According to everything I've read about Hoffa syndrome, there is no treatment for it, and it goes away with rest. If you rest (real rest, not just a couple of weeks), you are fine. That's what RNadal did, took a vacation to recover from Hoffa syndrome. Only way to fix it. He's now been training for a couple of weeks, but obviously you can't regain full fitness for the US Open after such a long vacation. The week of training he had before the US Open was never going to be enough. And that's what Uncle Toni said, he said RNadal hadn't strengthened his quads in time for the US Open. He would be a fool to play the US Open when his muscles were not ready. You can easily tear a muscle if you play at the highest level after such a long break. That is what happened in 2009 when he skipped Wimbledon and then came back too quickly and tore his stomach muscle (strained it a couple of weeks before the US Open and then tore it at the US Open).
I think RNadal would be over the moon right now, because it looks like the pain he had at Miami and Wimbledon was Hoffa syndrome, and not tendinitis (and you can understand why they thought it was tendinitis originally, since Hoffa syndrome is extremely rare). RNadal has recently said he is very happy to know that his tendons are fine, and that the treatment he's been having since 2009 has worked. To know that all he's had this year is Hoffa syndrome is a great relief, because Hoffa syndrome is such a minor problem, cured by rest, and otherwise known to be cured by removing a portion of fat from behind the knee. This is actually the first year since 2007 that RNadal hasn't had a flare-up of knee tendinitis. Consider that a warning.....because RNadal will come back with a vengeance at the 2013 Australian Open, you can count on that. That essentially means he's winning the first 2 slams of 2013. Once he does that, just sit back and enjoy history being made.