Adductor Canal Block Versus Femoral Nerve Block for Pain Control After Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Trial

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.

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.

Lower Opioid Prescription Quantity Does Not Negatively Impact Pain Control or Patient Satisfaction After ACL Reconstruction: A Randomized, Prospective Trial

BACKGROUND

The purpose of this study was to evaluate the effects of different quantities of prescribed opioid tablets on patient opioid utilization, postoperative pain and function, and satisfaction after anterior cruciate ligament reconstruction (ACLR).

METHODS

This was a prospective, randomized trial enrolling patients undergoing primary ACLR. Patients were assigned to 1 of 3 prescription groups: 15, 25, or 35 tablets containing 5-mg oxycodone. Patients completed visual analog scale (VAS) pain and medication logs, opioid medication satisfaction surveys, and International Knee Documentation Committee (IKDC) questionnaires postoperatively.

RESULTS

Among the 180 patients included in the analysis, there was no significant difference in VAS pain scores (p > 0.05), IKDC scores (p > 0.05), morphine milligram equivalents (MMEs) (p = 0.510) consumed, or patient satisfaction with regard to pain control (p = 0.376) between treatment groups. Seventy-two percent of opioids were consumed in the first 3 days postoperatively, and 83% of patients in the 15-tablet cohort felt that they received the "right amount" of or even "too many" opioids.

CONCLUSIONS

The prescription of 15 opioid tablets resulted in equivalent pain control, patient satisfaction, and short-term functional outcomes as prescriptions of 25 or 35 opioid tablets after ACLR. Lower prescription quantities of opioid medication may provide equivalent postoperative pain and help to minimize the number of unused opioid doses at risk for possible diversion after ACLR.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

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.

Does Liposomal Bupivacaine Injectable Suspension Peripheral Nerve Block Further Aid in Decreasing At-home Narcotic Utilization in Children and Adolescents After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Opioid misuse and addiction among children and adolescents is an increasingly concerning problem. This study sought to determine whether liposomal bupivacaine injectable suspension admixture administered as a single-shot adductor canal peripheral nerve block (SPNB+BL) would decrease utilization of at-home opioid analgesics after anterior cruciate ligament reconstruction (ACLR) in adolescents compared with single-shot peripheral nerve block with bupivacaine (SPNB+B) alone.

METHODS

Consecutive ACLR patients with or without meniscal surgery by a single surgeon were enrolled. All received a preoperative single-shot adductor canal peripheral nerve block with either admixture of liposomal bupivacaine injectable suspension with 0.25% bupivacaine (SPNB+BL) or 0.25% bupivacaine alone (SPNB+B). Postoperative pain management included cryotherapy, oral acetaminophen, and ibuprofen. A prescription for 10 doses of hydrocodone/acetaminophen (5/325 mg) was provided in a sealed envelope with instructions to only use in the case of uncontrolled pain. Pain using the visual analog scale; number of consumed narcotics, acetaminophen, ibuprofen, and pain treatment satisfaction for the first 3 postoperative days were recorded. Statistical analysis was performed.

RESULTS

Fifty-eight patients were enrolled, the average age was 15±1.5 years (SPNB+B=32 patients, SPNB+BL=26 patients). Forty-seven patients (81%) did not require home opioids postoperatively. A significantly lower proportion of patients in the SPNB+BL group required opioids compared with control patients (7.7% vs. 28.1%, P=0.048). Average opioid use was 2 morphine milligram equivalents (MME), 0.4 pills (range, 0 to 20 MME). There were no differences in the visual analog scale or pain treatment satisfaction scores, other demographics, or other operative data. Inverse probability of treatment weighting analysis that was performed to account for any potential group differences revealed home opioid use between groups is significantly different (P<0.001).

CONCLUSIONS

Liposomal bupivacaine injectable suspension admixture administered as an adductor canal nerve block in adolescents undergoing ACLR effectively reduces home opioid usage postoperatively compared with bupivacaine alone.

LEVEL OF EVIDENCE

Level II-prospective comparative study.

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.

Pro and Con: How Important Is the Exact Location of Adductor Canal and Femoral Triangle Blocks?

In this Pro-Con commentary article, we debate the importance of anterior thigh block locations for analgesia following total knee arthroplasty. The debate is based on the current literature, our understanding of the relevant anatomy, and a clinical perspective. We review the anatomy of the different fascial compartments, the course of different nerves with respect to the fascia, and the anatomy of the nerve supply to the knee joint. The Pro side of the debate supports the view that more distal block locations in the anterior thigh increase the risk of excluding the medial and intermediate cutaneous nerves of the thigh and the nerve to the vastus medialis, while increasing the risk of spread to the popliteal fossa, making distal femoral triangle block the preferred location. The Con side of the debate adopts the view that while the exact location of local anesthetic injection appears anatomically important, it has not been proven to be clinically relevant.

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.

Motor-Sparing Effect of Adductor Canal Block for Knee Analgesia: An Updated Review and a Subgroup Analysis of Randomized Controlled Trials Based on a Corrected Classification System

OBJECTIVE

Discrepancies in the definition of adductor canal block (ACB) lead to inconsistent results. To investigate the actual analgesic and motor-sparing effects of ACB by anatomically defining femoral triangle block (FTB), proximal ACB (p-ACB), and distal ACB (d-ACB), we re-classified the previously claimed ACB approaches according to the ultrasound findings or descriptions in the corresponding published articles. A meta-analysis with subsequent subgroup analyses based on these corrected results was performed to examine the true impact of ACB on its analgesic effect and motor function (quadriceps muscle strength or mobilization ability). An optimal ACB technique was also suggested based on an updated review of evidence and ultrasound anatomy.

MATERIALS AND METHODS

We systematically searched studies describing the use of ACB for knee surgery. Cochrane Library, PubMed, Web of Science, and Embase were searched with the exclusion of non-English articles from inception to 28 February 2022. The motor-sparing and analgesic aspects in true ACB were evaluated using meta-analyses with subsequent subgroup analyses according to the corrected classification system.

RESULTS

The meta-analysis includes 19 randomized controlled trials. Compared with the femoral nerve block group, the quadriceps muscle strength (standardized mean difference (SMD) = 0.33, 95%-CI [0.01; 0.65]) and mobilization ability (SMD = -22.44, 95%-CI [-35.37; -9.51]) are more preserved in the mixed ACB group at 24 h after knee surgery. Compared with the true ACB group, the FTB group (SMD = 5.59, 95%-CI [3.44; 8.46]) has a significantly decreased mobilization ability at 24 h after knee surgery.

CONCLUSION

By using the corrected classification system, we proved the motor-sparing effect of true ACB compared to FTB. According to the updated ultrasound anatomy, we suggested proximal ACB to be the analgesic technique of choice for knee surgery. Although a single-shot ACB is limited in duration, it remains the candidate of the analgesic standard for knee surgery on postoperative day 1 or 2 because it induces analgesia with less motor involvement in the era of multimodal analgesia. Furthermore, data from the corrected classification system may provide the basis for future research.

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.

Benefits of Implementing an Enhanced Recovery After Surgery Protocol in Ambulatory Surgery

BACKGROUND

Enhanced recovery after surgery (ERAS) protocols in orthopaedic surgery have garnered significant focus due to their ability to control pain adequately in the immediate postoperative window, allowing for earlier mobilization, shorter hospital stays, and fewer complications. Virginia Commonwealth University created a multimodal pain management approach in which patients receive a preoperative femoral nerve block followed by periarticular intraoperative local injection anesthesia consisting of bupivacaine, ketamine, and ketorolac.

HYPOTHESIS

We hypothesized that implementation of the ERAS protocol will decrease postoperative pain scores, decrease recovery time in the postanesthesia care unit (PACU), and decrease opioid use in anterior cruciate ligament (ACL) reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Two patient cohorts were involved: before ERAS implementation (pre-ERAS) and after (post-ERAS). Patients with ACL reconstruction only and patients with ACL reconstruction with meniscal repair were analyzed separately. Post-ERAS patients received an intraoperative periarticular injection of bupivacaine, ketamine, and ketorolac and a postoperative multimodal pain regimen. Outcomes included time spent in the PACU, short-term and long-term opioid consumption, and pain score at discharge from the PACU.

RESULTS

Compared with pre-ERAS patients, post-ERAS patients had decreased pain (2.1 vs 0.84 out of 10, respectively), spent less time in the PACU (79.4 vs 62.8 minutes, respectively), and had less opioid consumption in the immediate postoperative period (4.55 vs 2.26 total morphine milligram equivalents [MMEs], respectively) (P < .001 for all). After ERAS implementation, long-term MME use decreased from 410 to 321 between 0 and 2 weeks postoperatively, 92.6 to 1.69 between 2 and 6 weeks, and 494.5 to 323 between 0 and 6 weeks (P < .001 for all). All domains showed significant improvements for both the ACL and the ACL plus meniscal repair cohorts, with the exception of pain at discharge in the ACL plus meniscal repair group.

CONCLUSION

The study findings suggest that an enhanced recovery pathways protocol that includes a standardized intraoperative periarticular bupivacaine, ketamine, and ketorolac injection improves pain scores in the immediate postoperative window, decreases opioid consumption, and reduces recovery time in the PACU for patients undergoing ACL reconstruction.

Liposomal Bupivacaine Decreases Post-Operative Opioid Use after Anterior Cruciate Ligament Reconstruction: A Review of Level I Evidence

Introduction

Anterior Cruciate Ligament tears are common after a non-contact injury and several thousand reconstructions (ACLR) occur yearly in the United States. Multimodal pain management has evolved greatly to include nerve blocks to minimize physical therapy losses post-operatively, pericapsular and wound injections, and other adjunctive measures. However, there is a surprisingly high use of opioid use after ACLR.

Objective

The purpose of present investigation is to summarize the current state of knowledge regarding opioid use after ACLR and to synthesize the literature regarding the use of liposomal bupivacaine and its potential to reduce post-operative opioid use in ACLR patients.

Methods

The literature search was performed in Mendeley. Search fields were varied until redundant. All articles were screened by title and abstract and a preliminary decision to include an article was made. A full-text screening was performed on the selected articles. Any question regarding the inclusion of an article was discussed by three authors until an agreement was reached.

Results

Eighteen articles summarized the literature around the opioid epidemic in ACL surgery and the current context of multimodal pain strategies in ACLR. Five primary articles directly studied the use of liposomal bupivacaine as compared to reasonable control options. There remains to be over prescription of opioids within orthopedic surgery. Patient and prescriber education are effective methods at decreasing opioid prescriptions. Many opioid pills prescribed for ACLR are not used for the correct purpose. Several risk factors have been identified for opioid overuse in ACLR: American Society of Anesthesiologists score, concurrent meniscal/cartilage injury, preoperative opioid use, age < 50, COPD, and substance abuse disorder. Liposomal bupivacaine is effective in decreasing post-operative opioid use and reducing post-operative pain scores as compared to traditional bupivacaine. LB may also be effective as a nerve block, though the data on this is more limited and the effects on post-operative therapy need to be weighed against the potential therapeutic benefit. LB is associated with significantly greater costs than traditional bupivacaine.

Discussion

The role for opioid medications in ACLR should continue to decrease over time. Liposomal bupivacaine is a powerful tool that can reduce post-operative opioid consumption in ACLR.

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.

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.

Do Continuous Peripheral Nerve Blocks Decrease Home Opioid Use Following Anterior Cruciate Ligament Reconstruction in Children and Adolescents? The Envelope Please

BACKGROUND

Levels of opioid misuse and addiction among children and adolescents have reached alarming proportions. Exposure to opioids after surgery for anterior cruciate ligament reconstruction (ACLR), which is commonly performed in young athletes, increases this risk. This study was designed to evaluate whether continuous peripheral nerve block (CPNB) with placement of an elastomeric reservoir ball, compared with single-shot peripheral nerve block (SPNB), would decrease the need for home opioid analgesia and improve pain control after ACLR in children and adolescents.

METHODS

Prospectively collected data from a consecutive cohort that underwent ACLR by a single surgeon were retrospectively reviewed. Patients who received ACLR with 72-hour CPNB were assigned to Group 1. Patients who received ACLR with SPNB were assigned to Group 2. Postoperative pain management included cryotherapy, oral acetaminophen, and ibuprofen. A prescription for 10 doses of hydrocodone/acetaminophen (5/325 mg) was provided in a sealed envelope with instructions that the prescription should only be used in the case of uncontrolled pain. Reports of no opioid use were corroborated by the unopened envelope and unfilled prescription.

RESULTS

One hundred and ninety-six patients were enrolled in the study (SPNB=114 patients, CPNB=82 patients). Average age was 15±1.5 years (115 female). A total of 138 patients (70%) did not need home opioid analgesia after surgery. Of the 58 patients (30%) that did there were 35 (30.7%) in the SPNB group and 23 (28.0%) in the CPNB group (P=0.659). There were no differences between groups in demographics, operative data, or visual analog scale scores on any postoperative day.

CONCLUSION

The findings of this study demonstrate equivalent pain control and opioid consumption in children and adolescents undergoing ACLR treated with either a CPNB or a SPNB. At-home opioid analgesia use can be negated after ACLR in 70% of children and adolescents. For the patients in this study who required opioids, average use was only 2 pills of 5 mg hydrocodone/325 mg acetaminophen, with no child using more than 10 pills.

LEVEL OF EVIDENCE

Level II-therapeutic.

Liposomal Bupivacaine and Ropivacaine Adductor Canal Blocks for Anterior Cruciate Ligament Reconstruction Provide Similar Postoperative Analgesia

The purpose of this study was to compare postoperative pain following anterior cruciate ligament (ACL) reconstruction (ACLR) in patients receiving an adductor canal block (ACB) with ropivacaine (R-ACB) or liposomal bupivacaine (LB-ACB). The secondary purpose was to compare opioid consumption. A prospective cohort study of patients undergoing ACLR at an academic medical center was conducted from November 1, 2018 to November 21, 2019. The first cohort received R-ACB and 30 tablets of 5/325 mg oxycodone/acetaminophen. After June 13, 2019, the second cohort received LB-ACB and 20 tablets of 5/325 mg oxycodone/acetaminophen with the reduction in opioids prescribed resulting from a hospital quality improvement initiative to decrease narcotic consumption. From postoperative days 0 through 6, pain was assessed thrice daily using a numeric rating scale. Total postoperative opioid consumption was reported via tablet count and converted to oral morphine equivalents (OMEs). During this period, 165 subjects underwent ACLR, and 126 met the eligibility criteria (44.4% female, 55.6% male; mean ± standard deviation: 28.7 ± 13.7 years). Sixty-six (52.4%) received LB-ACB, and 60 (47.6%) received R-ACB (p = 0.53). The most common graft utilized was quadriceps autograft (63.6% LB-ACB; 58.3% R-ACB, p = 0.76). Mean postoperative pain scores were similar between groups during the entire postoperative period (p ≥ 0.08 for POD 0-6). While postoperative opioid consumption was lower among patients receiving LB-ACB (median OME [interquartile range]: 28.6 [7.5-63.8] vs. 45.0 [15.0-75.0], p = 0.023), this only amounted to an average of 2.2 tablets. Patients receiving LB-ACB in the setting of ACLR reported similar postoperative pain compared with those receiving R-ACB. Despite the second aim of our study, we cannot make conclusions about the effect of each block on opioid consumption given that each cohort received different numbers of opioid tablets due to institutional pressure to reduce opioid prescribing. As few patients completed their opioid prescriptions or requested refills, further reduction in prescription size is warranted. Future studies are necessary to further elucidate the effect of LB-ACB versus R-ACB on postoperative pain and opioid consumption after ACLR.

Regional anesthesia for orthopedic procedures: What orthopedic surgeons need to know

Regional anesthesia is an integral component of successful orthopedic surgery. Neuraxial anesthesia is commonly used for surgical anesthesia while peripheral nerve blocks are often used for postoperative analgesia. Patient evaluation for regional anesthesia should include neurological, pulmonary, cardiovascular, and hematological assessments. Neuraxial blocks include spinal, epidural, and combined spinal epidural. Upper extremity peripheral nerve blocks include interscalene, supraclavicular, infraclavicular, and axillary. Lower extremity peripheral nerve blocks include femoral nerve block, saphenous nerve block, sciatic nerve block, iPACK block, ankle block and lumbar plexus block. The choice of regional anesthesia is a unanimous decision made by the surgeon, the anesthesiologist, and the patient based on a risk-benefit assessment. The choice of the regional block depends on patient cooperation, patient positing, operative structures, operative manipulation, tourniquet use and the impact of post-operative motor blockade on initiation of physical therapy. Regional anesthesia is safe but has an inherent risk of failure and a relatively low incidence of complications such as local anesthetic systemic toxicity (LAST), nerve injury, falls, hematoma, infection and allergic reactions. Ultrasound should be used for regional anesthesia procedures to improve the efficacy and minimize complications. LAST treatment guidelines and rescue medications (intralipid) should be readily available during the regional anesthesia administration.

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.

Improving day surgery rates of anterior cruciate ligament reconstruction surgery in surgical units not dedicated to performing day surgery: A retrospective observational cohort study

BACKGROUND AND AIMS

Current guidance advises that at least 90% of anterior cruciate ligament reconstructions are performed as day-case operations. Same-day surgery rates achieved by surgical units have significant clinical and financial implications. The primary aim of this multi-centre study was to determine the rate of admission and causes for admissions in patients undergoing anterior cruciate ligament reconstruction.

METHOD

Patient documentations were studied for those who underwent an elective anterior cruciate ligament reconstruction between January 2015 and April 2019. Contributing factors related to admission length were investigated and included patient age, gender, body mass index (BMI), operating surgeon, operating hospital, American Society of Anaesthesiology (ASA) grade, and position of the patient on the operating list. Both univariate and multivariate analysis were conducted using the STATA/IC 16.1 statistical package.

RESULTS

The day surgery rate of anterior cruciate ligament reconstructions were 52% (50/95). Patients positioned later on the operating list were more likely to be admitted post-operatively (OR, 4.49; P = .002; 95% CI, 1.72-11.69) and this was the only factor associated with admission. A large majority of admitted patients (95.6%) were admitted without a clinical cause and were otherwise safe for same-day discharge.

CONCLUSIONS

The day surgery rate for ACL reconstruction remains low, despite an extremely low complication rate. Reconfiguration of the operating lists and positioning anterior cruciate ligament reconstructions earlier in the day will likely increase the same-day discharge rate and reduce associated costs.

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.

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.

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.

Intra-articular Morphine and Ropivacaine Injection Provides Efficacious Analgesia As Compared With Femoral Nerve Block in the First 24 Hours After ACL Reconstruction: Results From a Bone-Patellar Tendon-Bone Graft in an Adolescent Population

Background:

Opioid consumption and patient satisfaction are influenced by a surgeon’s pain-management protocol as well as the use of adjunctive pain mediators. Two commonly utilized adjunctive pain modifiers for anterior cruciate ligament (ACL) reconstruction are femoral nerve blockade and intra-articular injection; however, debate remains regarding the more efficacious methodology.

Hypothesis:

We hypothesized that intra-articular injection with ropivacaine and morphine would be found to be as efficacious as a femoral nerve block for postoperative pain management in the first 24 hours after bone–patellar tendon–bone (BTB) ACL reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Charts were retrospectively reviewed for BTB ACL reconstructions performed by a single pediatric orthopaedic surgeon from 2013 to 2019. Overall, 116 patients were identified: 58 received intra-articular injection, and 58 received single-shot femoral nerve block. All patients were admitted for 24 hours. Pain scores were assessed every 4 hours. Morphine milligram equivalents (MMEs) consumed were tabulated for each patient.

Results:

Opioid use was 24.3 MMEs in patients treated with intra-articular injection versus 28.5 MMEs in those with peripheral block (P = .108). Consumption of MMEs was greater in the intra-articular group in the 0- to 4-hour period (7.1 vs 4.6 MMEs; P = .008). There was significantly less MME consumption in patients receiving intra-articular injection versus peripheral block at 16 to 20 hours (3.2 vs 5.6 MMEs; P = .01) and 20 to 24 hours (3.8 vs 6.5 MMEs; P < .001). Mean pain scores were not significantly different over the 24-hour period (peripheral block, 2.7; intra-articular injection, 3.0; P = .19).

Conclusion:

Within the limitations of this study, we could identify no significant difference in MME consumption between the single-shot femoral nerve block group and intra-articular injection group in the first 24 hours postoperatively. While peripheral block is associated with lower opioid consumption in the first 4 hours after surgery, patients receiving intra-articular block require fewer opioids 16 to 24 hours postoperatively. Given these findings, we propose that intra-articular injection is a viable alternative for analgesia in adolescent patients undergoing BTB ACL reconstruction.

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.

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

BACKGROUND

Femoral nerve block (FNB) is considered the preferred analgesia after anterior cruciate ligament reconstruction (ACLR), but leads to weakness in the quadriceps muscles. Adductor canal block (ACB) is a new sensory block technique that effectively relieves postoperative pain while preserving quadriceps strength. The purpose of our study was to compare the efficacy of FNB vs ACB for pain control after ACLR.

METHODS

This prospective, randomized, double-blind, controlled, superiority clinical trial was approved by the institutional review board in our university hospital. We enrolled 120 patients set to undergo ACLR in this randomized therapeutic trial. Sixty patients received FNB and the other 60 received ACB for postoperative pain control. All ACB and FNB were performed using ultrasound-guided single-shot procedures. The primary outcomes included maximum voluntary isovolumetric contraction and postoperative pain score. Secondary outcomes included total opioid consumption, length of hospital stay, complication, and satisfaction score.

RESULTS

This clinical trial might provide some insights to estimate and compare the safety and efficacy of ACB vs FNB following ACLR.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (researchregistry5569).

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.

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.

Comparison of Continuous Adductor Canal and Femoral Nerve Blocks for Analgesia and Return of Quadriceps Function After Anterior Cruciate Ligament Reconstruction in Adolescent Patients

PURPOSE

To compare early pain relief and late quadriceps function after anterior cruciate ligament reconstruction (ACLR) with hamstring autograft in adolescent patients treated with either a continuous femoral nerve block (cFNB) or continuous adductor canal block (cACB).

METHODS

We retrospectively reviewed a consecutive series of adolescent patients who underwent ACLR and received either a cACB or cFNB for postoperative pain management. Over a 1-year period, all patients underwent ACLR with cFNBs. Over the subsequent 9 months, all patients underwent their ACLR with cACBs. Patient demographics, postoperative pain scores, opioid consumption, satisfaction and complications, and dates and results of quadriceps function derived at the Return to Sports evaluation were compared.

RESULTS

Ninety-one patients (53 cFNB, 38 cACB) were reviewed. There were no differences in the demographics of the 2 groups. There were no statistically significant differences between groups in variations in postoperative pain scores (P = .21), or satisfaction with the blocks (P = .93). Patients in the cFNB group consumed a greater number of opioid doses on postoperative day 3 (2.2 ± 2.1 doses cFNB, 1.1 ± 1.6 doses cACB, P = .03) and a greater number of opioid doses overall for postoperative days 1 to 3 (mean 6.8 ± 5.3 doses cFNB, 3.8 ± 2.1 doses cACB, P = .03). There was no difference in time to return of acceptable quadriceps strength and function when comparing the 2 groups (30.9 ± 7.7 weeks cFNB, 28.9 ± 6.6 weeks cACB, P = .087).

CONCLUSIONS

We found few differences in postoperative analgesic requirements when comparing patients who underwent ACLR with hamstring autograft with a cACB to those who underwent a similar procedure with a cFNB. Return of quadriceps strength and function by six months did not appear to vary with regional technique, either cACB or cFNB, employed at surgery.

LEVEL OF EVIDENCE

III, Retrospective comparative study.

Does Rebound Pain after Peripheral Nerve Block for Orthopedic Surgery Impact Postoperative Analgesia and Opioid Consumption? A Narrative Review

Regional anesthesia has been considered a great tool for maximizing post-operative pain control while minimizing opioid consumption. Post-operative rebound pain, characterized by hyperalgesia after the peripheral nerve block, can however diminish or negate the overall benefit of this modality due to a counter-productive increase in opioid consumption once the block wears off. We reviewed published literature describing pathophysiology and occurrence of rebound pain after peripheral nerve blocks in patients undergoing orthopedic procedures. A search of relevant keywords was performed using PubMed, EMBASE, and Web of Science. Twenty-eight articles (n = 28) were included in our review. Perioperative considerations for peripheral nerve blocks and other alternatives used for postoperative pain management in patients undergoing orthopedic surgeries were discussed. Multimodal strategies including preemptive analgesia before the block wears off, intra-articular or intravenous anti-inflammatory medications, and use of adjuvants in nerve block solutions may reduce the burden of rebound pain. Additionally, patient education regarding the possibility of rebound pain is paramount to ensure appropriate use of prescribed pre-emptive analgesics and establish appropriate expectations of minimized opioid requirements. Understanding the impact of rebound pain and strategies to prevent it is integral to effective utilization of regional anesthesia to reduce negative consequences associated with long-term opioid consumption.

Effects of adductor canal block versus femoral nerve block in patients with anterior cruciate ligament reconstruction: A protocol for a systematic review and meta-analysis

OBJECTIVE

It is reported that both adductor canal block (ACB) and femoral nerve block (FNB) are commonly used methods for postoperative analgesia in anterior cruciate ligament (ACL) reconstruction. Currently, no record has compared the efficacy of postoperative pain relief and the influence to quadriceps strength between them. This study aims to provide a protocol to compare the efficacy and safety between ACB and FNB for the postoperative analgesia of ACL reconstruction.

METHODS

This study will be performed in accordance with the guideline of the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols. Online databases including PubMed, Embase, Web of Science, Cochrane Library, Wanfang database, and the Chinese National Knowledge Infrastructure database will be systematically searched from their inception up May 31, 2019. All randomized controlled trials will be included in present meta-analysis. The quality of enrolled literatures will be evaluated by using the Cochrane Collaboration Risk of bias Tool. Statistical analysis will be calculated by the Review Manager 5.3.

RESULTS

This review will investigate the efficacy and safety of ACB compared with FNB in patients undergoing ACL reconstruction. The primary outcomes are visual analog scale, cumulative opioid consumption during 24 hours after surgery, numerical rating scale, and the time to first straight-leg raise. The secondary outcomes include maximal voluntary isometric contraction, stretching torque at 3, 6 months' follow-up, and adverse effects.

CONCLUSION

Findings of this systematic review and meta-analysis will summarize the current evidence in postoperative analgesia for ACL reconstruction and also provide implications for clinical practice.

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.