A 75 year old gentleman presents with a long standing history of back pain. He struggles to walk more than a 100metres without needing to sit down as he reports his legs start to feel like jelly. Sitting down only makes his back pain worse.

• What would you watch out for on examination?

He goes on to have an MRI scan of the lumbar spine and a sagittal and axial view are shown below.

• What can you see?