Pintrack infections

Pin site infections are the most common complication of external fixation treatment

• as a 'foreign body' the pin acts as a focus for infection. Infection begins superficially, before spreading to the deep soft tissues, and eventually bone if left untreated
• early identification and treatment of pin site infections is therefore essential

Clinical features

• erythema and tenderness around the pin in an area that was previously not tender
• white, yellow or green cloudy discharge from the pin site (drainage of serous fluid often represents swelling and inflammation rather than infection, frank red blood discharging from a pin site usually represents minor tearing of muscle or skin often resulting from aggressive physiotherapy rather than infection)
• pin loosening
• fever and malaise are late features

General pin site care

• aims to keep the interface between pin and skin free from bacteria and to prevent trauma to the skin
• cleaning and dressing around the pin is usually done weekly and increased to daily if there are signs of inflammation

When to treat and when to refer?

• Management in Primary Care
  • increase the frequency of pin site care by patient (often require daily pin site care)
  • swab affected areas (around 85% are due to Staph infections. These are largely staph aureus, and staph epidermidis)
  • oral antibiotics are often required to suppress the infection, although eradication is only achieved when the external fixator is removed (patients may be provided with a supply of antibiotics to start when they suspect a pin site infection without having to consult their GP)
• Referral Criteria
  • infection not responding to oral antibiotics
  • development of an abscess around a wire or pin.
  • clinical or radiological suspicion of osteomyelitis
  • removal of pin required
  • patient systemically unwell (rare). Inpatient treatment may consist of IV antibiotics or surgical drainage.

Contributors (June 2010):

• Andrew D Murray
  • GP Registrar Teviot Medical Practice, Hawick, Scottish Borders, UK
• Iain R Murray
  • Specialty Registrar Edinburgh Orthopaedic Trauma Unit, UK
• Gary Keenan
  • Consultant Orthopaedic Surgeon Edinburgh Orthopaedic Trauma Unit, UK