Frank et al reported a definition for pin site infection (PSI).
The authors are from Oxford University Hospitals and University Hospital Basel.
Patient selection: external fixators, skeletal traction, or transcutaneous fixation pins
Confirmatory criteria:
(1) skin breakdown with visible bone
(2) painful, purulent drainage from the pin
(3) ring sequestrum on plain X-rays under a wet pin site (persistent or increasing drainage of fluid)
(4) progressive bone lysis around a pin under a wet pin site
(5) aspiration of subcutaneous fluid collection around the pin with positive microbiological culture with a virulent organism
(6) aspirate from effusion of a joint in close proximity to an external fixation demonstrating a virulent organism (septic arthritis)
Common virulent organisms include:
(1) Staphylococcus aureus or lugdunensis
(2) beta-hemolytic streptococci
(3) Streptococcus anginosus group
(4) Enterococcus species
(5) Enterobacteriaceae
(6) Pseudomonas aeruginosa
(7) anaerobic Gram-negative bacteria
(8) Candida albicans
Suggestive criteria:
(1) local pain, especially if of new onset
(2) wet pin site
(3) spreading erythema
(4) pin loosening
(5) fever or pyrexia without other cause
(6) other systemic upset
(7) new onset of joint effusion adjacent to pins or wires
(8) lysis around pins or wires
(9) subcutaneous fluid collection in keeping with a possible abscess
(10) radiological signs of sequestrum under a dry pin
(11) rising serum inflammatory markers (WBC count, CRP) in the absence of other causes
where:
• An additional suggestive criterion was added for ring sequestrum or progressive bone lysis with a dry pin.
An infection is unlikely if the pin site is clean and dry, without pain or erythema.
