Debilitating knee pain in a patient with "normal" radiographs

A 67 year old woman presented with a one year history of increasing pain in both knees which was worse on activity. Initial examination showed small bilateral cool knee effusions with retropatellar crepitus. Radiographs showed mild patellofemoral osteoarthritis. No other abnormality was detected in the locomotor system. Initial management comprised advice on weight and cushioned footwear, simple analgesia, quadriceps physiotherapy, and aspiration and injection of both knee joints with 40 mg triamcinolone hexacetonide. Six months later she was admitted to hospital because of severe debilitating knee pain resulting in inability to weight bear. Examination showed mild wasting of the quadriceps muscles with retropatellar crepitus and painful restriction of movement of both knees. Repeat weightbearing knee radiographs (fig 1) showed no obvious change from the initial study six months previously apart from the impression of a high density shadow in the region of both lateral femoral condyles. Further questioning showed excessive alcohol intake and an episode of alcoholic hepatitis complicating a paracetamol overdose two years previously. There was no history of oral corticosteroid treatment, diabetes mellitus, hyperlipidaemia, or recent trauma. Figure 1 Plain weightbearing knee radiographs at the time of admission, which are essentially “normal”. Biochemical investigations showed a raised γ-glutamyltransferase 115 U/l (normal 11–51 U/l) and hypoalbuminaemia …