Patient with a limp

A 50 year old man, previously well, attends his general practitioner complaining of seven days of limping and left hip pain. Examination reveals: blood pressure 150/85, pulse 110 and regular, temperature 37.9 degrees C. The left hip is irritable with decreased range of motion. The following investigations are arranged with subsequent results: full blood examination: white cell count 16 (normal 4-11) with neutrophilia C-reactive protein: elevated. Left hip X-ray (Figure 1) shows joint space narrowing, poor definition of the articular surfaces and surrounding osteoporosis.