An Analysis of Available Tommy John Surgery Data

Jordan Zimmermann is one of the recent Tommy John survivors to thrive. (via Cathy T)

Jordan Zimmermann is one of the recent Tommy John survivors to thrive. (via Cathy T)

With both the caliber and frequency of players heading for ulnar collateral ligament reconstruction surgery in 2014, Tommy John surgery has been a popular topic in the media this year. The Hardball Times’ Jeff Zimmerman summarized the most recent research in a twopart series on the surgery not long ago. The articles noted at least a dozen examples of Tommy John surgery stories from the mainstream media, with many more going unmentioned.

Despite the flood of information on the topic, there are some interesting ways of looking at Tommy John surgeries that have not been fully explored to this point. As I have recently added additional details to the list of professional baseball surgeries I maintain, here are some new angles that can now be illuminated further.

Recovery Times and Success Rates

Before these related issues can be examined, it is important to define what it means for a player returning from Tommy John surgery to have “recovered.” Does playing at any professional level of baseball suffice? Does a player have to return to play in the same league he was playing in when the surgery became necessary? Is there some minimum number of innings pitched required to be seemed recovered? Should performance be considered in any way? This is a complicated problem, and one that I would suggest does not have one correct answer.

For the purposes of the Tommy John surgery list I maintain, I decided that a player had to return to play at the same level of baseball as before the surgery. In other words, a major league player is  considered “recovered” from Tommy John surgery only once he re-enters a major league game. Simply starting a rehab assignment is not good enough. A minor league baseball player is deemed “recovered” by returning to minor league action.

There are a couple of ways I wanted to analyze surgery return times that I have not seen done. The first involves tracking recovery times by era, to determine whether overall recoveries are happening faster and with better success rates over time.

An additional wrinkle is that the expected return time varies quite a bit depending on the time of year the procedure takes place. Pitchers who undergo surgery in spring training or April would be expected under any sort of normal rehabilitation process to be able to return at some point during the following season. Those who go under the knife in September or the offseason have, at best, a narrow window of a recovery path that would allow them to play in any of the next season. Once a player does not return by September, it automatically tacks on at least another six months to his recovery time until regular season games begin the following April.

For this reason, along with looking at overall numbers over the years, I have broken down the average return time by quarter as well. I’ve included numbers for the two most common quarters where surgeries occur – the two that overlap with the baseball season. I hope that including these will allow for a more worthwhile comparison of surgery recovery times between the sets of years.

For these analyses, I have included only surgeries for which I am confident of at least the month that the surgery took place and the month the player returned to action. If anyone feels like helping research, there are many surgeries for which I only know the year, and many older minor league players for whom I do not have game log data indicating when they returned to playing games. Adding detail to these entries would provide more data to analyze.

Tommy John Surgery Recovery Times/Rates, by Era
Surgery Era Return Time (months) Return Rates
Start Year End Year Apr-June July-Sept. Average Median Mode Return Rate Sample Size
2012 2013 13.9* 13.4* 13.8* 13.0 12.0 76%* 97
2010 2011 15.7 15.8 15.7 13.0 12.0 91% 91
2008 2009 15.3 14.1 16.3 13.0 12.0 90% 87
2006 2007 15.8 13.8 14.8 13.0 11.0 88% 84
2004 2005 15.4 18.5 16.9 13.0 13.0 91% 79
2002 2003 14.6 17.3 16.5 13.5 12.0 90% 66
2000 2001 18.8 15.6 17.2 15.0 12.0 90% 46
1974 1999 18.7 17.9 18.3 15.0 13.0 92% 88

*Some players will still return in 2015, which will then increase the average return times and return rate.

A few observations about these numbers: To start, note that the return rate has been remarkably consistent — around the 90 percent level — since the inception of the surgery in 1974. The 2012-13 era with the significantly lower success rate is at least mostly due to the fact that some players who underwent the surgery this recently were not able to return before the end of the 2014 season, but will likely play again in 2015.

There is a perception among the pubic that Tommy John surgery is bad news because a team will lose a player for at least one calendar year. But the chances he returns the following season are high, though not certain. Nine out of 10 is a solid success rate, but it is clear that even with all of the advances made over the years in the surgery technique and rehabilitation process, some players never return to play at the same level of baseball again. As of this writing, I have recorded 87 Tommy John surgeries for professional players in 2014 alone. Given these results, we might expect that eight or nine of those players will never again play at the same level they played before surgery.

It is noteworthy that this figure in the 90 percent range is higher than the 80 to 83 percent success rates found in two studies published in the American Journal of Sports Medicine, as Zimmerman referenced. The difference in results is primarily due to a different player set between this study and those, as my list of players returning from Tommy John surgery encompasses both major league and minor league players.

If I consider only major league players who underwent the surgery between 1974 and 2013, I get a recovery rate of 78 percent. Given that a few players who had the surgery in the past couple of years will still return in 2015, this number will climb slightly. My definition of a returning player also does not have any threshold for games played, as did at least one of the AJSM studies. The return rate for the minor league players I have recorded is more than 93 percent, which drives my overall calculated success rate higher.

Considering recovery times, we can begin by observing that overall times have improved since the earlier years of the surgery. Notice that the average return times for years up to 2005 were in the 17-18 month range. Since then, players have typically returned within 15-16 months of the surgery date. Looking at the column showing recovery times for players who underwent surgery in the second quarter, where a return in the following calendar year could be reasonably expected, there is a fairly dramatic drop from close to 19 months in the early years down to 15-16 months more recently.

While the average numbers tell us one thing, they can be heavily affected by a few players who take several years to return to action. For example, a major league pitcher may take to the mound again following rehabilitation from surgery, toil in the minors for a couple of seasons as he refines his craft, then return to the bigs after a couple of seasons. Given that nobody returns from Tommy John surgery in less than seven months, this makes the tail of the return time distribution much longer than the head.

For this reason, it is prudent to consider the median and the mode for recovery times. We again see some improvement from the early years of surgery, with a very repeatable return time pattern in recent times. Exactly one calendar year has become the most common return time from Tommy John surgery. This number would be smaller for position players, who tend to return quicker than pitchers.

With the enhanced focus on Tommy John surgery in the media, we can ascertain some typical milestone timelines for recovering players. Pitchers tend to start lightly throwing for the first time around four to four-and-a-half months following the date of the surgery. By around the seven-and-a-half to eight-and-a-half month mark, they begin throwing from a flat mound. A month or so after that, pitchers have graduated to throwing from a regulation mound and offspeed and breaking balls are re-introduced. Pitchers first start to face live hitters in the 10 to 11 month range, then tend to start rehab assignments before the one year anniversary of their surgeries — if everything has progressed smoothly.

To summarize, this examination of Tommy John surgery has shown that while the overall success rate has not seemingly improved over time, in recent years players have been able to get back on the field in the same league faster than they did when the surgery was less common.

A second way to analyze Tommy John surgery recovery rate is by age of the player at the time of the surgery. Does it take older players longer to return to action than younger players? What is the attrition rate for players undergoing surgery compared to the typical league attrition rate for players of the same age?

Tommy John Surgery Recovery Times/Rates, by Age
Surgery Age TJS Return Rates
Start Age End Age Avg. Return Time (months) MLB Players All Players Sample Avg MLB Pitcher Return Rate, 1974-2013
12 17 15.3 N/A 100% 20 N/A
18 19 14.4 N/A 97% 61 92%
20 21 15.0 100% 98% 125 93%
22 23 15.4 85% 94% 143 88%
24 25 15.5 84% 91% 124 83%
26 27 15.3 77% 80% 86 80%
28 29 16.9 71% 71% 73 77%
30 31 18.0 82% 81% 43 78%
32 33 15.4 88% 81% 32 76%
34 35 20.1 59% 59% 22 73%
36 50 14.0 77% 79% 14 66%

The sample sizes here for some of the age brackets are very small, so the trend in the return rates is not altogether pleasing to the eye. Nevertheless, we can see that all of the longest average return times occur for players who are 28 or older at the time of the surgery. It would appear that veteran players do tend to require more rehabilitation time before returning to the level they were playing at before the procedure.

As far as attrition goes, there is naturally a downward trend for return rates as players age. Comparing Tommy John survivors to all major league pitchers (injured and non-injured, in the last column) shows that recovering from the surgery tends to occur at around the same rate as typical pitchers manage to stay in the league for a given age range. Some age bands are better, some worse, but with sample sizes this small for Tommy John patients it is hard to make a definitive statement in this regard.


It is interesting to track the surgeon who performed each Tommy John surgery.  I think I am not alone in saying that I figured Dr. James Andrews performed almost every one these days. While Dr. Andrews is the most sought-out physician, in fact a number of currently practicing doctors do Tommy John surgeries.

Identifying the surgeon for surgeries of minor league players is challenging, in particular for procedures occurring in years past, so I will show only the list for surgeries of MLB players. I have determined an attributed surgeon for most of the major league  Tommy John surgeries. If anyone would like to help research, there are still major league surgeries for which no surgeon has been identified, along with surgeries for hundreds of minor league players.

MLB Tommy John Surgery Totals, by Surgeon
Surgeon(s) MLB TJ Surgeries Performed
Dr. James Andrews 110
Dr. Lewis Yocum 66
Dr. Frank Jobe 24
Dr. David Altchek 20
Dr. Timothy Kremchek 19
Dr. Neal ElAttrache 9
Dr. George Paletta 8
Dr. Thomas Mehlhoff 6
Dr. Keith Meister 5
Dr. Wiemi Douoguih 3
Dr. Jan Fronek, Heinz Hoenecke, Daniel Keefe 2
Dr. Michael Lee, Don Sheridan 2
Dr. Thomas Noonan 2
Dr. Bernard Morrey 1
Dr. Dan Buss, John Steubs 1
Dr. Koco Eaton 1
Dr. Ken Akizuki 1
Dr. Stephen Lemos 1
Dr. Larry Pedegana 1
Unknown 45
Total Recorded 327

The first three names on the list should be familiar to most people who have followed the sport for a number of years. Andrews seems to be in the news every day, with fans shuddering at the thought of one of their players having to pay him a visit for fear of bad news to follow. Andrews operates out of two locations – Alabama and Florida. The late Dr. Lewis Yocum was the team physician for the Angels and worked as a colleague of the surgery’s inventor, the late Dr. Frank Jobe, for more than three decades at the famous Los Angeles Kerlan-Jobe Orthopaedic Clinic. Jobe performed the first UCL replacement surgery, of course, on Dodgers southpaw Tommy John in 1974. Jobe was honored at the Hall of Fame weekend in Cooperstown in 2013 for his contributions to the game before his death earlier this year.

Dr. David Altchek is the team physician for the New York Mets. He has placed his stamp on the world of Tommy John surgery through a refinement of the original technique Job developed, which he calls the “Docking Technique.” California-based physician Dr. Neal ElAttrache has teamed with Altchek to further advance the technique, leading to what they have termed the “DANE TJ Technique” (David Altchek, Neal ElAttrache Tommy John).

While the differences between Jobe’s original technique and its refinements are beyond my level of medical expertise, the slight variations may help to explain why players returning for second or third Tommy John surgeries may opt for a different surgeon than did their previous surgery.

Dr. Timothy Kremchek is Cincinnati’s team physician, but has handled Tommy John surgeries for players beyond just those on the Reds roster. Dr. George Paletta works with the Cardinals, Dr. Thomas Mehlhoff with the Astros, Dr. Keith Meister with the Rangers and Dr. Wiemi Douoguih with the Nationals.

Looking at “success rates” by surgeon interests me to some extent, but I feel that many confounding factors are likely even more critical to the eventual success of the patient than the operating physician. The strength of the rehabilitation program, player motivation level and pure luck will also play a big part in whether a player is able to return quickly or even at all.  Also, only a handful of surgeons have performed even a double-digit number of Tommy John surgeries on major league players, so the sample sizes don’t lend themselves to wonderful analysis at this point.

The analysis in this article has been derived from the Tommy John Surgery List I maintain here. I have added two new tabs, “Recovery Time” and “Surgeons” that will update automatically as new entries and more specific information is added into the main list over time.

As always, please let me know if you are aware of any missing entries, or any more specific detail than what is currently recorded for existing entries. The more information that is there, the more research that can be done!

Jon Roegele is a baseball analyst and writer for The Hardball Times. He was nominated for a SABR Analytics Conference Research Award in 2014 and 2015. Follow him on Twitter @MLBPlayerAnalys.
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9 years ago

I think this is a typo. 🙂


Cool article, though I was looking forward to success rate by surgeon.

Paul Swydanmember
9 years ago
Reply to  cass

Oops. That’s my fault. It’s fixed now, thanks for letting me know!

9 years ago

Interesting. Of course, its one thing to pitch in the same league (recover) but the other question is how far away are they from normal, defined as being right before they first started experiencing elbow problems, which may be much earlier than when it progressed to the point they were unable to pitch and had surgery.

The other thing we would want to know is with shorter recovery times, is there an increase in reinjury rate, or an increase in new injuries, and do players come back as close to normal as they did with longer “recovery” times. Also how long does it take them to get closest to normal , which may be some time longer than when they first “recovered”

9 years ago
Reply to  pft

pft…agree…Jamison Taillion and Clay Holmes are two Pirate pitchers who are rehabbing from JT. They both are expected to pitch again (which would make them a ‘success’), but if they both don’t have their ‘stuff’ back, then, in reality, the TJ was a failure.

Not sure how to quantify that for these purposes, but until it can be done, these statistics are fairly useless.

Jon Roegele
9 years ago
Reply to  leefoo

Yes I agree, there are other ways to define “recovered”. I think the problem you get into is that unless you define a particular set of criteria, it gets very subjective. Especially if you’re trying to figure out when a pitcher was last “healthy” prior to the injury. And then if he was a starter and comes back a reliever? Even an elite reliever? It gets hard to compare. I’m certainly not saying that what you guys are suggesting would be useful, it’s more a question of how to define it, and then after that how to mine the data to actually find the dates that meet that chosen criteria. Thanks for the comments.

9 years ago

For completelness’s sake it would be interesting to look at the “return %” of a player who *didn’t* undergo Tommy John, particularly comparing to the age brackets. What percentage of players return to their original league after the off-season? It could be that Tommy John does not add enormously to the standard attrition rate of ballplayers.

Jon Roegele
9 years ago
Reply to  DavidKB

Yes you’re right. I did include this actually, maybe it just wasn’t clear. That’s what the last column, called “Avg MLB Pitcher Return Rate, 1974-2013”, represents in the table that breaks down return rate by age. I used pitchers only since they likely have a different attrition rate than hitters, and almost all Tommy John surgery patients are pitchers.

The Stranger
9 years ago
Reply to  Jon Roegele

What to make of the fact that the TJ return rate seems to be within a few percentage points of the average return rate? I’m trying to wrap my head around the idea that, whether a pitcher had TJ surgery this year or not, he has about the same likelihood of being in the majors two years from now.

Jon Roegele
9 years ago
Reply to  Jon Roegele

Good observation. I guess what it may mean is that the need for Tommy John surgery hits pitchers of all calibers roughly equally. Non-TJ pitchers still drop out of the league, either due to ineffectiveness or occasionally to non-elbow-related injuries. It seems that pitchers who undergo Tommy John surgery come back at around the same rate as that other group – if we assume that those who do return come back to roughly the same level that they were at before they left, then I suppose you would expect around the same percentage to return and be effective enough to warrant a roster spot at the level where they last pitched before injury. Does that make sense at all?

Section 222
9 years ago

Sammy Solis’s surgery was done by Dr. Lewis Yocum (may he rest in peace).

9 years ago

As to the return rate for minor leaguers, there may be a selection bias, in that those who actually have a chance to move up may elect surgery, while those who are just “org guys” may be more inclined not to undergo surgery, and just retire.

Ruben Sendejo
9 years ago

Thanks for all the infor you provided..good stuff! Good to see the younger ages success rate at 100%! You can add my 17 year old to the list of TJ surgeries. Dr Crum from San Marcos performed surgery on Jan far my sons overall confidence towards being able to pitch and play baseball again are great as he has 15 months before his senior season begins. #hardworkwillpayoff

9 years ago

Christian Binford’s surgery was done by Dr. James Andrews.–mlb.html