title: Is non-union of tibial shaft fractures due to nonculturable bacterial pathogens? A clinical investigation using PCR and culture techniques.
abstract: BACKGROUND
  Non-union continues to be one of the orthopedist's greatest challenges. Despite effective culture methods, the detection of low-grade infection in patients with non-union following tibial fracture still presents a challenge. We investigated whether "aseptic" tibial non-union can be the result of an unrecognized infection.
  
  
  METHODS
  A total of 23 patients with non-union following tibial shaft fractures without clinical signs of infection were investigated. Intraoperative biopsy samples obtained from the non-union site were examined by means of routine culture methods and by polymerase chain reaction (PCR) for the detection of 16 S ribosomal RNA (rRNA). Control subjects included 12 patients with tibial shaft fractures.
  
  
  RESULTS
  23 patients (8 women and 15 men; mean age: 47.4 years) were included into this study. Preoperative C-reactive protein levels (mean: 20.8 mg/l) and WBC counts (mean: 8,359/μl) in the study group were not significantly higher than in the control group. None of the samples of non-union routine cultures yielded microorganism growth. Bacterial isolates were found by conventional culturing methods in only 1 case of an open fracture from the control group. In this case, PCR yielded negative results. 16 S rRNA was detected in tissue specimens from 2 patients (8.7%) with non-union. The analysis of these variable species-specific sequences enabled the identification of specific microorganisms (1x Methylobacterium species, 1x Staphylococcus species). Both PCR-positive patients were culture-negative.
  
  
  CONCLUSIONS
  The combination of microbiological culture and broad-range PCR seems to substantially add to the number of microbiological diagnoses obtained and may improve the clinician's ability to tailor therapy to the individual patient's needs.
authors.affiliation: Department of Trauma and Reconstructive Surgery, University of Schleswig-Holstein, Campus Luebeck, Luebeck, 23538, Germany. justus_gille@usa.net
authors.forename: Justus
authors.initials: J
authors.lastname: Gille
authors.forename: Steffen
authors.initials: S
authors.lastname: Wallstabe
authors.forename: Arndt-Peter
authors.initials: AP
authors.lastname: Schulz
authors.forename: Andreas
authors.initials: A
authors.lastname: Paech
authors.forename: Ulf
authors.initials: U
authors.lastname: Gerlach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015373:Bacterial Typing Techniques / Q000379:methods* / Q000592:standards; D046508:Culture Techniques / Q000379:methods / Q000592:standards; D005260:Female; D005599:Fractures, Ununited / Q000000981:diagnostic imaging / Q000382:microbiology* / Q000601:surgery; D006801:Humans; D008297:Male; D020580:Methylobacterium / Q000302:isolation & purification*; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D011859:Radiography; D013210:Staphylococcus / Q000302:isolation & purification*; D013978:Tibial Fractures / Q000000981:diagnostic imaging / Q000382:microbiology* / Q000601:surgery