It looks as though rookie phenom Stephen Strasburg’s magnificent first season pitching in the major leagues will end abruptly. Multiple media sources are reporting that the rookie pitcher has been diagnosed with an ulnar collateral ligament injury of this elbow. This devastating injury will likely require surgery and could cost him most, if not all, of the 2011 season, not to mention the remainder of this season.

Strasburg first demonstrated difficulties with his elbow after throwing a pitch in a game Saturday night. initially reported that he suffered a flexor-pronator strain of his elbow. This is a mild injury of the muscles that come off the inside of the elbow that help to flex the wrist and pronate the form. Although a painful injury, a flexor-pronator strain usually heals with rest, physical therapy, and progression through a throwing program prior to returning to pitching. That type of injury usually improves over 2 to 8 weeks.

Reportedly, the Washington Nationals’ medical staff performed an MRI shortly after the injury. According to, the MRI was somewhat inconclusive, and a second MRI with dye was performed. I don’t know exactly the course of events or the findings on examination of Strasburg’s elbow or his MRIs. I suspect that his first MRI showed some signal abnormality within the ligament, but it likely did not show a definitive tear. Therefore, I think that the Nationals’ team physician ordered what’s known as an MR arthrogram for a more definitive diagnosis.

An MR arthrogram is similar to a regular MRI with an additional procedure involved. In this test, a radiologist injects contrast into the elbow and then performs the MRI as normal. The contrast within the elbow can help make the diagnosis of an ulnar collateral ligament injury with much more certainty, and it can detect partial tears. The contrast will travel all around the elbow, and in this case, the fluid will travel through the ligament and into the soft tissues outside of the elbow joint. The fact that the dye can leak out from under the ligament helps prove that the ligament is torn. Also the fluid can leak into the undersurface of the ligament, demonstrating a partial tear.

You might question why the doctors did not get an MR arthrogram in the first place. While it would be helpful to have the most definitive test done in every situation, an MR arthrogram is not always the first-line test. In this case, if the doctors suspected a flexor-pronator strain, an MRI without contrast injected would be sufficient at showing an injury to this muscle–tendon group. Also, as anyone who has undergone an MR arthrogram will tell you, it is not the most pleasant procedure. While getting fluid injected in your elbow is somewhat painful, the real discomfort from the procedure is felt for four or five days after the test. As with any joint in which an MR arthrogram can be performed, whether it is the elbow, shoulder, knee, or ankle, a joint filled with excessive fluid will be sore for several days while the body resorbs the fluid. This swelling within the joint can be very uncomfortable, so most physicians will not ask patients to undergo this procedure unless the additional arthrogram is felt to add value to the diagnostic test.

Nationals’ officials have not released much information about this test other than sources have reported that he has an injury to the ulnar collateral ligament. This is, in fact, the Tommy John injury. What isn’t known is whether or not this is a sprain of the ligament, or a partial or complete tear of it. If it is a partial or complete tear of the ligament, unfortunately he will likely require reconstructive surgery. Nonsurgical treatment for a complete tear or even a partial tear is usually unsuccessful.

Surgery involves taking a tendon, usually from the wrist on the same side or opposite side as his injured elbow, and using it to make a new ligament. This is anchored into the bone of his humerus and his ulna. Rehabilitation is a very long process. Initially the elbow is kept in some degree of immobilization to help a ligament graft heal. Motion is then slowly restarted and exercise program to regain strength of the upper extremity is started. It is several months before any type of throwing is started, and return to pitching at the major-league level would likely take 10 to 12 months. Therefore, if surgery is decided to be the best option for Strasburg, you can expect that the surgery will be performed fairly soon in order for the rehabilitation process to be completed as soon as possible. If you do the math, it’s hard to imagine that he will pitch in much of the 2011 season.

Fortunately the results of Tommy John surgery have been extremely encouraging. Multiple authors have reported that pitchers return to the same or higher level of competition anywhere from 75 to 95% of the time. There are numerous examples throughout Major League Baseball of pitchers who have undergone Tommy John surgery and have gotten back to being extremely effective pitchers. While this is a potential devastating injury for Strasburg and the Nationals in the short term, it might not derail his stellar career in the long run.

Addendum (August 31, 2010): The Associated Press is reporting that Strasburg is scheduled to have surgery September 3 by Dr. Lewis Yocum.

Please see my posts about ulnar collateral ligament injuries of the elbow and flexor-pronator strains.