title: Imaging-guided bone biopsy for osteomyelitis: are there factors associated with positive or negative cultures?
abstract: OBJECTIVE
  The objective of our study was to identify the clinical and technical factors associated with positive or negative culture results in histologically positive cases of osteomyelitis obtained from imaging-guided bone biopsies.
  
  
  METHODS
  A retrospective review was performed of 800 consecutive patients undergoing imaging-guided core bone biopsies at two institutions. Seventy-five biopsies were performed for suspected osteomyelitis and 41 patients had histologically proven osteomyelitis. A chart review was performed to determine whether the following factors affected the culture result: histologic type of osteomyelitis, antibiotic therapy before biopsy, fever (temperature > or = 38.0 degrees C), elevated WBC count (> or = 10 x 10(3) microL), elevated erythrocyte sedimentation rate (ESR) (> or = 10 mm/h), elevated C-reactive protein value (CRP) (> or = 6 mg/L), the size of the biopsy needle, and the amount of purulent fluid obtained at biopsy.
  
  
  RESULTS
  Of the 41 cases of osteomyelitis, 14 (34%) had positive cultures. Eighteen (44%) of 41 cases were chronic osteomyelitis. Seventeen (41%) of 41 patients received antibiotics before biopsy, seven (17%) were febrile, five (12%) had an elevated WBC count, 16 (39%) had an elevated ESR, and six (15%) had an elevated CRP value. The biopsy needle size ranged from 11- to 18-gauge. These factors did not have any significant association with positive or negative culture results. Purulent fluid was aspirated in 10 (24%) of the 41 cases. In six (15%) of the cases, > or = 2 mL of purulent fluid was aspirated and five (83%) of the six cases were associated with positive culture (p = 0.02).
  
  
  CONCLUSIONS
  The rate of positive culture results in histologically proven cases of osteomyelitis obtained from imaging-guided bone biopsies is low. Aspirating > or = 2 mL of purulent fluid is associated with a significantly higher rate of positive cultures.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Shapiro 4th Fl., Boston, MA 02215, USA. jswu@bidmc.harvard.edu
authors.forename: Jim S
authors.initials: JS
authors.lastname: Wu
authors.forename: Tetyana
authors.initials: T
authors.lastname: Gorbachova
authors.forename: William B
authors.initials: WB
authors.lastname: Morrison
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Haims
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001707:Biopsy, Needle / Q000706:statistics & numerical data*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D010019:Osteomyelitis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D010414:Pennsylvania / Q000453:epidemiology; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods / Q000706:statistics & numerical data; D025321:Surgery, Computer-Assisted / Q000706:statistics & numerical data