If one is inclined to believe in things like superstitions and curses, it was indeed Friday the 13th when Baltimore Orioles pitcher Jason Hammel took the mound to face the Detroit Tigers (and I was in Baltimore for a meeting of the American Orthopaedic Society of Sports Medicine). A right knee that had been giving Hammel intermittent trouble for more than two months decided to call it quits, and he exited the game in the fourth inning. Hammel is expected to undergo surgery Monday and is initially projected to be absent for three to four weeks, although it could extend beyond that time frame, depending on his individual recovery.
The Orioles' official website reported an MRI taken Saturday on Hammel's knee indicated that cartilage "had shifted to an area that caused more discomfort on the joint." The description would suggest a loose fragment or a meniscal tear. According to Steve Melewski of masnsports.com, Hammel said, "They'll go in and pull out the cartilage that is floating around and see if there is anything else in there that we haven't caught." The word "floating" suggests the presence of a loose body or cartilage fragment that, in its own right, is fairly benign. Like in the case of Miami Marlins outfielder Giancarlo Stanton, who was forced to have in-season surgery because of a similar issue, the problem arises when the fragment makes it difficult to maintain normal joint motion and creates increased discomfort. Both players were hoping to delay surgery until the offseason, but neither was able to do so.
The good news for Hammel is that the surgery and subsequent rehab are expected to be relatively straightforward. The primary issue initially is resolving any inflammation and restoring full knee motion followed by strengthening and his return to a throwing program. As Hammel acknowledged, continuing to try to play with a painful knee could ultimately threaten his arm and have far more significant consequences.