title: The fate of acutely inflamed joints with a negative synovial fluid culture.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the management and fate of acutely inflamed joints with a negative synovial fluid culture.
  
  
  METHODS
  Between January and December 2009, all the patients who presented to our institution with an acutely inflamed joint and were subjected to microbiological assessment of their synovial fluid, were included in the study. Patients with a positive synovial fluid culture, a prosthetic joint replacement in situ and where an aspirate was obtained for a rheumatological diagnosis were excluded. This cohort was then divided into two groups depending on whether a diagnosis could be established through the course of their treatment. Group I included patients in whom a diagnosis could be established and group II included patients in whom a diagnosis could not be established. A thorough review of the patients' medical records and the hospital database was performed. Following this, a database consisting of the patient demographics, clinical features, investigations, treatment and outcome was created.
  
  
  RESULTS
  A total of 144 patients met the inclusion criteria (group I: 95, group II: 49). The most commonly affected joint in both the groups was the knee. The average time to presentation was shorter in group II. Clinical findings at presentation were comparable in both groups. However, inflammatory markers were more likely to be raised in group II in comparison with group I. Eighty-two percent of group II required antibiotic treatment compared with 15% of group I. The mean duration of antibiotic treatment in group I was ten days and in group II was 26 days. Mean hospital stay differed significantly between the two groups, with group II being more than twice as long as compared with group I (p=0.001). The rate of mortality was also higher in group II (8.2%, p=0.03).
  
  
  CONCLUSIONS
  Our study shows that patients presenting with an acutely inflamed joint and a negative synovial fluid culture in whom a diagnosis cannot be established during their hospital stay have a longer hospital stay and an increased rate of mortality as compared with patients in whom a diagnosis can be established.
authors.affiliation: Department of Trauma and Orthopaedics, Addenbrooke's-Cambridge University Hospital NHS Foundation Trust, Box 37, Hills Road, Cambridge, CB2 0QQ, UK.
authors.forename: Ihab
authors.initials: I
authors.lastname: Hujazi
authors.forename: David
authors.initials: D
authors.lastname: Oni
authors.forename: Arvind
authors.initials: A
authors.lastname: Arora
authors.forename: Garciela
authors.initials: G
authors.lastname: Muniz
authors.forename: Vikas
authors.initials: V
authors.lastname: Khanduja
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001168:Arthritis / Q000175:diagnosis* / Q000382:microbiology* / Q000401:mortality / Q000628:therapy; D001772:Blood Cell Count; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007596:Joints / Q000382:microbiology* / Q000473:pathology*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D026741:Physical Therapy Modalities; D015996:Survival Rate; D013582:Synovial Fluid / Q000166:cytology / Q000382:microbiology*; D007507:Therapeutic Irrigation / Q000379:methods; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents