Zimmerman's Tommy John Primer

Ulnar Collateral Ligaments
are fragile when you throw
really hard.

The Reds have fortunately managed to largely avoid entanglement in ulnar collateral ligament repair surgery this year, but it is a major topic of interest in baseball because of the recent spike in the surgery that we are seeing.  Jeff Zimmerman penned the first part of an excellent primer on Tommy John Surgery at Hardball Times.  Of note: 20% of pitchers who have the surgery just don't make it back, velocity does NOT increase in the years following the surgery, and pitchers typically struggle their first year back.

The latter is probably well-known.  But the first point is not well appreciated, and the second is an important myth.  A few month ago, on Effectively Wild, Stan Conte, the VP of Medical Services of the Los Angeles Dodgers, was on for an interview about pitcher injuries.  One of the points he made is that the myth of increased velocity resulting from Tommy John surgery has resulted in some ridiculous scenarios.  Among them are stories of fathers requesting the surgery for their completely healthy sons in hopes of helping them to add velocity.  Can you imagine?

Zimmerman's next piece will investigate probable causes of the injuries.  The biggest culprit in conversations I've read and heard are fastball velocities, which continue to rise.  I'm looking forward to seeing the data on that, and whether those claims hold up.

Update:
I received this tweet last night.  It provides two great links to Jon's work that addresses my last paragraph:

@jinazreds I looked at TJ surgeries and pitch velocities at BtBS in two parts: http://t.co/enLjjKZHqG and http://t.co/LDLTlR3rI4
— Jon Roegele (@MLBPlayerAnalys) July 1, 2014

Update #2:
Here's Zimmerman's second part, with an excellent summary of his findings (all of which I agree with):

1. Pitchers are developing their shoulders better. This leads to a pitcher’s elbow giving out before his shoulder.
2. Pitchers are throwing at a higher velocity, which means more stress on the elbow. More stress means more of a chance for a snap or rip.
3. Younger pitchers are putting undo stress on their arms at too early an age, with too many innings and not enough rest time. The pitchers are damaged goods before they make it to the majors.