Stephen Strasburg is back pitching — and pitching well — for the Washington Nationals. So you might have heard people talking about something called Tommy John surgery.

Last season, Strasburg was a sensation, winning five games and throwing pitches as fast as 100 miles per hour. Then the 22-year-old hurt his elbow. Doctors decided he needed Tommy John surgery. Special doctors, called surgeons, cut into Strasburg and replaced the injured ligament in his elbow with a tendon from his thigh. (Ligaments and tendons are tissues that connect parts of the body. Ligaments link bones to bones; tendons link muscles to bones.)

Tommy John surgery is amazing stuff. The operation has helped dozens of major league pitchers with injured elbows come back and pitch. Some pitchers who have had the surgery include the New York Yankees’ A.J. Burnett, Josh Johnson of the Florida Marlins and the Nationals’ Jordan Zimmermann.

So why is it called Tommy John surgery rather than, say, Frank Jobe surgery?

Frank Jobe is the surgeon who invented this ligament replacement surgery in 1974. The first patient on whom he tried it was a baseball player named Tommy John.

John was a very good left-handed pitcher for the Cleveland Indians, Chicago White Sox and Los Angeles Dodgers from 1963 to 1974. During the 1974 season, John hurt his elbow so badly he couldn’t pitch. Many people thought the injury would end his baseball career.

But John went to Jobe, who decided to try an experimental surgery. John figured he didn’t have anything to lose, since the surgery was his only chance of pitching again. Jobe replaced John’s injured ligament with a tendon from a cadaver. (That’s a body that has been donated to medicine.)

The surgery worked. After a year of special exercises to slowly strengthen his arm, John was ready to pitch. He pitched 14 more seasons after the surgery, winning 162 more games.

Since 1974, doctors have changed some of the procedures they use to improve the chances for pitchers to recover from Tommy John surgery. For example, they now take the tendon from the patient, not a cadaver. Doctors are like athletes; they usually get better the more they practice.

So far, Strasburg has looked good pitching for the Nats, giving up only two runs in 14 innings. He worked hard to come back, and now baseball fans hope he can become the star they thought he would be.

If he does, Strasburg can thank his surgeon, Lewis Yocum. But he can also thank Frank Jobe and Tommy John, a baseball player who loved the game so much he would try anything to pitch again.

Fred Bowen is the author of 17 sports books for kids, including eight books about baseball. His latest baseball book is “Throwing Heat.”