title: Continuous intra-articular local anesthetic drug instillation versus discontinuous sciatic nerve block after total knee arthroplasty.
abstract: OBJECTIVE
  Sciatic nerve block (SNB) is commonly used as adjunct to femoralis nerve block (FNB) to achieve high-quality pain relief after total knee arthroplasty (TKA). However, this combination is associated with considerable muscle weakness, foot drop and surgically related nerve injuries may be masked. The purpose of this study was to assess whether low risk continuous intra-articular anesthetic drug instillation is an adequate alternative to SNB when adding to FNB after TKA.
  
  
  METHODS
  Retrospective investigational follow-up study.
  
  
  METHODS
  University teaching hospital. Interdisciplinary postoperative anesthetic and orthopedic survey.
  
  
  METHODS
  For this investigational analysis, 34 of 50 consecutive patients were available.
  
  
  METHODS
  All patients underwent primary unilateral TKA. Group A (18 patients) received a continuous intra-articular 0.33% ropivacaine (5 mL/h) instillation for the first 48 h postoperatively. In Group B (16 patients) a discontinuous SNB was used. Both groups were treated with a continuous FNB.
  
  
  METHODS
  Main endpoints were mean and maximum postoperative pain intensity levels for both anterior and posterior knee side, amount of postoperative administered opioid drugs, differences in functional outcome or hospital stay and rate of postoperative complications.
  
  
  RESULTS
  Group A showed higher pain intensity levels for the posterior knee side (P≤.042). Merely on the second postoperative day there were no differences within either study group. No differences were found regarding anterior knee pain. Group A showed a significant higher postoperative piritramid consumption (P≤.007). Length of hospital stay or postoperative functional outcome was not significant different. Postoperative complications were not related to anesthesia techniques.
  
  
  CONCLUSIONS
  SNB technique resulted in superior pain relief in comparison to continuous intra-articular local anesthetic drug instillation as adjunct to continuous FNB after TKA.
authors.affiliation: Department of Orthopedic Surgery, Academic Teaching Hospital Feldkirch, Medical University of Innsbruck, Carinagasse 47, A-6800 Feldkirch, Austria. Electronic address: johannes.cip@aon.at.
authors.forename: Johannes
authors.initials: J
authors.lastname: Cip
authors.affiliation: Department of Anesthesia, Academic Teaching Hospital Feldkirch, Medical University of Innsbruck, Carinagasse 47, A-6800 Feldkirch, Austria. Electronic address: hedwig.erblinzmeier@lkhf.at.
authors.forename: Hedwig
authors.initials: H
authors.lastname: Erb-Linzmeier
authors.affiliation: Department of Anesthesia, Academic Teaching Hospital Feldkirch, Medical University of Innsbruck, Carinagasse 47, A-6800 Feldkirch, Austria. Electronic address: peter.stadlbauer@lkhf.at.
authors.forename: Peter
authors.initials: P
authors.lastname: Stadlbauer
authors.affiliation: Department of Orthopedic Surgery, Academic Teaching Hospital Feldkirch, Medical University of Innsbruck, Carinagasse 47, A-6800 Feldkirch, Austria. Electronic address: christian.bach@vlkh.net.
authors.forename: Christian
authors.initials: C
authors.lastname: Bach
authors.affiliation: Department of Orthopedic Surgery, Academic Teaching Hospital Feldkirch, Medical University of Innsbruck, Carinagasse 47, A-6800 Feldkirch, Austria. Electronic address: arno.martin@lkhf.at.
authors.forename: Arno
authors.initials: A
authors.lastname: Martin
authors.affiliation: Department of Anesthesia, Academic Teaching Hospital Feldkirch, Medical University of Innsbruck, Carinagasse 47, A-6800 Feldkirch, Austria. Electronic address: reinhard.germann@lkhf.at.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Germann
mesh_terms: D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007322:Instillation, Drug; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000188:drug therapy*; D012189:Retrospective Studies; D012584:Sciatic Nerve / Q000187:drug effects*
chemical_list: D000779:Anesthetics, Local
keywords: Comparison; FNB; Intraarticular pain catheter; SNB; TKA