Should both knees be replaced at once in a man in his nineties?

A man who had managed five years of knee trouble, and came in a wheelchair, wanted both done together when he saw Dr Ramneek Mahajan.

How did it start?

The patient says walking had become very hard for him. A family member says the patient could not walk properly.

Dr Mahajan says the patient arrived in a wheelchair after five years of knee problems he had managed until then, and wanted a solution.

What did this surgeon say had to be done, and why?

Dr Mahajan describes his advice. Once he had examined the patient and looked at the X-rays, he saw a knee replacement as the answer, and wondered whether a man of that age would agree. The patient wanted both knees done together, and Dr Mahajan said no: one knee at a time. The more painful side would be done first, then a gap of six weeks to two months to recover and regain strength, and the second knee only if the patient chose to come back.

What changed?

The patient says one knee was replaced. Four or five months later his right leg began to hurt, he was again advised a knee replacement, and the second knee was operated on.

Dr Mahajan says a patient's own effort matters as much as what doctors offer, and that at the patient's age what matters is being able to move.

What should an older patient with both knees affected ask?

This is one man's story, not a promise: what an operation can do for you depends on your own case.

• Ask whether both knees should be done together or one at a time, and why.

• Ask how long the gap between the two operations should be.