title: Open Compared with Arthroscopic Treatment of Acute Septic Arthritis of the Native Knee.
abstract: BACKGROUND
  Acute native knee septic arthritis is a joint-threatening emergency. Operative treatments by open or arthroscopic methods are available to surgeons. To our knowledge, the literature to date has primarily consisted of case series and no large study has yet compared these methods. The aim of this study was to compare open and arthroscopic treatment for acute native knee septic arthritis.
  
  
  METHODS
  All adult patients with acute native knee septic arthritis treated at our institution with either open or arthroscopic irrigation from 2000 to 2015 were retrospectively evaluated. The clinical findings, laboratory evidence, arthrocentesis and microbiology results, knee radiographs, and outcomes were compared.
  
  
  RESULTS
  There were 161 patients (166 knees) with acute native knee septic arthritis treated between 2000 and 2015. Initially, 123 knees were treated by arthroscopic irrigation and 43 knees were treated by open irrigation; however, 71% in the open treatment group required repeat irrigation compared with 50% in the arthroscopic treatment group. The superiority of an arthroscopic procedure persisted after adjustment for potential confounders by multivariable analysis, with an odds ratio of 2.56 (95% confidence interval, 1.1 to 5.9; p = 0.027). After 3 irrigation procedures, the cumulative success rate was 97% in the arthroscopic treatment group and 83% in the open treatment group (p = 0.011). The total number of irrigation procedures required was fewer in the arthroscopic treatment group (p = 0.010). In the arthroscopic treatment group, the mean postoperative range of motion was greater (p = 0.016) and there was a trend toward a shorter median length of stay (p = 0.088).
  
  
  CONCLUSIONS
  Arthroscopic treatment for acute native knee septic arthritis was a more successful index procedure and required fewer total irrigation procedures compared with open treatment. Long-term postoperative range of motion was significantly greater following arthroscopic treatment.
  
  
  METHODS
  Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: 1The Bone and Joint Institute, Royal Newcastle Centre and John Hunter Hospital, Newcastle, Australia 2Department of Immunology and Infectious Diseases, John Hunter Hospital, Newcastle, Australia 3School of Medicine and Public Health, University of Newcastle, Newcastle, Australia.
authors.forename: Brenton P
authors.initials: BP
authors.lastname: Johns
authors.forename: Mark R
authors.initials: MR
authors.lastname: Loewenthal
authors.forename: David C
authors.initials: DC
authors.lastname: Dewar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000601:surgery*; D001182:Arthroscopy / Q000379:methods*; D003646:Debridement / Q000379:methods; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000601:surgery*; D013290:Streptococcal Infections / Q000601:surgery*; D007507:Therapeutic Irrigation / Q000379:methods*; D016896:Treatment Outcome