Poor Mikey.

Mike Lowell has been playing with a partially torn right acetabular labrum since late June.

The hip is a ball-and-socket joint. The head of the femur is the ball and the acetabulum is the name for the socket. Acetabulum comes from the Latin for 'cup' and is, essentially, a shallow indentation in the pelvic bone. It's a feature of the bone designed to give the femur a place to rest and the hip joint a place to work it's magic.

But the socket has to be shallow. If the femur was really jammed into the joint, the range of motion would be lessened. But if it was too shallow, there would be little to hold it in place and it would be easier for the ball to slip out and dislocate the joint-which is extremely painful. That's where the labrum comes into play.

The labrum is a collar-like ring of cartilage that sits on top of the socket. It's function is to make the joint a little bit deeper and help prevent dislocation. When a labrum tears, it becomes harder for it to function usefully. It becomes easier for the joint to slide around (subluxation) or for it to become completely dislocated.

Since they used the word partially to describe his injury and since he still has the use of his right leg, one can probably assume that the labrum is still mostly attached. The pain he's experiencing is probably just subluxation of the joint. But from the look of the pain he's in, it's probably a significant tear (and not just bits of broken off cartilage floating around in the joint.)

The injury shouldn't get significantly worse if he keeps playing. But he'll likely need someone to go in with an arthroscope within a few days of the season ending to patch it up.

*The illustration is from Gray's Anatomy and because Gray's is old, it's labeled as the cotyloid ligament. Also, fair warning: google image searches for acetabular labrum are not for the faint of heart.