While not a Hall of Famer, Tommy John had an extraordinary baseball career. Pitching mostly for the Yankees, Dodgers, White Sox and Angels over 26 seasons, he threw more than 4,700 innings, stuck out 2,245 batters and won 288 games. While baseball fans might remember his career achievements, most people probably know the name Tommy John for something other than his time on the field: a surgical procedure that now bears his name.
In 1974 while pitching for the Dodgers, John tore the ulnar collateral ligament (UCL) in his left pitching elbow. At the time it seemed as though he would never pitch again, since this was considered a career-ending injury at the time. But Frank Jobe, an orthopedic surgeon working with the Dodgers, pioneered a new surgical procedure to reconstruct the UCL by replacing it with a tendon from John’s other forearm.
After spending the entire next season rehabilitating his arm, John went on to pitch 14 more seasons, amassing more than half of his career win total after the injury. The surgery—now known to sports fans as “Tommy John surgery”—has been perfected over the years and is now common practice for athletes who rupture the UCL. In 2013 the National Baseball Hall of Fame honored Jobe for his contribution to the sport (Update: Two days after this story was published, Dr. Jobe died at the age of 88).
UCL reconstruction is clearly an effective option for helping pitchers recover from what had been a career-ending injury. A number of studies have shown that between 73 to 94 percent of pitchers are able to return to preinjury levels of performance in common statistical measures like earned run average (ERA), walks and hits per inning pitched (WHIP) and strikeout to walk ratios. But are they the same players after Tommy John surgery, or did they adapt their approach to protect a surgically repaired elbow? Do power pitchers who relied on 100-mph fastballs to overwhelm hitters turn into crafty veterans painting the corners with off-speed pitches?
In a study published recently in the American Journal of Sports Medicine, University of Chicago orthopedic surgeon Martin Leland (@DrMartinLeland) and resident Jimmy Jiang analyzed a trove of pitching data from Major League Baseball and found no significant difference in pitch velocity between players who underwent Tommy John surgery after a UCL injury and those who were never injured during the same time period.
The study is the first to look specifically at pitch velocity after UCL reconstruction, suggesting that the procedure not only helps pitchers recover their pre-injury performance levels, but also their physical abilities as well.Jiang, a lifelong baseball fan, says he thought of the study as a way to apply his medical knowledge to the growing field of statistical analysis in baseball. The UCL is the main stabilizer in the elbow during the pitching motion. When a pitcher brings his arm forward in the acceleration phase of the throwing motion, the hand lags behind the elbow as it rotates over the top. This motion puts a lot of what’s called “valgus stress” on the elbow. Over a career of thousands of pitches that stress adds up, leading to weakness and damage in the ligament.
“The theory is that these high performance athletes who throw in the upper 80s or 90s accumulate microscopic damage to the ligament over time through the high number of repetition of pitches. At some point, the combined stresses overwhelm the UCL, causing it to rupture,” Jiang said.
Jiang and Leland used official league injury reports to identify 41 major league pitchers who underwent UCL reconstruction from 2008-2010. Then, using data from PITCHf/x, a service used by Major League Baseball to track every pitch during each official game, they analyzed pitching performance for one year prior to the injury and at least 2 years after they returned to baseball. The data included average pitch velocity for fastballs, changeups, curveballs and sliders (if those pitches were part of the players’ repertoires—sorry, no knuckleballs). They also studied common performance statistics including total innings pitched, ERA, WHIP, batting average against, walks per 9 innings and strikeouts per 9 innings.
Each injured pitcher was matched with an uninjured pitcher (as a control) with the most similar career statistics prior to the season of injury. When Jiang and Leland compared each of these matched pairs, they saw no significant differences in pitch velocity or any of the performance measurements between players who had UCL surgery and those who didn’t. They did see a slight decrease in pitch velocity over time that was similar in magnitude for both groups of players. This means that all pitchers—injured or not—lose a little zip on their fastball as they age and compile the stress on their arm from the large number of pitches thrown each season.
Does this mean Tommy John surgery is a miracle cure for pitchers who blow out an elbow? Not quite. Twenty one percent of the players studied didn’t return to the majors after UCL reconstruction, and it took an average of 17 months for the ones who did recover to pitch again. But according to this study, if a pitcher does make it all the way back to the big leagues, he’s going to be almost as good as new.
“UCL reconstruction is a very effective surgery, but it’s also a pure testament to the level of dedication and focus of these athletes that 80 percent of them make it back to the highest level of play,” Leland said. “They’re determined that they will get back to playing just as well as before. They work extremely hard, and they’ll be able to get there.”
Jiang J.J. & Leland J.M. Analysis of Pitching Velocity in Major League Baseball Players Before and After Ulnar Collateral Ligament Reconstruction, The American Journal of Sports Medicine, DOI: 10.1177/0363546513519072