How do you define success? Return to the rotation? Performing as well or better than before TJS?
The data from various studies is conflicting. Here is another one that purports to be "the largest analysis of MLB pitchers who have undergone TJS". The conclusion was that:
"There is a significant proportion of players (18%) who do not resume major league career. For those that return, a high proportion return to the disabled list, both for arm conditions (in general) and specifically for elbow pain (47% and 23%, respectively). Moreover, many performance statistics showed a decline following surgery, most notably in ERA, WHIP, opposing batting average, innings pitched, percentage of fastballs thrown and fastball velocity."
Here is the link: http://www.abstractsonline.com/plan/ViewAbstract.aspx?mID=3358&sKey=493a4472-e6c5-4acf-8c39-7588796fd6a5&cKey=543b49e3-0bf2-4bfe-a036-e3c30c12e41c&mKey=4393d428-d755-4a34-8a63-26b1b7a349a1