The 33-year-old Maeda was initially placed on the 10-day injured list Aug. 24 with right forearm tightness, but further tests revealed the severity of the injury. Texas Rangers orthopedic surgeon Keith Meister performed the operation.
Twins manager Rocco Baldelli said the procedure "went well," and there was an internal brace put in the elbow that could help speed up the rate of recovery, which is typically at least a year. The club hopes Maeda could return in nine to 12 months.
"Our goal right now is to get Kenta's rehab process going, make sure he's comfortable," Baldelli told reporters. "You really do have to take these things step by step. We'll know more as we get into the first, second, third month of this rehab process. Then, I think we'll begin to have at least more of a feel as far as how things are going."
Baldelli noted that the procedure also addressed other issues in Maeda's arm that had been bothering the veteran pitcher throughout his MLB career.
"Hopefully, when he's ready, we might see a version better than anything we've seen before, because they were able to go in there and clean some things up that he's been pitching with," Baldelli said. "This wasn't just a simple acute injury that he was dealing with.
"He's been pitching with some of this stuff for a while now. This gives him an opportunity to be at full strength going forward."
Maeda finished as the runner-up in the American League Cy Young Award voting last season. In that pandemic-shortened 2020 campaign, he posted a 6-1 record and 2.70 ERA over 11 starts.
In 21 starts this season, Maeda was 6-5 with a 4.66 ERA for the Twins.