MRCP-0413

MRCP-0413

A 72-year-old man presents with chronic back and right hip pain which has been increasingly affecting him over the past few months. He finds it very difficult to mobilise in the mornings. Clinical examination is unremarkable, apart from a limitation of right hip flexion due to pain. Investigations show: Haemoglobin 12.1 g/dl (13.5-17.7), White cell count 8.2 x 109/l (4-11), Platelets 200 x 109/l (150-400), C reactive protein 9 nmol/l (<10), ESR 15 mm/hr (<20), Sodium 140 mmol/l (135-146), Potassium 3.9 mmol/l (3.5-5), Creatinine 92 µmol/l (79-118), Alanine aminotransferase 12 U/l (5-40), Alkaline phosphatase 724 U/l (39-117), Calcium 2.55 mmol/l (2.20-2.67). Which of the following is the most likely diagnosis?