Snapshot diagnosis - what's wrong with this diabetes patient?

GP Dr Mike Wyndham shares another uncommon diagnosis in a case involving one of his patients.

The patient

This 68-year-old man had diabetes, which had been under variable control over the years. He had been on renal dialysis for two years and seven years prior to this it was noted that he had a neuropathy with a small ulcer developing on his big toe without him realising.

The patient came to see me on this occasion because his ankle had swollen and was now becoming deformed. A wound had developed on the ankle and was discharging.

First instinct

Possibly an osteomyelitis.

Differential diagnosis

Charcot arthropathy was a definite possibility as the patient had diabetes and had developed a neuropathy. The arthropathy is more common in those receiving dialysis. Other causes include: chronic alcoholism, leprosy, spinal cord injury.

The clues

The biggest clue was found on examination of the ankle. It seemed as if the joint was not connected together at all, confirming charcot arthropathy.

Outcome and treatment

The orthopaedic surgeons felt it was not possible to do anything surgically. Despite being unable to walk on this leg, the patient refused an amputation.

Dr Mike Wyndham is a GP in north London