A recent history of Tommy John surgery

Luis Severino, Chris Sale, Noah Syndergaard. Three giants in the grove of baseball’s pitching elite, felled by the indiscriminate equalizer that is Tommy John surgery (TJS). It seems like more than ever, the game’s biggest stars are succumbing to this common enemy of pitchers. What is driving this epidemic?

Tommy John surgery, or more scientifically ulnar collateral ligament (UCL) reconstruction surgery, was invented in 1974 by Dodger’s team physician and orthopedic surgeon Frank Jobe. It is named after the first pitcher to receive the treatment, Tommy John. The surgery involves securing the elbow by threading a graft through holes drilled in the ulna and humerus. The graft tissue is commonly harvested from tendons in the non-afflicted arm, the hamstring, or the big toe.

A recent study showed that around 80% of first-time TJS pitchers return to pitch at similar pre-injury levels. However, only around 65% of pitchers who undergo revision surgery (essentially a second TJS) return to the majors, and go on to pitch for fewer seasons on average and with diminished performance relative to controls. Return timetables for TJS rehabilitation range anywhere from 12 to 30 months, depending on factors including nerve damage and surgery complications. Players who successfully return from the surgery go on to play for about four more years on average.

The Yankees are no strangers to Tommy John surgery. In the last five years, the list of Bombers past and present who have undergone the procedure include Didi Gregorius, Aaron Hicks, Gleyber Torres, Jordan Montgomery, Jonathan Loaisiga, Domingo German, Nathan Eovaldi, Clarke Schmidt, Michael Pineda and Ben Heller.

While it is still a pitcher-dominant affliction, Tommy John surgery has also claimed the seasons of some prominent position players in recent seasons. In addition to the aforementioned Gregorius and Hicks, Salvador Perez, Pablo Sandoval, Travis d’Arnaud and Corey Seager have missed or will miss significant time while recovering from the procedure.

With Severino, Sale and Syndergaard all getting surgery so close together, I wondered if this was part of a larger trend. Are pitchers suffering UCL damage more frequently? If so, what factors may be contributing to this?

Some studies have suggested that throwing a breaking ball is more harmful to a pitcher’s arm than a fastball or offspeed pitch. The dangers of supinated pitches are well known, and are why the slider and curveball and generally the last pitches taught at the Little League level. In fact, some regions in Little League have regulations concerning the age at which breaking balls may be implemented.

If the breaking ball is the culprit behind TJS susceptibility, I wondered if recent developments have heightened this. The advent of the Statcast era allows pitchers to extract every ounce of potential out of their offerings. Pitch tracking devices such as Trackman and Rapsodo give pitchers such precise and granular information that they are able to make the minutest tweaks to their hand positioning and throwing motion. The analytics departments parse these mountains of data to optimize performance on the field, and the results are quite visible.

The consensus seems to be that a pitcher is more successful when he throws a slider faster, more often, and with greater spin. There has been a drastic increase in slider rate from 2014 (13.7%) to 2019 (18.4%). The league average slider spin rate has increased from 2015 (2106 RPM) to 2019 (2428 RPM). Pitchers are also throwing harder than ever. Whereas in 2002 the average slider velocity was 80.4 MPH, in 2019 the average velocity at at 84.6 MPH. This pursuit of velocity is putting a tremendous amount of torque on arm ligaments.

Made The Cut/YouTube

Yes, that is a 93 mile per hour slider with as much tilt as 2004 Brad Lidge. This is a feat that does not seem humanly possible. And to that point perhaps the human body is being pushed beyond its limits having to withstand such extraordinary forces.

Is the confluence of these pitch tracking devices and the maximization of velocity and spin rate on breaking balls causing pitchers’ UCL’s to become more compromised? The reality surprised me. Since the beginning of pitch data aggregation, TJS rates have remained relatively stable. There is no appreciable difference between the pre-Statcast era of 2002-2015, where on average 22 surgeries were performed per year, versus the Statcast era of 2015-present, during which there were 23 surgeries per year on average.

If Tommy John surgery is not happening with greater frequency, why does it still feel like it is more common than ever? I chalk this up to recency bias. It is easier to recall the more recent cases, especially when they include household names like Sevy, Sale and Thor in such rapid succession. I’d wager not many people could name offhand any players from the early 2000’s who underwent the procedure.

It sucks that we will be without three of baseball’s premier pitchers, who turn pitching into an art that is a wonder to behold. Perhaps it is best that they chose this avenue during a season with so much uncertainty. We can only hope that they will be healthy and as good as ever come 2021.