Prior underwent right shoulder arthroscopy by Dr. James Andrews in Birmingham, Ala. Andrews cleaned up Prior's right rotator cuff, tightened shoulder capsules and repaired the pitcher's right labrum.
"Obviously he's had some things wrong physically, and he's getting them corrected," manager Lou Piniella said. "So this is a step in the right direction."
this page considered prior to be one of the two probable keys to any hope of success in 2007, along with rich hill. the team has since foundered, but any small hope of a resurgence will be linked with getting the kind of starting pitching that prior might once have provided from someone other than carlos zambrano and hill.
while it certainly is necessary for prior to have undergone this procedure in order to have any hope of a future in baseball, this page would reiterate that labrum repair is the graveyard of starting pitching. the mark prior we see emerge from rehabilitation (if he in fact does) will probably be a faint shadow of the pitcher we saw in 2003.
UPDATE: baseball prospectus' injury specialist will carroll on prior:
So what does this mean? First, it means that Prior had been pitching with significant damage for the past two years. Do NOT take this to mean that he was misdiagnosed. MRIs are imperfect instruments but it does show that this surgery was necessary. The cuff debridement is the most significant injury, but indicates that the tears in the muscles of the cuff were not significant enough to make them structurally unstable. Instead, Andrews would have scraped away scar, loose fragments of tendons, and bursae, as well as any other associated debris from the area.
Second, the capsule repair probably involved a capsular shift. In this the surgeon will make a small incision in the front of the shoulder, then folds an overlap to shrink the capsules circumference. It’s like folding over one of those funny pictures on the back of Mad Magazine.
Finally, the Bankart repair involves stapling, sewing or anchoring the capsular ligaments and glenoid labrum into anchors drilled into the scapula. Despite all this, it can be done completely arthroscopically. It’s as significant as it sounds, but since 2000, there’s been some success with this type of procedure, with several pitchers including Chris Carpenter able to come back to varying levels of success.
All in all, this is a very negative result for Prior, but gives him the knowledge that he was pitching with significant damage.