"I am out of surgery and healing steadily, for which I thank my doctors, family, friends, and everyone who has wished me good health and speedy recovery," the left-handed batsman posted on Twitter and Instagram on Saturday.
"The issue began way back. It was 2007 when I underwent my maiden knee surgery and later, I was back on the field, giving the game my 100 per cent, all thanks to my trainers and doctors.
"However, a nagging discomfort returned last couple of years. During the episodes of niggling pain, to avoid any impact on my game, my trainers kept me going and helped me a lot in training my muscles well so that it would take the load off of the knee.
"To be honest, a second knee surgery was a tough call to make because I knew it would put me off-action for a few months and I wasn't ready for it until a few weeks ago when the pain had gotten a bit much and I knew there was only one way out of this.
"I hope I'm up on my feet, on the field and ready to give my best very soon again," he added.
The left-handed batsman will not be available for most part of India's upcoming domestic season which begins with Duleep Trophy.
The 32-year-old southpaw last played for India in an ODI against England in 2018. Raina, a World Cup winner in 2011, has played 18 Tests, 226 ODIs and 78 T20Is. He was last involved in the Indian Premier League (IPL) with Chennai Super Kings.