title: Intraarticular analgesia versus epidural plus femoral nerve block after TKA: a randomized, double-blind trial.
abstract: BACKGROUND
  Pain management after TKA remains challenging and the efficacy of continuously infused intraarticular anesthetics remains a controversial topic.
  
  
  OBJECTIVE
  We compared the side effect profile, analgesic efficacy, and functional recovery between patients receiving a continuous intraarticular infusion of ropivacaine and patients receiving an epidural plus femoral nerve block (FNB) after TKA.
  
  
  METHODS
  Ninety-four patients undergoing unilateral TKA were prospectively randomized to receive a spinal-epidural analgesic infusion plus a single-injection FNB or a spinal anesthetic plus a continuous postoperative intraarticular infusion of 0.2% ropivacaine. All patients were blinded to their treatment with placebo saline catheters. Blinded coinvestigators collected data concerning side effect profiles (nausea, hypotension), analgesic efficacy (VAS pain scores, narcotic usage), and functional recovery (timed up and go test, quadriceps strength, WOMAC scores, Knee Society scores, early postoperative ambulatory ability, in-hospital falls). All complications and adverse events were recorded.
  
  
  RESULTS
  The frequency of nausea and hypertension was not different between the study groups. During the first 12 and 24 postoperative hours, the mean maximum VAS pain scores were higher in the ropivacaine group than in the epidural group (first 12 hours: 3.93 versus 1.14, respectively, p < 0.0001; 12-24 hours: 3.52 versus 1.93, respectively, p = 0.008). After 24 hours, pain scores were similar between groups. Narcotic consumption was significantly higher in the ropivacaine group on the day of surgery, but overall in-hospital narcotic usage was similar between groups. There were no clinically important differences in functional recovery between groups at any time point, but patients in the epidural group were more likely to have knee buckling (32.7% versus 6.7%, p = 0.002) and delayed ambulation (16.3% versus 0.0%, p = 0.006) than patients in the ropivacaine group, though not in-hospital falls. No infections occurred in either group, and the frequency of complications was not different between groups.
  
  
  CONCLUSIONS
  A continuous intraarticular infusion of ropivacaine can be recommended as a safe, effective alternative to epidural analgesia plus single-injection FNB after TKA. Improved analgesic efficacy in the group that received epidural analgesia plus single-injection FNB must be weighed against the disadvantage of a higher likelihood of knee buckling and delayed ambulation with that treatment approach.
  
  
  METHODS
  Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA, krr9009@gmail.com.
authors.forename: Keith R
authors.initials: KR
authors.lastname: Reinhardt
authors.forename: Shivi
authors.initials: S
authors.lastname: Duggal
authors.forename: Ben-Paul
authors.initials: BP
authors.lastname: Umunna
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Reinhardt
authors.forename: Denis
authors.initials: D
authors.lastname: Nam
authors.forename: Michael
authors.initials: M
authors.lastname: Alexiades
authors.forename: Charles N
authors.initials: CN
authors.lastname: Cornell
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D000368:Aged; D000577:Amides / Q000008:administration & dosage* / Q000009:adverse effects; D015360:Analgesia, Epidural / Q000009:adverse effects / Q000379:methods*; D000701:Analgesics, Opioid / Q000627:therapeutic use; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D004311:Double-Blind Method; D004434:Early Ambulation; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D007263:Infusions, Parenteral; D007719:Knee Joint / Q000294:innervation / Q000503:physiopathology / Q000601:surgery*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D009519:New York City; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D011446:Prospective Studies; D020127:Recovery of Function; D000077212:Ropivacaine; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000577:Amides; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D000077212:Ropivacaine