Organisms that commonly infect prosthetic joints are also the same organisms that live on the skin, namely organisms such as coagulase negative staphylococci, propionibacteria, corynebacteria, etc. Such skin organisms are the commonest causes of contamination of orthopaedic tissues, especially true when using the prolonged enrichment broths which are required in order to recover low organism numbers, antibiotic affected organisms and organisms that may be in a biofilm on infected prosthetic joints. Therefore in order to ensure that you recover the responsible organism(s) and at the same time minimise the risk of contamination various important steps need to be taken:

  • Minimum of 5 samples examined for each first and second stage examined, based upon the excellent work by Bridget Atkins (1998 Journal Clinical Microbiology)
  • Pre-operative/diagnostic aspirates and/or biopsies to identify causative organism(s) prior to revision
  • Samples processed under laminar flow/class II safety cabinet to minimise specimen contamination (not available in many laboratories)
  • Samples processed in accordance with national standard operating procedures
  • Prolonged enrichment broths (a minimum of 7 days) to enable optimum isolation of causative organisms
  • Terminal subculture of diagnostic aspirates and all first and second stage broths to ensure testing recovery of organisms such as propionibacteria
  • Sensitivity testing of antibiotics relevant to those used in prosthetic  joint infections including those used in bone cements (eg vancomycin, gentamicin, meropenem, aztreonam, colistin, daptomycin, voriconazole).

Sample transport can be user determined; for routine samples UKOMS will provide the ‘Safebox’ option which allows samples to be delivered by Royal Mail on a next day basis.  Alternatively, after discussion with the UKOMS team, urgent samples can be sent using an express courier.

All samples will processed by trained staff in accordance with national agreed SOP’s under laminar flow conditions, all of which are designed to optimise recovery of causative organisms whilst minimising the risk of laboratory contamination.

The specifically designed report template creates an orthopaedic samples friendly final report and allows the user to visualise all the samples processed on one report.  This report can be emailed, posted and/or faxed (provided proof of a safe-haven fax) dependent on user preference.