The patient
This 84-year-old patient's physical health belies her age. She bounded into the surgery with her usual spritely step and launched into explaining her problem with no encouragement.
Over the previous few days, her right shoulder had become swollen and particularly uncomfortable. Paracetamol was not really helping.
It had been a ‘bit of a creaky shoulder' for some time but she had accepted the problem as one of ageing and she had soldiered on despite pain.
Clinically, there was some limitation of movement. She had no other major problem with her joints except stiffness affecting both her knees first thing in the morning. Having been ‘doctor free' for most of her life, the last year had been a stark contrast. Several months earlier, she had gone into fast atrial fibrillation, which had been stabilised. It was also felt necessary to anticoagulate her with warfarin and she was nicely settled on the drug. Her last INR was two weeks earlier, which was 2.3. She said she hadn't fallen and was keen to be rid of this nuisance swelling.
First instinct
There was clearly a tense swelling affecting the shoulder that was presumably affecting the joint. There was some discomfort with movement.
I have to admit wondering whether her memory was beginning to be a problem and that maybe she had suffered a fall and had forgotten. But she was adamant nothing had happened. She looked well otherwise and had no evidence of infection.
Differential diagnosis
• Septic arthritis
• Haemarthrosis
• Pseudogout
Septic arthritis is particularly likely to occur in people with compromised immune systems. The swelling did not look red, suggestive of infection, and although I could only go on clinical status, there was no evidence of immunosuppression and so infection seemed unlikely.
Although warfarin has undoubted benefits, its use in the elderly has to be considered carefully – particularly if they are likely to fall. She denied having had a fall and to sustain a haemarthrosis in her shoulder, she would have had to have fallen directly onto her front or shoulder and there would have been plenty of bruising elsewhere. There was none to be seen.
Pseudogout does not commonly affect the shoulder joint. But there is a rare condition called Milwaukee shoulder where hydoxyapatite crystals are found at the site of joint destruction.
Getting on the right track
I placed a needle into the swelling and removed a blood-stained fluid. The culture did not show an infection. But an X-ray showed destruction of the gleno-humeral joint. So – although rare – Milwaukee shoulder it was.
Dr Mike Wyndham is a GP in Edgware, north London
Painful, swollen shoulder
