My S-i-L is on his third set of hip replacements. (Osteoarthritis necessitated the first set, he wore those out and was then given the deadly Johnson and Johnson "last a lifetime" version that leaked heavy metals into his bloodstream) 18 months after the last op he was still in pain, but scans showed that nothing appeared wrong. DD persuaded him to join her at her yoga class, and when he went for a check up 6 months later, he was happy to report that he was pain free. He was told by the surgeon to carry on with the yoga, but not to sit cross-legged on the floor, to put his feet together and let his knees flop out, but he is now able to sit with his legs crossed.