Olly Murs has told how his fiancée Amelia Tank nursed him back to health after career-threatening knee surgery left him unable to walk for 12 weeks.The Voice coach, 38, was rushed to hospital in February following a terrifying accident onstage that caused a fragment of bone to wedge into the back of the knee.The injury couldn’t have come at a worse time with Olly's romantic plans to propose to bodybuilder Amelia, 30, at the top of a Cornish cliff in June. Opening up about the operation to replace a torn ligament, he said: “I couldn’t walk. For 12 weeks I was sat in a chair staring at four f***ing walls with crutches and Amelia having to help me to the toilet and get me in the shower.