ACL and regional nerve blocks-To Do or Not To Do?
Rita Agarwal MD, FAAP, FASA , Deepa Kattail MD, MHS
Original article
Sadacharam K, Mandler T, Staffa SJ, Pestieau SR, Fuller C, Ellington M, Sparks JW, Fernandez AM; SPAIN-ACL Investigators. Regional Anesthesia and Pain Outcomes After Anterior Cruciate Ligament Reconstruction Surgery in Pediatric Patients: Society of Pediatric Anesthesia Improvement Network. Anesth Analg. 2025 Jan 29. doi: 10.1213/ANE.0000000000007376. Epub ahead of print. PMID: 39879136.
About a year ago our previously very supportive orthopedic surgeons decided that they no longer wanted peripheral nerve blocks placed in their patients undergoing anterior cruciate ligament (ACL) reconstruction or other knee operations. We actually have very good interactions with our surgeons, so this came as a big surprise. Especially since they alluded to studies that showed that blocks did not help post-operative pain at home and may not affect opioid prescription rates, and some vague references to persistent complications in a few of their patients. Exposure to opioids postoperatively in adolescents undergoing ACL repair has been associated with an increase in misuse of opioids,1 so decreasing opioid prescriptions could potentially decrease the incidence opioid misuse in most studies in adult patients nerve blocks have clearly shown a decrease in opioid use. None of it made sense to us, but we found other ways to manage pain in these patients.
In October I (RA) stumbled across a letter to the editor by Kattail et al.2 referencing a study done by some of the pediatric orthopedic surgeons here at Stanford, regarding opioid use after single shot peripherally nerve blocks ( Kaur et.al.).3 The authors used a large deidentified database from a commercial insurance company to compare opioid prescriptions, number of refills, and trips to the ED for poorly controlled pain. The study measured opioid consumption in morphine milligram equivalents (MME) by calculating the amount of opioid pills prescribed, and acknowledged the number of pills prescribed may not reflect doses actually consumed by the patient. Mean age of adolescents was 16, all other demographics appeared to be similar. Surprisingly the original study showed that the addition of a peripheral nerve block led to higher incidence of opioid use after ACL surgery. There were more prescriptions written and for higher amounts. How can this be? Dr Kattail and colleagues pointed out all the flaws in the study, including the most important that this was a retrospective study that did not measure pain levels or evaluate the quality of the blocks performed. There is no causality just correlation. Both articles emphasized the importance of optimizing pain relief after surgery and minimizing the exposure of adolescents to opioids and ponder the importance of prospective studies to help elucidate the issues, which leads us to ….The Society for Pediatric Anesthesia Information Network (SPAIN) has been working for several years on this very topic.4,5 This is a multi-institutional group that has performed a prospective observational study on children undergoing ACL reconstruction. Over 500 adolescents aged 12-17 were recruited from 15 different institutions. Perioperative data was gathered including demographic, ASA status, surgical details (tourniquet use, duration, use of graft etc), timing, type and use of regional analgesia adverse events and pain scores, discharge times and post-operative opioid use. Patients were surveyed on postoperative day 1, 3, postoperative week 6 and 6 months after surgery. The median age of patients was 15, 94% presented with a sports related injury. ~56 % were female and 64% were white. Eighty six % received some sort of regional technique for postoperative analgesia, the remainder had intra-articular infiltration). Types of blocks are listed in the Table below. Of the patients who received a block, ~1/2 had a single nerve block (adductor canal block being the most common) and the rest received some sort of combination block. Most just received local anesthetic in their blocks, but some received a variety of adjuvants.
But of course the real question is did Sadacharam and Mandler et. al find any difference in postoperative pain and opioid consumption?
Yes they did! In the PACU and POD 1 there were better pain scores and less use of opioids in the patients who received a combination of an anterior (adductor canal, or femoral nerve) and posterior (popliteal, IPACK etc) block. This difference was minimal at day 3 and very few patients in any of the groups had persistent pain at 6 week or 6 months. Equally as importantly their investigation revealed “a significant number of patients experienced severe postoperative pain in PACU (32.7%), on POD 1 (25.7%) and POD 3 (10%), indicating limitations of current pain management modalities during and beyond the immediate postoperative period.”4
Reports of persistent numbness occurred in 11.1% at 6 weeks, and 15.5% at 6 months in patients who received a block. 4.1% and 2.1% of patients reported persistent weakness at 6 weeks and 6 months, with the use of higher concentrations (>0.25%) of local anesthetic and methylprednisolone being significantly associated with persistent numbness.
The SPAIN-ACL group is to be commended, prospective studies such as these are extremely difficult to conduct, but they clearly reveal areas that need further study and raise more questions than answers.
It will be interesting to see if the advent of some of the newer medications that have been approved by the FDA ( for use in adults right now) or are in development, such as suzetrigine,6,7 vocacapsacian (see the excellent PAAD by Dr Elliot Krane https://ronlitman.substack.com/p/bolo-alert-vocacapsaicin-has-the?utm_source=publication-search ) and Zynrelef ( bupivacaine/meloxicam)8 can decrease the incidence of severe pain experienced by patients undergoing ACL reconstructions.
What do you do in your practices? Will the results of any of these studies change your practice? As always please share your comments and thoughts with us and Myron will post in a Friday reader response.
References
1. Cahan EM, Halvorsen KC, Pham NS, et al. Opioid Represcriptions After ACL Reconstruction in Adolescents Are Associated With Subsequent Opioid Use Disorder. Journal of pediatric orthopedics 2023;43(4):e273-e277. (In eng). DOI: 10.1097/bpo.0000000000002340.
2. Kattail D, Hagen JG, Alrayashi W. Peripheral Nerve Blocks and Opioid Use After ACL Reconstruction in Adolescents. Orthopedics 2024;47(5):261-262. (In eng). DOI: 10.3928/01477447-20240808-01.
3. Kaur J, Pham NS, Cahan E, et al. Use of Peripheral Nerve Blocks Is Not Associated With Decreased Postoperative Opioid Prescription After ACL Reconstruction in Adolescents. Orthopedics 2024;47(2):83-88. (In eng). DOI: 10.3928/01477447-20230616-05.
4. Sadacharam K, Mandler T, Staffa SJ, et al. Regional Anesthesia and Pain Outcomes After Anterior Cruciate Ligament Reconstruction Surgery in Pediatric Patients: Society of Pediatric Anesthesia Improvement Network. Anesthesia and analgesia 2025 (In eng). DOI: 10.1213/ane.0000000000007376.
5. Sadacharam K, Furstein JS, Staffa SJ, et al. Multisite prospective study of perioperative pain management practices for anterior cruciate ligament reconstruction in adolescents: Society for Pediatric Anesthesia Improvement Network (SPAIN) Project Report. Regional anesthesia and pain medicine 2024 (In eng). DOI: 10.1136/rapm-2024-105381.
6. Osteen JD, Immani S, Tapley TL, et al. Pharmacology and Mechanism of Action of Suzetrigine, a Potent and Selective Na(V)1.8 Pain Signal Inhibitor for the Treatment of Moderate to Severe Pain. Pain and therapy 2025 (In eng). DOI: 10.1007/s40122-024-00697-0.
7. Hang Kong AY, Tan HS, Habib AS. VX-548 in the treatment of acute pain. Pain management 2024;14(9):477-486. (In eng). DOI: 10.1080/17581869.2024.2421749.
8. Bourn T, Serpa SM. Bupivacaine/meloxicam ER: A New Dual-acting Extended-Release Local Anesthetic for Opioid-Sparing Postoperative Pain Management. The Annals of pharmacotherapy 2023;57(1):71-85. (In eng). DOI: 10.1177/10600280221086639.