A source said doctors inserted six screws and a plate to repair the arm, which Powers broke in Sunday's loss to Dallas.
The Colts placed Powers on injured reserve Tuesday afternoon and filled his roster spot by re-signing running back Dominic Rhodes.
The Colts' other starting cornerback, Kelvin Hayden, missed last week's loss to Dallas with a neck injury. The team said he would not have practiced Monday if the Colts were on the field, but they had a day off.
They carry a three-game losing streak into Tennessee.
The Titans have lost five in a row but are expected to get receiver Kenny Britt back in the lineup after a four-game layoff with a hamstring injury.
Paul Kuharsky covers the AFC South for ESPN.com. Information from The Associated Press was used in this report.