Kimiko Date-Krumm may have to make a career-ending decision after surgery revealed the 45-year-old's left knee is in worse shape than expected.

The former world No. 4 wrote in a blog entry on Sunday that she had arthroscopic surgery last week to clean out the knee, but the procedure found the meniscus to be badly worn out.

Date-Krumm, who initially retired in 1996 before making a comeback in 2008 at the age of 37, said she has been told by her doctor that it will be difficult for her to return to the court and that she would need additional surgery if she wanted to continue to play.

"As an athlete, it will be beyond tough to live life without taking part in sport," Date-Krumm said. "If I decide to have surgery again, it's unavoidable that it will take a long time for me to come back.

"I want to think long and hard before deciding on the best possible option."