Pastornicky suffered the injury colliding into Jason Heyward on Wednesday night. The surgery will take place on Monday, and no timetable for a recovery has been announced.
Atlanta promoted Pastornicky on Tuesday when Dan Uggla went on the disabled list after undergoing LASIK surgery. The Braves planned to have Pastornicky serve as the team's everyday second baseman until Uggla is eligible to return on Aug. 28.
The club purchased the contract of Phil Gosselin from Triple-A Gwinnett to replace Pastornicky on the 25-man roster. Gosselin batted .277/.326/.343 in 47 games for Gwinnett this year after receiving a midseason promotion from Double-A.
Either Gosselin or Paul Janish could start at second until Uggla returns. Janish is considered an excellent defender, but is a career .214/.284/.288 hitter. Janish's limited offensive ability has lead the Braves to search for a second baseman on the waiver wire, reports Mark Bowman of MLB.com