Rome  - AC Milan defender Kakha Kaladze is out for the remainder of the Serie A season after undergoing knee surgery in Belgium.

The club's web site Tuesday wrote that the 31-year-old Georgian was successfully operated on his right knee in Antwerp by doctor Marc Martens. His recovery is estimated in about five months.

Kaladze is at Milan since 2001. He joins an injured list already including long-time absentees Alessandro Nesta and Gennaro Gattuso, two mainstays in defence and midfield, respectively, who are unlikely to be available before the season ends in late May. (dpa)