Knee specialist Dr. Raju Vaishya has successfully operated the oldest couple, Shri S.N. Bhatt (93 years) and his wife Vijaylaxmi (86 years), of Chhattisgarh, Madhya Pradesh. The duo had undergone bilateral knee replacement in a single sitting, at Apollo Hospital, New Delhi. While Mr. Bhatt underwent surgery in April 2011, his wife was successfully operated upon November 2011.