Richards didn't specify an expected return date, saying only, "he's going to be out over an extended period of time," The Columbus Dispatch reported.
The blueliner suffered the broken bone during Sunday's 1-0 loss to Chicago.
He joins fellow defenseman Jack Johnson (right shoulder) on the Blue Jackets' injured list. Richards said Johnson is expected to begin skating next week.
Wisniewski has compiled three goals and six assists in 15 games this season.