{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T21:14:48Z","timestamp":1777929288188,"version":"3.51.4"},"reference-count":41,"publisher":"SAGE Publications","issue":"2","license":[{"start":{"date-parts":[[2022,5,1]],"date-time":"2022-05-01T00:00:00Z","timestamp":1651363200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Sichuan University West China Hospital","award":["ZYJC18040"],"award-info":[{"award-number":["ZYJC18040"]}]}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["J Orthop Surg (Hong Kong)"],"published-print":{"date-parts":[[2022,5]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>\n                      This study aimed to investigate the minimum effective concentration (MEC\n                      <jats:sub>90,<\/jats:sub>\n                      defined as effective in 90% of patients) of ropivacaine during the combined procedure of adductor canal block (ACB) and infiltration between the popliteal artery and capsule of the posterior knee (IPACK) block for patients undergoing total knee arthroplasty.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      This double-blind, randomized dose-finding trial was based on a biased coin up-and-down sequential design, where the concentration of ropivacaine administered to a given patient depended on the previous patient\u2019s response. Before surgery, the first patient received 20\u00a0mL of 0.2% ropivacaine for ACB and again for IPACK. If the block failed, the next subject received a 0.025% higher ropivacaine concentration; otherwise, the next subject received either a 0.025% smaller dose (probability of 0.11) or the same dose (probability of 0.89). The primary outcome was whether the block was successful. Block success was defined as the patient did not suffer significant pain and did not receive rescue analgesia within 6 h after surgery. MEC\n                      <jats:sub>90<\/jats:sub>\n                      was estimated by isotonic regression, and the 95% confidence interval (CI) was calculated by bootstrapping. Secondary outcomes were numerical rating scale (NRS) pain scores at postoperative 24 h and 48 h, postoperative morphine consumption, and time to hospital discharge. Secondary outcomes were compared between patients whose blocks succeeded with those which failed.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Based on analysis of 52 patients, the MEC\n                      <jats:sub>90<\/jats:sub>\n                      was 0.247% (95% CI 0.227\u20130.271%), MEC\n                      <jats:sub>95<\/jats:sub>\n                      was 0.260% (95% CI 0.244\u20130.282%) and MEC\n                      <jats:sub>99<\/jats:sub>\n                      was 0.272% (95% CI 0.260\u20130.291%). In contrast, four of nine trials in a recent systematic review reported ropivacaine concentrations below 0.247%. Patients whose blocks succeeded ( n = 45) had significantly lower NRS pain scores, lower morphine consumption, and shorter hospitalization than patients whose blocks failed ( n = 7).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Our small trial suggests that 0.247% ropivacaine in 20\u00a0mL respectively can provide successful ACB + IPACK block in 90% of patients. However, given that many published trials have used lower concentrations, our findings should be verified in larger studies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/10225536221122339","type":"journal-article","created":{"date-parts":[[2022,8,17]],"date-time":"2022-08-17T04:45:58Z","timestamp":1660711558000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":9,"title":["Minimum effective concentration of ropivacaine for ultrasound-guided adductor canal + IPACK block in total knee arthroplasty"],"prefix":"10.1177","volume":"30","author":[{"given":"Qiuru","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Orthopaedics surgery, West China Hospital, Sichuan University, Chengdu, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jian","family":"Hu","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lijun","family":"Cai","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics surgery, West China Hospital, Sichuan University, Chengdu, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Aergen","family":"Bahete","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics surgery, West China Hospital, Sichuan University, Chengdu, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7167-8829","authenticated-orcid":false,"given":"Pengde","family":"Kang","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics surgery, West China Hospital, Sichuan University, Chengdu, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2022,8,17]]},"reference":[{"key":"bibr1-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1213\/ANE.0000000000003794"},{"key":"bibr2-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.otsr.2010.12.003"},{"key":"bibr3-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1007\/s00167-013-2750-2"},{"key":"bibr4-10225536221122339","first-page":"21","volume":"8","author":"Burns LC","year":"2015","journal-title":"J Pain Res"},{"key":"bibr5-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.arth.2015.06.035"},{"key":"bibr6-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.jor.2016.02.003"},{"key":"bibr7-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1111\/ans.13538"},{"key":"bibr8-10225536221122339","doi-asserted-by":"publisher","DOI":"10.5435\/JAAOS-D-14-00259"},{"key":"bibr9-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1007\/s00264-016-3278-0"},{"key":"bibr10-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.arth.2020.06.060"},{"key":"bibr11-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.arth.2021.05.014"},{"key":"bibr12-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1136\/rapm-2020-101396"},{"key":"bibr13-10225536221122339","unstructured":"Okunlola O, Lai Y, Hebbalasankatte PPB. Addition of ipack block technique to adductor canal block and periarticular local infiltration for knee replacement surgery. In: ASRA 45th annual regional anesthesiology and acute pain medicine meeting. San Francisco, Ca, 2020."},{"key":"bibr14-10225536221122339","unstructured":"Chia P, Wang K, Grogan T. Ipack block has no additional benefit to patients who receive an adductor canal catheter and intraarticular injection for tka. In: ASRA 45th Annual Regional Anesthesiology & Acute Pain Medicine Meeting. San Francisco, Ca, 2020."},{"key":"bibr15-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.arth.2020.01.014"},{"key":"bibr16-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1055\/s-0039-1700840"},{"key":"bibr17-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1007\/s00590-018-2218-7"},{"key":"bibr18-10225536221122339","doi-asserted-by":"publisher","DOI":"10.1016\/j.knee.2019.01.020"},{"key":"bibr19-10225536221122339","unstructured":"Zadoroznijs S. Ipack (interspace between the popliteal artery and the capsule of the posterior knee) block efficiency as aid for acb (adductor canal block) in postoperative analgesia after total knee arthroplasty (pilot study). German clinical trials registerdrks. de, 2019, p. 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