Macri injured himself Monday while playing paddle tennis, according to his office which said a small piece of his torn meniscus had to be removed.
"He's perfectly fine," his spokesman Ivan Pavlovsky spokesman told reporters after the procedure was completed yesterday.
It was the second time in less than a month that the Argentine leader had to be hospitalised.
A few weeks ago, he was admitted to the hospital suffering from an irregular heart beat, but was released several hours later after being observed by doctors.