CASE 58 INFECTED ANKLE
A 76-year-old non-insulin dependent diabetic returns to your clinic 3 weeks after ORIF of a right ankle fracture because he has been feeling unwell and has noticed redness and swelling extending beyond the plaster cast. This is a clinical photograph once the plaster cast has been removed.
- Describe this clinical picture.
This is a clinical photograph of both lower limbs. There is obvious pretibial ery- thema on the right side which has been marked out and this is suggestive of an extending cellulitis. The marked area includes the skin around the lateral malleolus. In addition, there are skin changes suggestive of chronic venous insufficiency affect- ing both legs with venous eczema and haemosiderin deposition bilaterally.
- How would you manage this patient in the outpatient clinic?
I would assess the patient fully looking particularly for signs of sepsis. I would take a history, asking specifically about any early wound problems and constitutional symptoms of infection such as fever, night sweats and loss of appetite. I would ask the nurses to perform a full set of observations. I would remove any remaining
dressings and would clean and examine the wound before applying a clean saline dressing. I would assess the vascularity of the foot using a handheld Doppler for pedal pulses. I would obtain radiographs of the ankle and would take blood samples for full blood count, inflammatory markers (CRP and ESR) and blood cultures. I would then admit the patient.
- What would be your definitive management for this patient?
This fracture will not yet have united and there is now obvious evidence of infec- tion. I would attempt to suppress the infection in the first instance using intravenous antibiotics. The success of this strategy would be dependent upon identifying the responsible bacteria and targeting them with appropriate antibiotics. If the wound has only minimal ooze or none then I would send a wound swab for microbiol- ogy examination and treat appropriately. If there is more significant drainage, any suggestion of a collection or if the patient fails to respond to initial targeted ther- apy then I would take the patient to the operating theatre, wash out and debride the wound, apply a negative pressure dressing and send samples for microbiology analysis. I would hope that this would allow the fracture to unite after which I could arrange to remove the metalwork. Repeat wound examination and renewal of the dressing will be required after 48 hours. Premature removal of the metal- work may result in an infected non-union, a much more difficult problem to treat. Nevertheless, if the infection cannot be suppressed with antibiotics, it may still be necessary to remove the metalwork.
As part of the more general management of the patient, his diabetic control should be optimised and I would recruit the assistance of the diabetic nurse spe- cialist and medical team. Attention to footwear, ulcers and pressure areas as well as the local vascularity of the foot are also important. A neurological assessment and pedal pulses should be examined for and recorded preoperatively. Doppler assess- ment should be used where pulses cannot be confidently identified.