It was initially suggested that Lamont had broken his leg but Scotland team doctor James Robson revealing that the injury is indeed a fracture to his fibula.
Lamont has started every one of Scotland's RBS 6 Nations games so far - all three ending in defeat with England winning 13-6, Wales 27-13 and France most recently 23-17 at Murrayfield on Sunday.
Coach Robinson admitted Lamont's withdrawal did have an effect on Scotland in their clash with France with team doctor Robson set to reveal further news on his injury in due course.
He said: "Rory is under the care of the orthopaedic surgeons at Edinburgh Royal Infirmary. We will issue a further bulletin tomorrow following this surgery."
Robinson's injury problems don't end there with Rory's brother Sean suffering an abrasion to his right eye and centre Graeme Morrison requiring further assessment for a knee injury.
Mike Blair is confirmed as having a dead leg as do Richie Gray and John Barclay while Greig Laidlaw appears to have suffered a concussion and Jim Hamilton has leg bruising.
Scotland have a scheduled rest weekend now before travelling to Dublin for the penultimate game of the 2012 RBS 6 Nations clash with Ireland on March 10.