May 18, 2011

Collateral Damage

Stressing Out

by Corey Dawkins, Marc Normandin and Ben Lindbergh

David Wright, NYN (Low Back stress fracture)
Low back stress fractures are a type of overuse injury more common in adolescents than adults, but given the team's recent medical track record, it hardly surprises when even the most unlikely ailment befalls a Met. A stress fracture takes place when the body's ability to build new tissue is overcome by forces that try to break it down. Most classic stress fractures don't involve a clear precipitating event such as a dive for a ball, instead gradually progressing over weeks or months.

Often one particular repeated action is a contributing factor–in the lumbar spine, it is usually hyperextension or bending backwards–but as the condition worsens other actions also become symptomatic. One factor that always plays a role, however, is the muscular and connective tissues' inability to absorb the forces from these actions that break down tissue.

Stress fractures in the lumbar spine often involve an area of the vertebra called the pars interarticularis–pars, for short–but can afflict any area of the vertebra. The pars is located in the area near where vertebrae articulate with each other at the facet joints. Despite the protection afforded by discs between each vertebra, that repeated extension strains this particular area and causes a stress fracture commonly seen in sports that require frequent hyperextension, such as gymnastics, competitive cheerleading, and tennis, as well as baseball and football, which place that demand on linemen and pitchers, respectively. Whether Wright has been indulging in competitive cheerleading on the bench is a question that only his teammates, his coaches, and Mets season-ticket holders seated down the third-base line can answer.

If the stress fracture is not treated properly, it can continue to degenerate and progress into a true fracture, although this is normally not as painful as a similar fracture occurring in healthy tissue. If it continues to progress and involves both the right and left side of the vertebra, it can lead to instability of the spine and even greater dangers.

These pars defect fractures often go undiagnosed until pain has been present for months or years, or until a subsequent injury arises later in life. Some athletes report back pain when younger but go untreated until one particular twist or dive set off more intense pain in their 20s and further imaging reveals the pars defects. Pars defects don't always heal like fractures in many other bones, but in many cases they do become less symptomatic.

Consequently, treatment is often based on a combination of symptoms and diagnostic imaging. If the location of the stress fracture in Wright's back is at the pars, this would be a likely scenario. It is important to note that the pars aren't the only possible location of a stress fracture, as other parts of the vertebra can be involved. There could also be a partial congenital fusion of the last lumbar vertebra to the sacrum.

Regardless of the classification or the exact location of the stress fracture, players with pars issues have not had much success in returning quickly, according to our database (albeit in a small sample size). We have records of only five players diagnosed with low back stress fractures, none of them third basemen. Francisco Cordero lost almost all of 2001 to his stress fracture, while Bobby Crosby missed over 50 games with his as a shortstop in 2006. Two minor leaguers in our database missed over 75 games as a result of stress fractures. Justin Morneau missed “only” 29 days, but his stress fracture ended his season, so he likely would have missed at least another week or two had he suffered it earlier in the season.

The Mets must allow sufficient time for Wright's symptoms to decrease to the point that his play won't be affected, so he will likely be out for a minimum of four weeks, and probably closer to six, if not more.

Daisuke Matsuzaka, BOS (Right elbow sprain/strain)
John Lackey, BOS (Right elbow strain)
Dice-K's trip to the DL isn't surprising given the reports of elbow tightness from a couple of starts ago, as well as his extensive injury history. The fact that his command and velocity have been off recently—even more than usual—sealed the deal for Boston, who decided to have him checked out and put on the shelf.

Matsuzaka has had forearm and shoulder problems in the past, and if the MRI results reveal something major that requires surgery, this may be the beginning of the end for him in Boston. The 2011 season may have been his last chance before Boston could find another starter or promote one from within, and missing a chunk of the season would cut into the persuasiveness of the arguments in favor of retaining him.

Lackey's appearance on the DL for his own elbow issue isn't surprising either, based on his performance. His velocity has declined over the course of his starts recently, which is an oddity for a veteran pitcher, unless there is an underlying injury. Here is his start from May 5 against his former team, the Angels, when he went four innings while using 97 pitches, just 56 of them thrown for strikes:

The velocity on all of his offerings trended downward as the game progressed; not only did he have trouble locating his pitches, but they became less effective in terms of speed, so it should be no surprise that he gave up eight runs that day.

Lackey had elbow issues and arm troubles in 2008 and 2009, so the Red Sox stuck a clause in his contract that allows them to retain him in 2015, after his contract is supposed to have ended, for the league minimum if his elbow causes him to miss significant time. There is no word yet that his elbow injury is that serious or related to his old injury—there are also whispers in the Boston media that this is a DL stint meant to help Lackey clear his head as much as recover from an injury—so that clause may not come into play anytime soon, but remember that it's there to help the Sox recoup some of the value of the contract if Lackey can't take the ball. Then again, given the way things are going, 2015-era Lackey might not be worth rostering at any price.

Rafael Soriano, NYA (Right elbow soreness)
The northeast corridor is turning into a MASH unit, with Soriano joining the disabled list retroactive to May 14. Soriano has a history of elbow injuries—including two surgeries—but a recent MRI showed only inflammation.

His control has been off this year, suggesting something was going on, but the MRI confirmed it. There is no indication that he will be out for an extended period of time, but with any pitcher there is that chance, especially given injuries to the throwing arm.

If the elbow injury persists and keeps Soriano from performing often or performing well, you can be sure he won't opt out of his lucrative contract. Those Yankees fans that want Soriano to opt out so they can get out from underneath the deal may want to start hoping he is healthy sooner than later.

Aroldis Chapman, CIN (Left shoulder inflammation)
Chapman landed on the disabled list with a recurrence of his left shoulder inflammation over the last several days. He walked 12 hitters in a little over one inning spread out over four appearances, so clearly something was not right (or the Cuban Missile just needs a new targeting system). It is somewhat concerning that his inflammation came back, so it is likely something more than simple overuse, possibly involving impingement of some sort.

The Reds are going to be extremely careful with this multi-million dollar arm and are not going to risk any long-term damage for short-term gain. They are overloaded with arms as it is right now, so they can afford to take it easy with the most important of the young ones.

Flesh Wounds: Andrew Cashner aggravated his strained rotator cuff and will rest for two to three weeks before starting the throwing program over again... Derrek Lee will likely be placed on the disabled list today with a strained left oblique... Peter Moylan had successful back surgery and will look to return in late August... Kyle Davies was placed on the disabled list for anterior shoulder soreness after being unable to make it through the first inning on Monday. MRI results are still pending. At least this means prospect that Danny Duffy will get a chance to start... Mitch Stetter went on the disabled list with a left hip injury, although the severity is not known at this time... Adam Lind was finally placed on the disabled list with low back soreness... Cesar Izturis may end up needing surgery on his elbow for numbness in his hand.

Corey Dawkins is an author of Baseball Prospectus. Follow @CoreyDawkinsBP
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Ben Lindbergh is an author of Baseball Prospectus. Follow @benlindbergh
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