Home > Journals > Minerva Anestesiologica > Past Issues > Minerva Anestesiologica 2018 February;84(2) > Minerva Anestesiologica 2018 February;84(2):168-77



Publication history
Cite this article as


A Journal on Anesthesiology, Resuscitation, Analgesia and Intensive Care

Official Journal of the Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care
Indexed/Abstracted in: Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 2,623




Minerva Anestesiologica 2018 February;84(2):168-77

DOI: 10.23736/S0375-9393.17.11718-9


language: English

Comparing low volume saphenous-obturator block with placebo and femoral-obturator block for anterior cruciate ligament reconstruction

Katja LENZ 1, Kenneth JENSEN 1, Katrine TANGGAARD 2, Mojgan VAZIN 1, Thomas F. BENDTSEN 3, Vincent CHAN 4, Michael R. KROGSGAARD 5, Mikael L. STRUBE 6, Jens BØRGLUM 2

1 Department of Anesthesia and Intensive Care Medicine, Copenhagen University Hospital, Copenhagen, Denmark; 2 Department of Anesthesia and Intensive Care Medicine, Zealand University Hospital, University of Copenhagen, Roskilde, Denmark; 3 Department of Anesthesia and Intensive Care Medicine, Aarhus University Hospital, Nørrebrogade, Denmark; 4 Department of Anesthesia, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada; 5 Section of Sports Traumatology M51, Department of Orthopedic Surgery, Copenhagen University Hospital, Copenhagen, Denmark; 6 National Veterinary Institute, Denmark Technical University, Kongens Lyngby, Denmark


BACKGROUND: Anterior cruciate ligament reconstruction (ACL-RC) is often associated with moderate to severe postoperative pain even with a multimodal analgesic regimen. We aimed to compare the analgesic efficacy of low volume saphenous-obturator block with placebo and femoral-obturator block in patients undergoing ACL-RC.
METHODS: In a randomized controlled trial eighty-two patients undergoing ACL-RC with hamstring autograft were allocated to either low volume saphenous-obturator block, placebo block or femoral-obturator block. Ropivacaine 0.75% was used for active blocks and saline for placebo. Primary outcome was pain-scores at rest quantified as area-under-the-curve 0-6 hr postoperatively. Secondary outcomes were postoperative opioid consumption and pain localization in the knee.
RESULTS: No statistical difference existed between groups in area-under-the-curve 6 hr pain-scores. However, pain-scores were significantly lower in the two ropivacaine groups compared to placebo at emergence t=0 (P<0.018), at t=5 (P<0.042) and at t=6 hours (P<0.002) postoperatively. Furthermore, ropivacaine blocks exhibited significantly reduced total opioid consumption (15.81 and 18.44 mg) postoperatively compared with placebo (26.38 mg) (P<0.018). Patients receiving ropivacaine blocks localized pain in the posterolateral knee, whereas placebo block patients reported anteromedial and central pain. Other secondary outcomes were similar between groups.
CONCLUSIONS: Low volume saphenous-obturator block is significantly more effective than placebo in reducing both early and late pain-scores as well as postoperative opioid consumption in patients undergoing ACL-RC. No statistical difference existed when comparing low volume saphenous-obturator block to femoral-obturator block regarding early and late pain-scores and postoperative opioid consumption.

KEY WORDS: Nerve block - Ultrasonography - Anterior cruciate ligament reconstruction

top of page

Publication History

Issue published online: February 28, 2018
Article first published online: July 26, 2017
Manuscript accepted: July 24, 2017
Manuscript revised: July 17, 2017
Manuscript received: September 21, 2016

Cite this article as

Lenz K, Jensen K, Tanggaard K, Vazin M, Bendtsen TF, Chan V, et al. Comparing low volume saphenous-obturator block with placebo and femoral-obturator block for anterior cruciate ligament reconstruction. Minerva Anestesiol 2018;84:168-77. DOI: 10.23736/S0375-9393.17.11718-9

Corresponding author e-mail