between the affected and unaffected limbs as calculated from the isokinetic quadriceps and hamstring strength testing at 60 and 180 deg/s. Between-group analysis was performed using analysis of variance, with an alpha of .05.

Results:

A total of 98 participants were included in the analysis (31 no block, 36 FNB, and 31 ACB). The mean ± SD age of the patients was 15.26 ± 1.15, 15.50 ± 1.42, and 15.71 ± 1.44, for no block, FNB, and ACB, respectively. At 5.61 months postoperatively, there was no significant difference across the 3 groups in isokinetic quadriceps deficits (P ≥ .99), and the only significant difference in isokinetic hamstring deficit was observed for peak flexion at 180 deg/s, in which the ACB group had lower peak torque than the FNB group (–9.80% ± 3.48% vs 2.37% ± 3.23%; P = .035). The ratio of participants with a deficit exceeding 15% did not differ significantly among the 3 groups.

Conclusion:

Contrary to previous research, our findings indicate only minimal difference in quadriceps strength among the 3 types of perioperative analgesia in adolescents approximately 6 months after ACL reconstruction. The only significant strength deficit was seen in the hamstrings of patients receiving ACB at peak flexion as compared with those receiving FNB.

Rupture, reconstruction, and rehabilitation: A multi-disciplinary review of mechanisms for central nervous system adaptations following anterior cruciate ligament injury

BACKGROUND

Despite surgical reconstruction and extensive rehabilitation, persistent quadriceps inhibition, gait asymmetry, and functional impairment remain prevalent in patients after anterior cruciate ligament (ACL) injury. A combination of reports have suggested underlying central nervous system adaptations in those after injury govern long-term neuromuscular impairments. The classic assumption has been to attribute neurophysiologic deficits to components of injury, but other factors across the continuum of care (e.g. surgery, perioperative analgesia, and rehabilitative strategies) have been largely overlooked.

OBJECTIVE

This review provides a multidisciplinary perspective to 1) provide a narrative review of studies reporting neuroplasticity following ACL injury in order to inform clinicians of the current state of literature and 2) provide a mechanistic framework of neurophysiologic deficits with potential clinical implications across all phases of injury and recovery (injury, surgery, and rehabilitation) RESULTS: Studies using a variety of neurophysiologic modalities have demonstrated peripheral and central nervous system adaptations in those with prior ACL injury. Longitudinal investigations suggest neurophysiologic changes at spinal-reflexive and corticospinal pathways follow a unique timecourse across injury, surgery, and rehabilitation.

CONCLUSION

Clinicians should consider the unique injury, surgery, anesthesia, and rehabilitation on central nervous system adaptations. Therapeutic strategies across the continuum of care may be beneficial to mitigate maladaptive neuroplasticity in those after ACL injury.

Pain Management Strategies After Anterior Cruciate Ligament Reconstruction: A Systematic Review With Network Meta-analysis

PURPOSE

To systematically review randomized controlled trials (RCTs) evaluating various pain control interventions after anterior cruciate ligament reconstruction (ACLR) to determine the best-available evidence in managing postoperative pain and to optimize patient outcomes.

METHODS

A systematic review of the literature was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. A study was included if it was an RCT evaluating an intervention to reduce postoperative pain acutely after ACLR in one of the following areas: (1) nerve blocks, (2) nerve block adjuncts, (3) intra-articular injections, (4) oral medications, (5) intravenous medications, (6) tranexamic acid, and (7) compressive stockings and cryotherapy. Quantitative and qualitative statistics were carried out, and network meta-analysis was performed where applicable.

RESULTS

Overall, 74 RCTs were included. Across 34 studies, nerve blocks were found to significantly reduce postoperative pain and opioid use, but there was no significant difference among the various nerve blocks in the network meta-analysis. Intra-articular injections consisting of bupivacaine and an adjunct were found to reduce reported postoperative pain scores up to 12 hours after ACLR, with significantly lower postoperative opioid use.

CONCLUSIONS

Nerve blocks and regional anesthesia are the mainstay treatment of postoperative pain after ACLR, with the commonly used nerve blocks being equally efficacious. Intra-articular injections consisting of bupivacaine and an adjunct were found to reduce reported postoperative pain scores up to 12 hours after ACLR, with significantly lower postoperative opioid use. There was promising evidence for the use of some oral and intravenous medications, tranexamic acid, and nerve block adjuncts, as well as cryotherapy, to control pain and reduce postoperative opioid use.

LEVEL OF EVIDENCE

Level II, systematic review and meta-analysis of RCTs.

Anterior cruciate ligament reconstruction with the use of adductor canal block can achieve similar pain control as femoral nerve block

PURPOSE

Moderate-to-severe postoperative pain remains a challenge for both patients and surgeons after anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to systematically review the current evidence in the literature to compare adductor canal block (ACB) with femoral nerve block (FNB) in the treatment of ACLR.

METHODS

A comprehensive search of the published literature in PubMed, Scopus, EMBASE, and Cochrane Library databases was performed. Only English randomized clinical trials (RCTs) were included in this study. The primary outcome was pain score. Secondary outcome measures included opioid consumption, postoperative adverse events, patient satisfaction, and quadriceps strength.

RESULTS

Eight RCTs with a total of 587 patients were included. No statistically significant difference was observed between the ACB and FNB groups in pain scores at 6 h, 12 h, 24 h, or 48 h; cumulative opioid consumption at 24 h or 48 h; patient satisfaction at 24 or 48 h; and postoperative adverse event. However, ACB showed superior quadriceps strength in the early postoperative period.

CONCLUSIONS

Both treatments provided similar overall pain relief after ACLR. The potential benefits of quadriceps preservation with ACB are worthy of future study. Therefore, ACB is recommended as an attractive alternative to FNB as the peripheral nerve block of choice for ACLR.

LEVEL OF EVIDENCE

Meta-analysis of Level 1 was performed in this study.

Effect of Adductor Canal Block Versus Femoral Nerve Block on Quadriceps Strength, Function, and Postoperative Pain After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Level 1 Studies

BACKGROUND

Femoral nerve block (FNB) is a popular technique for reducing postoperative pain in patients with anterior cruciate ligament reconstruction (ACLR), but it is also linked to a number of adverse effects, such as quadriceps weakness, antalgic ambulation, and increased fall risk. Adductor canal block (ACB) has been offered as a motor nerve-sparing alternative to FNB.

PURPOSE

To evaluate available literature that compares the effects of ACB and FNB on functional outcomes after arthroscopic ACLR.

STUDY DESIGN

Systematic review.

METHODS

Following the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a search of PubMed (Ovid), CINAHL, Scopus, Cochrane, and Google Scholar databases was conducted. Search terms were designed to capture studies comparing the effects of ACB and FNB in patients undergoing arthroscopic ACLR. Data were evaluated regarding study and patient characteristics, functional measures, opioid consumption, pain scores, and complications.

RESULTS

Eight randomized controlled trials (N = 655 patients) comparing the efficacy of ACB versus FNB in arthroscopic ACLR were included. The heterogeneity of outcome measures precluded meta-analysis. Seven studies reported functional measures, which included isokinetic strength, straight-leg raise, and other various measures. Follow-up periods varied between 1 hour and 6 months. In 3 trials, ACB was found to preserve quadriceps strength as measured using straight-leg raise for the first 12 to 24 hours after surgery, while 3 other trials found no difference between the groups. No differences were reported in isokinetic strength at 6 months. In other functional measures, ACB either outperformed or was equivalent to FNB. The majority of studies reporting opioid consumption, pain scores, and complications found no differences between the blocks.

CONCLUSION

This systematic review suggests that when compared with FNB, ACB preserves quadriceps function in the early postoperative period after ACLR while providing a similar level of analgesia. Limitations of this study include the use of various functional measures and limited long-term follow-up. More research evaluating long-term functional outcomes with standardized measures is needed to draw adequate conclusions regarding the effects of ACB and FNB on function after ACLR.

Adductor Canal Versus Femoral Nerve Block after Anterior Cruciate Ligament Reconstruction: A Systematic Review of Level I Randomized Controlled Trials Comparing Early Postoperative Pain, Opioid Requirements, and Quadriceps Strength

PURPOSE

To systematically review the literature to compare the adductor canal block (ACB) with the femoral nerve block (FNB) following primary anterior cruciate ligament reconstruction (ACLR) in terms of early postoperative analgesic requirements and postoperative quadriceps strength.

METHODS

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase up to August 2019 to identify randomized controlled trials that compared postoperative pain and functional outcomes in patients following primary ACLR with ACB versus FNB. The search phrase used was: adductor canal femoral nerve anterior cruciate ligament. Patients were evaluated based on analgesic consumption and quadriceps muscle strength. Study quality and risk of bias were evaluated with the Modified Coleman Methodology Score and Cochrane risk-of-bias tool respectively.

RESULTS

Five studies (all Level I evidence) were identified that met inclusion criteria, including 221 patients undergoing primary ACLR with ACB (mean age 26.8 years, 68.3% male) and 221 with FNB (mean age 28.2 years, 67.0% male). Statistical assessment for heterogeneity found for opioid consumption of ACB versus FNB groups was I² = 97% (P < .0001). There were no significant differences in analgesic consumption within the first 24 hours following surgery between groups except in 1 study, in which patients receiving ACB required significantly greater analgesics (P < .001). Three studies using 3 different techniques to measure strength found patients receiving ACB to have significantly greater quadriceps muscle function within 24 hours of surgery when compared with patients receiving FNB (P < .05).

CONCLUSIONS

In patients undergoing ACLR, the ACB may provide similar analgesic requirements, and the included studies suggest a potential advantage in preserving muscle strength at short-term (24-48 hours) follow-up when compared with FNB. However, the differences in muscle strength assessments between studies do not allow for strong conclusions.

LEVEL OF EVIDENCE

I, systematic review and meta-analysis of Level I studies.

Perioperative and Postoperative Factors Influence Quadriceps Atrophy and Strength After ACL Reconstruction: A Systematic Review

Background:

Quadriceps dysfunction after anterior cruciate ligament (ACL) reconstruction is common and may affect return to sport due to resulting muscle atrophy and muscle weakness.

Purpose:

To systematically review the available literature regarding the impact of perioperative and postoperative interventions on quadriceps atrophy and loss of strength after ACL reconstruction.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was performed in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, CINAHL, Cochrane Central, and Embase. The quality of evidence was evaluated using the Modified Coleman Methodology Score to determine consensus scores. Eligible level 1 or level 2 studies included interventions of perioperative nerve block, intraoperative tourniquet use, postoperative nutritional supplementation, and postoperative blood flow restriction training. Additionally, the included studies quantified postoperative quadriceps measurements such as thigh circumference, quadriceps cross-sectional area (CSA), isokinetic quadriceps strength, and/or quadriceps electromyographic (EMG) testing.

Results:

In total, 15 studies met stated inclusion and exclusion criteria with the following intervention types: perioperative nerve block (n = 4), intraoperative tourniquet use (n = 5), postoperative nutritional supplementation (n = 3), and postoperative blood flow restriction (n = 3). Intraoperative tourniquet use resulted in decreased thigh circumference and detrimental EMG changes in quadriceps function in 3 of the 5 included studies. Perioperative femoral nerve blocks were associated with transient decreases in postoperative quadriceps strength, persisting up to 6 weeks after surgery, in 2 of the 4 studies. Postoperative blood flow restriction training augmented quadriceps size and function after ACL reconstruction in 2 of 3 studies. Postoperative nutritional supplementation was associated with increased quadriceps volume and strength in 1 of the 3 studies examined.

Conclusion:

The peri- and postoperative factors reviewed here may influence quadriceps atrophy and strength after ACL reconstruction. Our results tentatively indicated that blood flow restriction training may be beneficial to the quadriceps after ACL reconstruction and that intraoperative tourniquet use and nerve block administration may be detrimental; however, the strongest finding was that all of these interventions would benefit from further level 1 and 2 evidence studies, including multicenter, randomized controlled trials with extended follow-up, to definitively determine their impact on return to activity.

The Influence of Perioperative Nerve Block on Strength and Functional Return to Sports After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Patients often have quadriceps or hamstring weakness after anterior cruciate ligament reconstruction (ACLR), despite postoperative physical therapy regimens; however, little evidence exists connecting nerve blocks and ACLR outcomes.

PURPOSE

To compare muscle strength at return to play in patients who received a nerve block with ACLR and determine whether a specific block type affected subjective knee function.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were recruited 5 to 7 months after primary, isolated ACLR and completed bilateral isokinetic strength tests of the knee extensor/flexor groups as a single-session return-to-sport test. Subjective outcomes were assessed with the International Knee Documentation Committee (IKDC) score. Strength was expressed as torque normalized to mass (N·m/kg) and limb symmetry index as involved/uninvolved torque. Chart review was used to determine the type of nerve block and graft used. Nerve block types were classified as knee extensor motor (femoral nerve), knee flexor motor (sciatic nerve), or isolated sensory (adductor canal block/saphenous nerve). A 1-way analysis of covariance controlling for graft type was used.

RESULTS

A total of 169 patients were included. Graft type distribution consisted of 102 (60.4%) ipsilateral bone-patellar tendon-bone (BTB) and 67 (39.6%) ipsilateral hamstring tendon. Nerve block type distribution consisted of 38 (22.5%) femoral, 25 (14.8%) saphenous, 45 (26.6%) femoral and sciatic, and 61 (36.1%) saphenous and sciatic. No significant difference was found in knee extensor strength (P = .113) or symmetry (P = .860) between patients with knee extensor motor blocks (1.57 ± 0.45 N·m/kg; 70.1% ± 15.3%) and those without (1.47 ± 0.47 N·m/kg; 69.6% ± 18.8%). A significant difference was found between patients with knee flexor motor blocks (0.83 ± 0.26 N·m/kg) and those without (0.92 ± 0.27 N·m/kg) for normalized knee flexor strength (P = .21) but not knee flexor symmetry (P = .592). Controlling for graft type, there were no differences in subjective knee function (IKDC score) between all nerve block groups (P = .57).

CONCLUSION

Our data showed that use of a sciatic nerve block with ACLR in patients with hamstring and BTB grafts influences persistent knee flexor strength deficits at time of return to sports. Although the cause of postoperative muscular weakness is multifactorial, this study adds to the growing body of evidence suggesting that perioperative nerve blocks affect muscle strength and functional rehabilitation after ACLR.

Arthroscopy Annual Awards, a 35th Anniversary…and More

With sincere appreciation to the Arthroscopy Association of North America Education Foundation for their generous support, we announce our 2020 Annual Awards for the best Clinical Research, Basic Science Research, Resident/Fellow Research, and Systematic Reviews published in 2019, as well as the Most Downloaded and Most Cited papers published 5 years ago. Our January cover is a throwback in honor of the 35th anniversary of our journal, and our cover will sport a festive banner each month this year. We introduce our 2020 masthead and team, including a new Social Media Board. Finally, our Editor-in-chief, Assistant Editors, and Associate Editors update their disclosures of potential conflicts of interest.

Neurological structures and mediators of pain sensation in anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) tears is a devastating injury and one of the most common knee injuries experienced by athletes in the United States. Although patients reach maximal subjective improvement by one-year following ACL reconstruction, many patients often experience moderate to severe post-operative pain. Opioids, intra-articular injections, and regional anesthesia have been previously implemented to mediate post-operative pain. However, chronic opioid usage has become an epidemic in the United States. Alternative analgesic modalities, such as nerve blocks, have been implemented in clinical practice to provide adequate pain relief and minimize opioid usage. Periarticular injections targeted towards local neurological structures performed concomitantly with nerve blocks provides superior pain relief and satisfaction than isolated nerve blocks. Therefore, it is imperative for physicians to understand local neurological anatomy around the knee joint in order to provide adequate analgesia while minimizing opioid consumption. This purpose of this investigation is to summarize (1) neurogenic origins of pain generators and mediators in sites affected by ACL reconstruction and autograft harvest sites and (2) analgesia utilized in ACL reconstruction.