gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2016)

25.10. - 28.10.2016, Berlin

The role of microcalorimetry and PCR of joint aspirate for early diagnosis of septic arthritis

Meeting Abstract

  • presenting/speaker Christian Morgenstern - Charité Universitätsmedizin Berlin, CMSC, Berlin, Germany
  • Sabrina Cabric - Charité Universitätsmedizin Berlin, CMSC, Berlin, Germany
  • Anne-Katrin Fietz - Charité Universitätsmedizin Berlin, CMSC, Berlin, Germany
  • Elena Maryka Maiolo - Charité Universitätsmedizin Berlin, CMSC, Berlin, Germany
  • Andrej Trampuz - Charité - Universitätsmedizin Berlin, Centrum für Muskuloskeletale Chirurgie, Centrum für Septische Chirurgie, Berlin, Germany
  • Carsten-Frank Perka - Charité - Universitätsmedizin Berlin, Centrum für Muskuloskeletale Chirurgie, Berlin, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2016). Berlin, 25.-28.10.2016. Düsseldorf: German Medical Science GMS Publishing House; 2016. DocWI32-53

doi: 10.3205/16dkou195, urn:nbn:de:0183-16dkou1956

Veröffentlicht: 10. Oktober 2016

© 2016 Morgenstern et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: Septic arthritis is a medical emergency that requires immediate diagnosis and treatment. Current diagnostic methods are time-consuming and have limited sensitivity. Polymerase chain reaction (PCR) is a non-culture-based, molecular method for detection of microbial DNA. Microcalorimetry is a detection method of microbial growth-related heat production. Aim of this study was to evaluate microcalorimetry and a novel fully automated multiplex PCR for early detection of septic arthritis and compare them to current diagnostic standards.

Methods: In this prospective study, joint aspirates were pre-operatively obtained for patients with suspected acute arthritis of the hip or knee from October 2014 to September 2015 at our institution. In addition to standard culture, joint aspirates were analyzed by multiplex PCR (Unyvero, Curetis) and microcalorimetry (TA Instruments). Septic arthritis was diagnosed if the joint aspirate culture was positive OR if the following 3 criteria were present: (i) typical local inflammatory signs and symptoms, (ii) abnormal aspirate fluid leukocyte count (> 20.000 leukocytes/ul) or differential (> 90% granulocytes) and (iii) exclusion of other potential causes of arthritis (i.e. rheumatoid pathology). Sensitivity and specificity of each test were determined and significance was evaluated with McNemar's Chi squared test or binomial test as appropriate.

Results and Conclusion: 55 patients with acute arthritis were included (48 knee and 7 hip joints). The median age (range) was 60 (20 - 85) years; 29 (53%) were males. 27 (49%) patients were diagnosed with septic arthritics and 28 (51%) with aseptic pathology (Table 1). Sensitivity of culture, microcalorimetry and PCR were similar: 33%, 37% and 22%, respectively (p < 0.05). PCR detected following microorganisms: coagulase-negative staphylococci (n=2), S. aureus (n=2), streptococci (n=3), Propionibacterium acnes (n=2) and others (n=2). Compared to joint aspirate culture, PCR failed to detect S. aureus (n=2), streptococci (n = 1) and gram-negative rod (n = 1). The processing time for PCR was 5 hours, median detection time for microcalorimetry was 9 hours (range, 2.3 - 64 hours) and for cultures 48 hours (range 1 - 14 days).

The sensitivity of microcalorimetry and multiplex PCR of joint aspirate were similar to the one of joint aspirate culture, while specificity of calorimetry (96%) and PCR (82%) was high. PCR and calorimetry provided rapid results (within 5 hours and median of 9 hours, respectively), while PCR delivered antimicrobial susceptibility also from non-viable bacteria. With improved sensitivity, microcalorimetry and multiplex PCR may replace cultures of joint aspirates and enables more rapid pre-operative diagnosis of septic arthritis.