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Journal of Clinical Anesthesia and Pain Medicine

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Research Article

Effect of Adductor Canal Saphenous Nerve Block on Perioperative Pain Management for Children Undergoing Anterior Cruciate Ligament Repair

Mofya S Diallo, Katherine E Negreira, Heather Gordish Dressman, Kaleb L Friend and Sophie R Pestieau

Correspondence Address :

Children’s National Hospital,
111 Michigan Avenue,
N.W.Washington, DC 20010,
United States of America

Received on: November 07, 2019, Accepted on: November 19, 2019, Published on: November 26, 2019

Citation: Mofya S Diallo, Katherine E Negreira, Heather Gordish Dressman, Kaleb L Friend and SophieR Pestieau (2019). Effect of Adductor Canal Saphenous Nerve Block on Perioperative Pain Management for Children Undergoing Anterior Cruciate Ligament Reconstruction

Copyright: Copyright: 2019 Mofya S Diallo, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

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Abstract
Study objective
To compare the perioperative opioid requirements and immediate postoperative outcomes following adductor canal saphenous nerve block (SNB) vs. femoral nerve block (FNB) vs. local anesthetic injection by the surgeon alone in children undergoing general anesthesia for anterior cruciate ligament (ACL) reconstruction.
Design: Retrospective
Setting: Operating room and post-operative recovery area
Patients: 105 patients, male and female, ages 11 through 18, who underwent ACL reconstruction at Children’s National Health System between July 2014 and July 2017.
Interventions: As part of their intraoperative anesthetic management, patients received a femoral nerve block (FNB), saphenous nerve block (SNB) or local anesthetic injection by the surgeon.
Measurements: Intraoperative, postoperative, and perioperative opioid requirements were examined along with use of other rescue analgesics, postoperative pain scores, post anesthesia care unit (PACU) length of stay, and admission rate.
Main Results: Total intraoperative and perioperative morphine milligram equivalents (MME) were significantly greater in patients who received local anesthetic at the surgical site only vs a FNB (p=0.009 and p=0.017) and vs a SNB (p<0.001 and p<0.001). No significant difference in total intraoperative and perioperative MME was observed between patients receiving a FNB vs a SNB. There were no significant differences in postoperative pain scores, PACU length of stay, admission rates, and postoperative MME between the groups.
Conclusions: Both FNB and SNB significantly decreased intraoperative and perioperative opioid use compared to local anesthesia only in pediatric patients undergoing ACL reconstruction. Larger and prospective studies are needed to further validate the use of
SNB for these patients, where a SNB might be preferred due to its purely sensory blockade.
Keywords: Nerve block, Pediatrics, Anterior cruciate ligament
Fulltext
Introduction
Analysis of youth sports injury studies indicates that most injuries involve the knee and ankle, with ankle injury being the most common and knee injury following closely afterwards. Knee injuries were the most common severe injury causing significant time off from participation in sports and other activities [1]. An increasing incidence of ACL injuries and surgical management have been noted in the pediatric population over the last 20 years due to an increasing participation in organized sports [2,3]. In order to achieve a successful and functional recovery from an ACL reconstruction with a high degree of patient satisfaction, adequate pain management and return of quadriceps and hamstring strength is necessary.

Standard perioperative pain management for ACL surgery in pediatric patients currently includes intravenous (IV) opioids, non-steroidal anti-inflammatory drugs (NSAIDS), acetaminophen, intra-articular injection of opioids and/or local anesthetics or regional anesthesia. Although regional anesthesia is well established in adults undergoing ACL reconstruction, as improving pain control and decreasing opioid induced side effects when compared to IV opioids, there are few studies in pediatrics.
Femoral nerve blocks (FNB) have been shown to shorten hospital stay, reduce opioid requirements, and decrease postoperative pain scores in pediatric patients after arthroscopic knee surgery compared to no block [4]. In their retrospective review, Schloss et al also showed that FNB lower postoperative admission rates. Aside from these benefits, this block has been associated with a decrease in quadriceps and hamstring strength which may increase the risk for falls immediately after surgery [5]. The muscle weakness may delay recovery of muscle function, which can lead to more lasting muscle atrophy, with potential for delay of return to activity [5]. Due to these unfavorable effects, there has been an increased interest in performing the adductor canal saphenous nerve block (SNB) instead, which provides a purely sensory blockade to the knee and medial aspect of the leg below the knee [6]. The perceived benefits of an adductor canal SNB are recognized in the adult population but there is a paucity of data supporting its use in the pediatric population. This retrospective study aims to compare the perioperative opioid requirements and immediate post-operative outcomes following an adductor canal SNB vs a FNB vs local anesthetic injection by the surgeon, in the pediatric population undergoing ACL reconstruction.

Materials and Methods
This is an IRB approved retrospective review of 105 patients, ages 11 through 18, who underwent ACL reconstruction at Childrens National Hospital between July 2014 and July 2017. As part of their intraoperative anesthetic management, patients received a FNB, SNB or local anesthetic infiltration by the surgeon, depending on surgeon preference. It is common practice for pediatric orthopedic surgeons at our institution to infiltrate local anesthetic at the surgical site if a nerve block is not performed due to their preference to reduce post-operative pain. All nerve blocks were placed by pediatric anesthesiologists after induction of general anesthesia and placement of an endotracheal tube (ETT) or laryngeal mask airway (LMA). As is standard at our institution, anesthesia induction involves inhalational induction with sevoflurane and then intravenous (IV) placement or preoperative IV placement and then induction of anesthesia with propofol 2 mg/kg. General anesthesia was maintained with either sevoflurane or desflurane. All patients who received a regional block were given 0.5% ropivacaine, with the exception of two patients in the SNB group who received 0.2% ropivacaine. Patients who did not receive a nerve block by an anesthesiologist were given local anesthetic infiltration at the surgical site by the surgeon. The local anesthetic type and concentration injected varied and depended on surgeon preference: bupivacaine 0.25% with and without morphine, bupivacaine 0.25% with epinephrine with and without morphine, lidocaine 1% with epinephrine. Perioperative opioid requirements were recorded along
with use of other rescue analgesics, postoperative pain scores, post anesthesia care unit (PACU) length of stay, and admission rate. PACU length of stay after an orthopedic procedure in a child at our institution is generally over 90 minutes. This is usually due to our requirement that we observe patients for another 30 minutes after administering any medication in the PACU. Morphine milligram equivalents (MME) were calculated by converting oxycodone doses to IV morphine using a 2:1 ratio, and IV hydromorphone to IV morphine using a 1:5 ratio [7]. Statistical Analysis

All statistical analyses were performed by a statistician using STATA V15 (College Station, TX). Normality of all continuous demographic characteristics and outcomes was assessed with the Shapiro-Wilk normality test and visual inspection of histograms. Those outcomes not normally distributed were analyzed using non-parametric methods. Comparisons of categorical outcomes were performed using Fisher’s exact tests to assess the association between each outcome and nerve block type. Categorical results are presented as frequencies and percentages. Comparisons of normally distributed continuous outcomes were performed using a one-way ANOVA model to compare mean values among the nerve block groups. Where more than two nerve block groups were compared and a significant overall p-value observed, post-hoc pairwise comparisons were performed and the resulting p-values adjusted for multiple comparisons using the Sidak method. Results here are presented as means and standard deviations. Comparisons of non-normally distributed continuous outcomes were performed using a Kruskal-Wallis test. Post-hoc pairwise comparisons using a Wilcoxon rank sum test with p-value adjustment for multiple comparisons were performed where a significant overall effect was observed. Results from nonparametric tests are presented as medians and interquartile ranges. The nominal significance level was set at 0.05.

Results
No significant differences were observed between the groups in regards to demographics, anthropometrics or ASA class (Table 1). A significant association was noted between nerve block group and primary surgeon (p<0.001). Surgeon #1 only administered surgical site local anesthetic and surgeon #2 always used either a FNB or SNB placed by the anesthesiologist. An additional subanalysis of primary surgeon including only surgeons #2, 3 and 4 was performed and there remained a significant association between surgeon and nerve block group. There were no significant differences in length of tourniquet time, whether or not a tourniquet was used, and whether or not an additional procedure was performed (Table 2). There was a significant association between nerve block group and intraoperative administration of dexamethasone (p=0.002) and acetaminophen (p=0.019) administration (Table 2). For dexamethasone use, more patients than not received dexamethasone in the FNB and SNB groups vs. the local only group. For acetaminophen use, more patients than not received acetaminophen in all groups, however, the FNB group had the lowest use. No significant difference was observed with type of airway (ETT or LMA), type of local anesthetic used by surgeon, and use of ketorolac or ondansetron. Significant differences were observed in the amount of local anesthetic used, expressed as volume (ml), milligrams (mg), and mg/ kg (Table 2). The SNB group received less local anesthetic than the FNB group (p=0.032, 0.024, and 0.006). Intraoperative and perioperative morphine milligram equivalents (MME) requirements were significantly lower in the FNB group in comparison to the local only group (p=0.009 and p=0.017). The same was true for the SNB group which received less MME than the local only group (p<0.001 and p<0.001). No significant differences were seen in intraoperative or perioperative MME between the FNB and SNB group (Table 3). No significant difference in average and highest pain score were observed between the SNB, FNB, and local only groups (Table 3). PACU length of stay was significantly longer in the local only group compared to the SNB group (p=0.043), but no difference was observed between the FNB vs SNB group. In the postoperative period, there was a significant difference in use of acetaminophen; the FNB group used it more than the other two groups (Table 4). In addition, there was no statistically significant difference in postoperative admission rates among the three groups (Table 4).

Discussion
This retrospective study showed that in pediatric ACL reconstruction, patients who received local anesthesia without a regional nerve block had greater intraoperative and perioperative opioid use compared with patients who received a FNB or SNB. There were fewer patients with a FNB because as the literature started to show prolonged recovery from FNB, the surgeons who wanted a nerve block preferred we do SNB.
Interestingly, postoperative pain scores were similar amongst all groups. Time in PACU was prolonged by 25 min in patients receiving only local anesthesia by the surgeon and no block compared to a SNB. Although not statistically significant, PACU ength of stay was also prolonged by an average of 18 min for those who received local anesthesia only and no block when compared to the FNB group.
These results are supported by others. In a retrospective study of 376 patients, a FNB was shown to reduce opioid requirements and decrease postoperative pain scores in pediatric patients after arthroscopic knee surgery compared to no block [4]. A randomized trial of 80 patients also showed that compared with intra-articular injection of local anesthetic, FNB allowed for less morphine use after ACL reconstruction [8]. Similarly a meta-analysis comparing analgesic efficacy of local infiltration vs FNB after ACL reconstruction demonstrated that early, intermediate, and late postoperative pain scores were decreased in the FNB group compared to local infiltration only [9]. Our retrospective study differed in that we found no difference in postoperative pain scores between FNB and local only although many other studies note this difference.
Although these benefits are demonstrated, FNBs are associated with a significant decrease in quadriceps and hamstring strength. This decrease in strength has been noted up to 6 months postoperatively in 3 out of 4 testing categories (fast extension, fast flexion, slow flexion) in pediatric and adolescent patients [10]. In this study by Luo et al, patients without a nerve block were 4 to 6 times more likely to meet criteria for return to sports at 6 months compared to those with a FNB. Falls in the adult population have also been observed following a FNB due to decreased muscle strength as well as an increased incidence of "knee bucking" compared to SNB [10-13]. This fall risk is also a concern in the pediatric population.
SNB on the other hand, provide a purely sensory blockade to the knee, sparing quadriceps weakness decreasing the risk of falls [12-21]. Our study showed that the SNB provide analogous and adequate postoperative analgesia in terms of opioid consumption
and pain control when compared to FNB. In a randomized control trial with 11 healthy volunteers, it was found that quadriceps strength decreased by 8% from baseline following an adductor canal SNB compared to a 49% following a FNB [22]. Due to the similar analgesia and opioid requirements when compared to a FNB, a SNB may be the better and safer option for children undergoing ACL reconstruction due to the purely sensory blockade and sparing of quadriceps and hamstring muscles.
In addition, SNB provides decreased perioperative opioid requirements compared to local infiltration which is especially important in this vulnerable population.
Our study has limitations of a retrospective design which relies on accuracy and completeness of chart documentation.
The anesthetic plans and approach varied among patients based on the anesthesiologist and surgeon preferences. This resulted in different nerve block techniques and local anesthetic types and doses. In addition, ACL reconstructions were performed by 4 orthopedic surgeons who may have different techniques and outcomes. This retrospective chart review demonstrates that both FNB and SNB decreased intraoperative and perioperative opioid use compared to local anesthesia only in pediatric patients undergoing ACL reconstruction. Future studies should be conducted to further validate the adductor canal SNB's usefulness in children undergoing ACL reconstruction, specifically comparing the impact of sparing muscle weakness when looking at return to sports between FNB and SNB.

References
1. Caine D, Purcell L, Maffulli N. The child and adolescent athlete: A review of three potentially serious injuries. BMC Sports Sci Med Rehabil. 2014;6(22).
2. Beck NA, Lawrence JTR, Nordin JD, DeFor TA, Tompkins M. ACL tears in school-aged children and adolescents over 20 years. Pediatrics. 2017;139(3).
3. Mall NA, Chalmers PN, Moric M, et al. Incidence and trends of anterior cruciate ligament reconstruction in the United States. Am J Sports Med. 2014;42(10):2363-2370.
4. Schloss B, Bhalla T, Klingele K, Phillips D, Prestwich B, Tobias JD. A retrospective review of femoral nerve block for postoperative analgesia after knee surgery in the pediatric population. J Pediatr Orthop 2014;34(4):459-461.
5. Bailey L, Griffin J, Elliott M, Wu J, Papavasiliou T, Harner C, Lowe W. 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. Arthroscopy.2019;35(3):921-929.
6. Shah RD, Suresh S. Applications of regional anaesthesia in paediatrics. Br J Anaesth 2013 ;1:114-124.
7. Gammaitoni AR, Fine P Alvarez N, McPherson ML, Bergmark S. Clinical application of opiod equianalgesic data. Clin J Pain 2003:19(5):286-297.
8. Iskandar H, Benard A, Ruel-Raymond J, Cochard G, Manaud B. Femoral block provides superior analgesia compared with intra-articular ropivacaine after anterior cruciate ligament reconstruction. Reg Anesth Pain Med. 2003;28(1):29-32.
9. Kirkham KR, Grape S, Martin R, Albrecht E. Analgesic efficacy of local infiltration analgesia vs. femoral nerve block after anterior cruciate ligament reconstruction: a systematic review and meta-analysis. Anaesthesia. 2017;72(12):1542-1553.
10. Luo TD, Ashraf A, Dahm DL, Stuart MJ, McIntosh AL. Femoral nerve block is associated with persistent strength deficits at 6 months after anterior cruciate ligament reconstruction in pediatric and adolescent patients. Am J Sports Med. 2015;43(2):331-336.
11. Thacher RR, Hickernell TR, Grosso MJ, et al. Decreased risk of knee buckling with adductor canal block versus femoral nerve block in total knee arthroplasty: a retrospective cohort study. Arthroplast Today. 2017;3(4):281-285.
12. Muraskin SI, Conrad B, Zheng N, Morey TE, Enneking FK. Falls associated with lower-extremity-nerve blocks: a pilot investigation of mechanisms. Reg Anesth Pain Med 2007;32(1):67-72.
13. Kandasami M, Kinninmonth AW, Sarungi M, Baines J, Scott NB. Femoral nerve block for total knee replacement - A word of caution. Knee. 2009;16(2):98-100.
14. Abdallah FW, Whelan DB, Chan VW, et al. Adductor canal block provides noninferior analgesia and superior quadriceps strength compared with femoral nerve block in anterior cruciate ligament reconstruction. Anesthesiology. 2016;124(5):1053-1064.
15. Chisholm MF, Bang H, Maalouf DB, et al. Postoperative Analgesia with Saphenous Block Appears Equivalent to Femoral Nerve Block in ACL Reconstruction. HSS J. 2014;10(3):245-251.
16. Wang D, Yang Y, Li Q, et al. Adductor canal block versus femoral nerve block for total knee arthroplasty: a meta-analysis of randomized controlled trials. Sci Rep. 2017;7:40721.
17. Kim DH, Lin Y, Goytizolo EA, et al. Adductor Canal Block versus Femoral Nerve Block for Total Knee Arthroplasty: A Prospective, Randomized, Controlled Trial. Anesthesiology. 2014;120(3):540-550.
18. Koh IJ, Choi YJ, Kim MS, Koh HJ, Kang MS, In Y. Femoral Nerve Block versus Adductor Canal Block for Analgesia after Total Knee Arthroplasty. Knee Surg Relat Res. 2017;29(2):87-95.
19. Li D, Ma GG. Analgesic efficacy and quadriceps strength of adductor canal block versus femoral nerve block following total knee arthroplasty. Knee  Surg Sports Traumatol Arthrosc. 2016;24(8):2614-2619.
20. Kwofie MK, Shastri UD, Gadsden JC, et al. The effects of ultrasound-guided adductor canal block versus femoral nerve block on quadriceps strength and fall risk: A blinded, randomized trial of volunteers. Reg Anesth Pain Med. 2013;38(4):321-325.
21. Zhao XQ, Jiang N, Yuan FF, Wang L, Yu B. The comparison of adductor canal block with femoral nerve block following total knee arthroplasty: a systematic review with meta-analysis. J Anesth. 2016;30(5):745-754.
22. Jaeger P, Nielsen ZJ, Henningsen MH, Hilsted KL, Mathiesen O, Dahl JB. Adductor canal block versus femoral nerve block and quadriceps strength: a randomized, double-blind, placebo-controlled, crossover study in healthy volunteers. Anesthesiology 2013;118(2):409-415.
Tables & Figures

Table 1: Demographic and surgical characteristics



Table 2: Intraoperative characteristics


Table 3: Pain outcomes and opioid use


Table 4: Postoperative characteristics

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