CASE 16: PAIN IN THE KNEE
History
An 80-year-old woman presents to her general practitioner (GP) with pain and swelling in
her left knee. The pain began 2 days previously and she says that the knee is now hot,
swollen and painful on movement. In the past she has a history of mild osteoarthritis of
the hips. She has occasional heartburn and indigestion. She had a health check 6 months
previously and was told that everything was fine except for some elevation of her blood
pressure which was 172/102 mmHg and her creatinine level, which was around the upper
limit of normal. The blood pressure was checked several times over the next 4 weeks and
found to be persistently elevated and she was started on treatment with 2.5 mg ben-
drofluamethizide. The last blood pressure reading was 138/84 mmHg. There is no relevant
family history. She has never smoked and her alcohol consumption averages four units
per week. She takes occasional paracetamol for hip pain.
Examination
Her blood pressure is 142/86 mmHg. The temperature is 37.5°C and the pulse 88/min.
There is grade 2 hypertensive retinopathy. There is no other abnormality on cardiovascu-
lar or respiratory examination. In the hands there are Heberden’s nodes over the distal
interphalangeal joints.
The left knee is hot and swollen with evidence of effusion in the joint with a positive
patellar tap. There is pain on flexion beyond 90 degrees. The right knee appears normal.
NormalHaemoglobin 12.1 g/dL 11.7–15.7 g/dL
White cell count 12.4% 109 /L 3.5–11.0% 109 /L
Platelets 384 % 109 /L 150–440% 109 /L
Erythrocyte sedimentation rate (ESR) 48 mm/h !10 mm/h
Sodium 136 mmol/L 135–145 mmol/L
Potassium 3.6 mmol/L 3.5–5.0 mmol/L
Urea 7.3 mmol/L 2.5–6.7 mmol/L
Creatinine 116 &mol/L 70–120&mol/L
Glucose 10.8 mmol/L 4.0–6.0 mmol/LAn X-ray of the knees is performed and the result is shown in Fig. 16.1.