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