A Little Good News About Elbows in Youth Baseball

What’s the Claim?

An extremely well-done prospective study found that preadolescent youth baseball players who underwent a baseline MRI did not experience overgrowth of the lateral structures of the throwing elbow on a second MRI taken 3 years later, when compared to the nondominant arm. These boys were 10 to 13 years old at the time of the study and had played an average of 6 years at the time of the study, so the time interval spans an important period of skeletal development in a population of great interest, making it good news for parents and orthopaedic surgeons alike. Most of these kids were pitchers or catchers, nearly 60% were still playing as of the second MRI (and those children’s elbows did not appear any worse off than those of the boys who’d stopped playing ball), and half of the children played year-round.

How’s It Stack Up?

These findings contrast with similar studies raising morphologic concerns about damage to the shoulders of young throwing athletes, as well as those who have elbow injuries and surgery (in whom capitellar osteochondritis dissecans has been associated with radial head enlargement). High torque loads to the lateral elbow have caused people to wonder whether baseball (and throwing sports more generally) might change the morphology of the developing elbow in ways that could be harmful later on. At least for a mixed population of active but (mostly) non-elite adolescent baseball players, this worry seems unfounded. We have confidence in these findings for several reasons: none of the study participants were lost to follow-up, the measurement approaches were extremely precise, and the study compared the dominant to the nondominant arms in a blinded fashion.

What’s Our Take?

This study offers several practical takeaways. Perhaps the most important one is that if a youth baseball player does present with elbow pain and altered joint morphology on plain x-rays, that elbow deserves a close look (and probably an MRI scan), as osteochondritis dissecans may be hiding out in there. Stated otherwise, baseball alone at this level shouldn’t change an elbow’s shape, so if you see a morphologically abnormal lateral elbow in a growing baseball player, you’ve got to look for a cause. Another is the reminder to read past the top-line finding. A thoughtful commentary accompanying this article reminds us that baseball and other throwing sports like volleyball, tennis, and water polo differ in important ways, and although many of the children in the current study were year-round baseball players, not all were, and so these findings might not generalize perfectly to elite subsets like year-round pitchers. Maintain a higher index of suspicion if one of those boys presents with elbow pain. But the slice of the population studied here is representative of many if not most youth baseball players in terms of intensity and position distribution, making these findings both generalizable and reassuring.

Source

Harkin WE, Pennock AT, Bastrom TP, Edmonds EW. Does Youth Baseball Result in Morphologic Changes of the Lateral Elbow? A Prospective MRI Study. Clin Orthop Relat Res. 2021;479:623-631.

Further Commentary

Fabricant PD. CORR Insights: Does Youth Baseball Result in Morphologic Changes of the Lateral Elbow? A Prospective MRI Study. Clin Orthop Relat Res. 2021;479:632-633.