Overhead Athletes Have More Subtle Shoulder Instability

Compared to other athletes, throwers and overhead athletes are more likely to have more subtle instability that results in higher rates of subluxations instead of an unmistakable dislocation, a new study finds.

“Athletes of all sports often have shoulder instability, most commonly as anterior shoulder instability. For overhead athletes and those participating in throwing sports, clinical and surgical decision making can be difficult owing to a lack of long-term outcome studies in this population of athletes,” the study authors of “Anterior Shoulder Instability in Throwers and Overhead Athletes: Long-term Outcomes in a Geographic Cohort,” wrote.

The study was published online on November 17, 2021, in The American Journal of Sports Medicine.

The researchers sought to collect data on the presentation characteristics, pathology, treatment strategies and outcomes in anterior shoulder instability in overhead athletes and throwers.

They hypothesized that overhead athletes and throwers would have similar presenting characteristics, management strategies and clinical outcomes, but lower rates of return to play than other athletes.

For the analysis, 57 overhead athletes with anterior shoulder instability were matched 1:2 with non-overhead athletes with anterior shoulder instability. Forty of the overhead athletes were throwers. Overhead sports include volleyball, swimming, racquet sports, baseball, and softball.

Data was collected on patient characteristics, type of sport, imaging findings, treatment strategies and surgical details, return to play and Western Ontario Shoulder Instability Index scores.

Four patients were lost to follow-up at 6 months. The follow-up for the remaining patients was 11.9 ± 7.2 years (mean ± SD).

Overall, the non-overhead athletes were more likely to have dislocations (80%; p = .018). The number of instability events at presentation, however, were similar.

The researchers also found that overhead athletes were more likely to undergo initial operative management. Differences in rates of recurrent instability though were not significant after initial nonoperative management (non-overhead athletes, 37.1% vs. 28.6% for overhead athletes; p = .331 and throwers, 21.2%; p = .094) and surgery (non-overhead athletes, 20.5% vs. overhead athletes, 13.0%; p = .516 and throwers, 9.1%; p = .662).

In addition, rates of revision surgery were similar between all the athletes. Return to play rates were 80.5% in non-overhead athletes compared with 71.4% in overhead athletes (p = .381) and 63.6% in throwers (p = .143). Median Western Ontario Shoulder Instability Index scores were 40 for non-overhead athletes as compared with 28 in overhead athletes (p = .425) and 28 in throwers (p = .615).

“Despite differences in presentation and the unique sport demands of overhead athletes, rates of recurrent instability and revision surgery were similar across groups. Similar outcomes in terms of return to play, level of return to play and Western Ontario Shoulder Instability Index scores were achieved for overhead athletes and non-overhead athletes, but these results must be interpreted with caution given the limited sample size,” the authors wrote.