title: The Analgesic Effect of Obturator Nerve Block Added to a Femoral Triangle Block After Total Knee Arthroplasty: A Randomized Controlled Trial.
abstract: OBJECTIVE
  Total knee arthroplasty (TKA) is associated with severe pain, and effective analgesia is essential for the quality of postoperative care and ambulation. The analgesic effects of adding an obturator nerve block (ONB) to a femoral triangle block (FTB) after TKA have not been tested previously. We hypothesized that combined ONB and FTB will reduce opioid consumption and pain compared with those of a single FTB or local infiltration analgesia (LIA).
  
  
  METHODS
  Seventy-eight patients were randomized to combined ONB and FTB, single FTB, or LIA after primary unilateral TKA. The primary outcome was morphine consumption during the first 24 postoperative hours. Secondary outcomes included morphine consumption during the first 48 postoperative hours, pain at rest and passive knee flexion, nausea and vomiting, cumulated ambulation score, and Timed Up and Go test.
  
  
  RESULTS
  Seventy-five patients were included in the analysis. The total intravenous morphine consumption during the first 24 postoperative hours was 2 mg (interquartile range [IQR], 0-15) in the combined ONB and FTB group, 20 mg (IQR, 10-26) in the FTB group (P = 0.0007), and 17 mg (IQR, 10-36) in the LIA group (P = 0.002). The combined ONB and FTB group displayed reduced pain, nausea, and vomiting compared with the other groups. The ambulation tests showed no statistically significant differences between the groups.
  
  
  CONCLUSIONS
  Addition of ONB to FTB significantly reduced opioid consumption and pain after TKA compared with a single FTB or LIA, without impaired ambulation.
authors.affiliation: From the *Elective Surgery Centre, Silkeborg Regional Hospital, Silkeborg; †Department of Anesthesiology, Zealand University Hospital, Roskilde; and ‡Department of Anesthesiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Runge
authors.forename: Jens
authors.initials: J
authors.lastname: Børglum
authors.forename: Jan Mick
authors.initials: JM
authors.lastname: Jensen
authors.forename: Tina
authors.initials: T
authors.lastname: Kobborg
authors.forename: Anette
authors.initials: A
authors.lastname: Pedersen
authors.forename: Jon
authors.initials: J
authors.lastname: Sandberg
authors.forename: Lone Ramer
authors.initials: LR
authors.lastname: Mikkelsen
authors.forename: Morten
authors.initials: M
authors.lastname: Vase
authors.forename: Thomas Fichtner
authors.initials: TF
authors.lastname: Bendtsen
mesh_terms: D061605:Administration, Intravenous; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D001696:Biomechanical Phenomena; D003718:Denmark; D005260:Female; D005267:Femoral Nerve / Q000000981:diagnostic imaging; D006801:Humans; D007719:Knee Joint / Q000294:innervation / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D009776:Obturator Nerve / Q000000981:diagnostic imaging; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D020250:Postoperative Nausea and Vomiting / Q000209:etiology / Q000517:prevention & control; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine