Background: Changes in the dominant shoulder and elbow of professional pitchers have been noted on radiographs, magnetic resonance imaging scans, and ultrasound studies. The relationship of these findings to future injury and to time lost from play has not been identified.
Hypothesis: Degenerative changes of the shoulder and elbow are common findings on the radiographs of asymptomatic Major League Baseball pitchers. The changes are cumulative with increased pitching. These findings are not predictive of time on the disabled list.
Study design: Cohort study (prognosis); Level of evidence, 4.
Methods: Fifty-seven asymptomatic Major League Baseball pitchers participating in the St Louis Cardinals spring training camp underwent routine preseason radiographic screening of their dominant shoulder and elbow between 1986 and 1998. Radiographs were reviewed for osteophytes, cystic changes, joint-space narrowing, and loose bodies. All findings were recorded as present or absent. Public baseball records were reviewed for arm dominance, age, years of professional pitching, professional innings pitched, shoulder or elbow injury or surgery, and time on the disabled list. These factors were statistically evaluated for their possible association with findings seen on preseason radiographs.
Results: Shoulder radiographs were available for 57 pitchers, and elbow radiographs were available for 56 pitchers. Both groups had an average age of 29 years. The average number of radiographic findings was 3 for the shoulder and 7 for the elbow. Comparing pitchers on the disabled list for a shoulder or elbow injury with those not on the disabled list demonstrated no significant difference in the age, number of seasons pitched, or number of innings pitched between the 2 groups. When individual radiographic findings were compared, no single finding was predictive of disabled list status (P >.05 in all cases). The sum of radiographic findings for the shoulder was significantly correlated with the number of innings pitched in professional baseball (Pearson correlation coefficient, 0.46; P =.0004). The elbow data showed a similar correlation (Pearson correlation coefficient, 0.38; P =.003). When select individual radiographic findings were evaluated for an association with the number of innings pitched, the presence of acromioclavicular joint findings in the shoulder and radial head osteophytes and radioulnar joint findings in the elbow increased with an increase in innings pitched (P <.05).
Conclusion: Professional pitchers develop degenerative changes over time in both the shoulder and elbow of their dominant (pitching) arm due to chronic repetitive stresses placed across the joints. These findings do not predict time spent on the Major League Baseball disabled list.