MotoGP: Casey Stoner undergoes surgery on broken ankle

Casey Stoner has undergone surgery on the broken ankle he sustained in qualifying at Indianapolis.

The Australian world champion has already returned home following the operation at the North Sydney Hospital.

The 26-year-old said on Twitter: "Operation went as well as can be expected, all the staff were great also."

Stoner, who will retire at the end of the season, added: "Now we just have to wait and see how I recover."

The Honda rider finished fourth in Indianapolis despite suffering torn ligaments, bone damage and fractures to his ankle in the crash in qualifying. He was advised by doctors to have the surgery to prevent permanent damage.

"Doctors are pleased with how the operation went, and now must wait during this initial recuperation period to see how the ankle is healing," Stoner's Honda team announced.

Stoner is currently third in the standings, 59 points behind leader Jorge Lorenzo, with six races of the season remaining.

He hopes to return one or two races before his home GP at Phillip Island on 28 October.