Enchondroma is a benign tumour of bone that is common in the small bones of the hand. The tumour is composed of cartilage cells. It can expand to the point where the host bone is thin and can even fracture. They can be treated with surgery to remove the tumour and Dr Kirkham likes to replace with (autogenous cancellous) bone graft. Your own bone taken from the back of your wrist – that is a very safe and minimally invasive technique.