Jack is a 59-year-old tax agent and recreational fisherman who presents with mild left lower leg pain, weakness and numbness. 

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<p>Jack is a 59-year-old tax agent and recreational fisherman who presents with mild left lower leg pain, weakness and numbness.</p><p>The symptoms began after a weekend fishing competition, during which he had been wearing a left knee brace.</p><p>He has a history of chronic left knee pain that has been treated with local steroid injections. He is otherwise well.</p><p>Jack smoke 2-3 cigarettes a day, drinks alcohol socially and has typically well-controlled hypertension and hypercholesterolaemia with candesartan and atorvastatin therapy.</p><p>On examination, his blood pressure is 150/95mmHg, with otherwise normal vital signs.</p><p>The clinical appearance of his lower limbs on presentation is pictured: the left knee is swollen and the left foot is pale and cool to touch, with absent dorsalis pedis pulse.</p>

Dr Kate Kelso is a GP and medical editor at Australian Doctor.