Ace India shuttler Saina Nehwal on Saturday underwent a knee surgery at a hospital in Mumbai after suffering the injury early this month, which got aggravated during the Rio Olympics. Dr Dinshaw Pardiwala, Head of Centre for Sports Medicine, Director Arthroscopy and Shoulder Service at the Kokilaben Dhirubhai Ambani Hospital said that Saina Nehwal has sustained an intra-articular injury to her right knee. A small fragment of bone has separated from her knee cap bone. He added that this displaced fragment is causing her impingement and pain. Saina has undergone arthroscopic surgery this morning and is back in her room.