In this article:http://es.eurosport.yahoo.com/noticias/nadal-meses-m%C3%A1s-dique-seco-095015975.html
presenta una ruptura parcial del tendón rotuliano a nivel de su inserción en el polo distal de la rótula, más una inflamación de la grasa de hoffa de la rodilla Izquierda. Desde que se le diagnostico dicha ruptura, Rafa ha estado realizando un tratamiento médico basado en medicación especifica, fisioterapia, programa de rehabilitación y potenciación muscular progresiva".
According to this text, he has more than just some "hoffa fat" on his left knee, it says he has a broken (partial) tendon (I can't translate that, I just don know what "rotuliano" means), ever since this diagnostics came out, Rafa has been undergoing a medical treatment, based on specific meds, fisiotherapy and rehab and progressive muscular "treatment".
This doesn't look good for Nadal, I always though it was just some fat on his knees, now everything is coming out on the open....
Good news "Nadal says" is that after all these months, doctors have told Nadal that the evolution has been a positive one in the last few weeks and they have been able to avoid surgery. He will continue to work just as the doctors have told him to and will be able to compete again in the near future (at least 2 and a half more months).
So, good news, he won't have any surgery, bad news, it's that it is just not some fat, and maybe will affect in the near future his development and his career.. who knows... Nadal says he will be alright and that he is sure to have many more years competing at 100% on tour. I just hope this is true, but for the looks of it, it is not going to be easy for him to return to court as soon as he hoped for.