Power tools at the ready! The life-changing science behind hip and knee replacements

Thousands of people are given new joints each year in the UK. But can robots and smart tech soon make it a smoother procedure?

Ian Doncaster is remarkably chipper for a man about to undergo major surgery. I have a busy life. So it's nice to have a break," he jokes. It is 8.30am on a chilly December morning and here at Warwick hospital he is about to receive a new knee - or part of one.

At 62, Doncaster has always been active: he played rugby when young, until a knee injury and subsequent operation meant he had to trade that in for a host of other sports. But now the knee is causing problems again. As a self-employed chartered engineer, he needs to be able to get up and down tower blocks. Even going hiking with his wife seems a wistful dream. Going forward, it's only going to get worse," he says.