Photo: AFL Media.

North Melbourne defender Nathan Grima has announced his immediate retirement due to ongoing back problems.

The 29-year-old had a setback in his most recent recovery from back surgery and received advice from specialists to undergo another operation to fuse a disc in his spine. The surgery, which hopefully alleviated his current pain and symptoms, is Grima’s third back operation.

Grima played 86 games with the Kangaroos after being taken with the No. 14 pick in the 2008 Rookie Draft.