Medard went off in the second half of Les Bleus' 23-17 victory over Scotland at the weekend and a subsequent scan revealed he had suffered damaged cruciate and anterior ligaments.
The 25-year-old Toulouse player said on his official Twitter account:
"The operation is booked for Monday and my unavailability will be from six to nine months."
Medard scored a try in France's victory at Murrayfield and his absence for the remainder of the Six Nations and beyond is a significant blow to coach Philippe Saint-Andre's hopes of leading his troops to the Grand Slam.
Saint-Andre has turned to Medard's Toulouse team-mate Clement Poitrenaud to deputise at full-back for this weekend's rearranged clash with Ireland in Paris.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
