With one exception, the recent injury news in baseball has been more of the day-to-day or week-to-week variety—the kind of ailments that a club can handle with a few weeks left in spring training. In light of his history of elbow problems, Andrew Bailey put everyone through a scare when he was forced to leave a game yesterday, but he should be all right. However, we can't be quite as optimistic about a certain Orioles pitcher's chances of pitching soon.

Justin Duchscherer, BAL (Right hip)

As we pointed out in Baltimore’s Team Injury Projection, Justin Duchscherer had a higher injury risk than the namesake of CHIPPER himself. Duchscherer has had a rough last several years, missing time for two hip surgeries in addition to elbow surgery. The Orioles were hoping to get the healthy and productive Duke of old, but it doesn’t look like that will happen, since he is still having difficulty with his left hip. He underwent an MR arthrogram, the results of which showed no new damage. (Note the careful wording.) MR arthrograms are performed by injecting the joint with a substance that reveals greater detail of the area and its surfaces upon analysis.

Duchscherer himself is quoted as saying that his hip feels the same as it did prior to the surgery. If the MR arthrogram shows no new damage, and it did not show anything that the doctors didn’t expect to see, what does that tell us? First, something in the hip is clearly giving him issues—the hip doesn’t just become sore on its own. Some knowledge of the hip's structure is vital to understanding its role and function, and the possible reasons for pain. The hip is a ball-and-socket joint that is normally very stable. It takes a great amount of force to injure the joint—fractures and dislocations of the hip are considered medical emergencies. What we are seeing more and more of, however, are labral tears from chronic degeneration in a younger population, as well as fraying of the labrum, which is similar to the labrum in the shoulder. These labral tears are often the result of something called femoral acetabular impingement, or FAI, for short, exactly what Duchscherer suffered last year prior to surgery on his left hip.

There are two main types of impingement in the hip, and both can be limiting to athletes who have to bend from the middle and rotate. The first common type of impingement is cam impingement, in which a bump—like a bigger, smoother, bone spur—grows on the femur. This causes the labrum to be banged, pinched, and torn as a result of the compression between the cam lesion and the hip socket. This type of impingement is usually most painful with motions that bend the hip, bring it across the body, and twist the ankle outward.

The second common type of impingement, pincer impingement, is the result of the hip socket essentially being too big for the head of the femur. This over-coverage can be limited to the front or surround the entire hip joint. The resultant forces are carried through the labrum and into the underlying hip-socket bone itself. These also produce labral tears, but they are usually more degenerative in nature, causing the body to deepen the cup as a protective mechanism. The pincer impingement can be thought of as the difference between a golf ball sitting on an oversized tee and progressing into more of an egg crate (with some exaggeration for description purposes). Both can result in limited motion, labral tears, and injuries to the cartilage of the top of the femur, but the mechanisms behind them are different.

These days, surgical intervention for these impingements involves dealing with the labral tears by trimming them down (because the tears are not of sufficient quality to be stitched together). If the torn piece is large enough and of a sufficiently high quality, then a primary repair such as suturing may be performed. At the same time, surgeons can also address the bony abnormalities causing the impingement by shaving the bone down to provide ample clearance. If the articular cartilage is involved, a microfracture procedure may also be performed. Usually the athlete is out for about 4-6 months, depending on activity level, sport, general fitness beforehand, surgical procedure, etc.

To return to Duchscherer: what did the doctors see, and what did they expect? We don’t have access to his medical files, but there was likely some damage to the articular surface that could not be fully addressed either at the time of the surgery or during the rehabilitation. If it was addressed at the time of surgery, it may have been smoothed down, or smoothed down and then microfractured. Microfracture is not always successful, and the articular surface doesn’t always become fully smooth again.

The reports that Duchscherer’s hip shows no new damage and that there are no structural issues leads us to believe that this is a cartilage problem. If it is the cartilage, then he will likely miss significantly more time, because the cartilage does not heal on its own. If he does return, there is a good chance that this condition could linger throughout the year. He will try to resume pitching once he is pain-free, but as we said before, there is no guarantee that he will be able to do so successfully.

Andrew Bailey, OAK (Strained right forearm)

After visiting Dr. Andrews, Andrew Bailey was diagnosed with a strained right forearm and can resume throwing when he is pain-free. Even though he had surgery at the end of last year to remove bone chips from the elbow, sometimes a strain is simply a strain. He already underwent Tommy John surgery while he was in college in 2005, and he reported that this latest injury did not feel the way his earlier one did. He will likely be down for at least another week (though it could certainly be longer). The last thing Bailey and the Athletics want is any type of cascade injury, so they will be careful with him and his recovery.

Placido Polanco, PHI (Left elbow hyperextension)

Polanco and the Phillies got a scare on Tuesday after he hyperextended his surgically-repaired left elbow on a swing and felt pain. Remember that his surgery last season wasn’t needed only to remove loose bodies, but also to repair the extensor tendon that caused chronic inflammation throughout 2010. Polanco and the Phillies are downplaying the injury, but this will be important to monitor. If he cannot control the bat either during or after his swing, he will be more prone to a return of this tendinitis, and perhaps further injury to the joint. Polanco and his team are taking it one day at a time, hoping that this won’t turn into another Chase Utley situation—Wilson Valdez can fill in at only one position at a time, you know.

Brad Lidge, PHI (Right biceps tendinitis)

Lidge had to be scratched from Monday’s planned appearance due to tendinitis in his right biceps. We previously discussed the role of the biceps at the shoulder, but it also has an important function at the elbow. The biceps is the major decelerator of the elbow as it moves into extension. Where curveballs are concerned, it has the additional responsibility of supinating, or turning the palm up, providing the rotation required to produce the necessary movement. Lidge has a long history of elbow troubles, and this could be a warning sign of further problems to come. The latest update from General Manager Ruben Amaro Jr. is that Lidge played catch on Tuesday and could resume throwing on Thursday if everything goes well. Spring training has done everything it can to suck the optimism out of the Phillies’ offseason, hasn’t it?

Ryan Zimmerman, WAS (Groin strain)

Lately it's seemed that any time we've labeled a player "The Big Risk" in the TIP series, something bad befalls him, and Zimmerman has become the latest victim: the franchise third baseman is expected to miss about a week with a groin strain. “Only a groin strain, what’s so bad about that?”, you ask. Two things: first, the hot corner requires sudden jumps that could stress either groin on any play, and second, he has to make the throw across the diamond. Sure, Zimmerman could use more of his arm and sling the ball over to first, but he still has to take some sort of step. If he changes his throwing mechanics, he could end up straining a muscle in his shoulder, or worse—it’s less likely for him than it would be for a pitcher, but it is possible. Either way, groin strains tend to linger, and Zimmerman already suffered from hamstring issues in 2010. A one-week recovery seems reasonable, but we’ll see how quickly he can get over this one.

Flesh Wounds: Danny Espinosa fouled a ball off of his foot on Tuesday and was diagnosed with a contusion. As we know from the case of Francisco Cervelli, sometimes there is more to it than that. Espinosa will have further testing later today… Dontrelle Willis sprained his right ankle after tripping over a bat on Saturday. He threw on Monday and should be considered day-to-day… Mat Gamel finally made his spring debut on Tuesday after losing time to his oblique strain… Casey Blake was diagnosed with inflammation in his lower spine, but there is no specific timeline for his return. On the plus side, no further tests are planned… Ian Stewart is scheduled to start today, as he returns from a bone bruise and sprained MCL in his right knee.

Check back tomorrow for the next installment of the Team Injury Projections, as we move on to the Central divisions.