More than 70 percent of intercollegiate athletes returned to playing contact sports within 1 week of experiencing in-season shoulder instability, according to a study presented at the 2014 annual meeting of the American Orthopaedic Society for Sports Medicine. However, nearly two-thirds of the athletes who returned to play continued to have recurrent instability.

“These early results should be valuable to physicians caring for the in-season athlete with shoulder instability because we have not yet reached a consensus treatment approach on these injuries,” noted lead author MAJ Jonathan F. Dickens, MD, of the John A. Feagin, Jr., Sports Medicine Fellowship and Keller Army Hospital in West Point, New York. The study, “Return to Play following In-Season Anterior Shoulder Instability: A Prospective, Multicenter Study,” won the 2014 Aircast Award for Clinical Science.

Obtaining data
The researchers, who sought to determine the likelihood of returning to sport after in-season anterior glenohumeral instability, prospectively enrolled 45 contact intercollegiate athletes throughout the course of 2 years into a multicenter, observational study. Study participants included male and female basketball, soccer, lacrosse, or football athletes. Researchers focused on the patients’ ability to return to sport as well as the amount of time lost from sport following an acute anterior shoulder instability event. The following baseline data were collected:

• sport played
• previous instability events
• direction of instability
• type of instability—subluxation or dislocation

The investigators obtained several patient-reported outcomes scores at the time of injury including the Western Ontario Shoulder Instability Index (WOSI) and Simple Shoulder Test (SST). Following the initial shoulder instability event, all observed patients participated in a standardized, accelerated rehabilitation program without shoulder immobilization. During the course of the competitive season, the researchers identified whether study participants were able to return to play and whether they experienced recurrent shoulder instability.

Assessing results
After a median of 5 days lost from competition, 33 of 45 athletes (73 percent) returned to sport for either all or part of the season. Of those who returned to sport, 21 athletes (63 percent) experienced recurrent instability.

Compared to athletes who sustained a complete dislocation, athletes who sustained a subluxation were 5.3 times more likely to return to sport after first experiencing in-season shoulder instability.

The results of logistic regression analysis suggest that scores obtained from the WOSI and SST, administered after the initial instability event, are helpful in predicting an athlete’s ability to return to play. Specifically, the investigators found that, for every 1 point higher the WOSI scale score at the time of injury, the athlete had a 5 percent higher likelihood of returning to play during the same season.

Of all the outcomes measures used, “the SST demonstrated the strongest correlation with time lost from sport,” noted the authors. “For every 10 points higher the SST scale score was at the time of injury, an athlete returned to sport 1.2 days sooner.”

Overall, the study suggests that subluxation injuries and dislocation injuries may both lead to recurrent instability.

“More research is needed to determine the effect of multiple recurrent instability events on long-term outcomes,” said Dr. Dickens.

Dr. Dickens’ co-authors included Brett D. Owens, MD; Kenneth L. Cameron, PhD, MPH, ATC; Kelly G. Kilcoyne, MD; C. Dain Allred, MD; Steven J. Svoboda, MD; Robert T. Sullivan, MD; John M. Tokish, MD; Karen Y. Peck, MEd, ATC; and John-Paul H. Rue, MD.

Disclosure information: Dr. Dickens—Society of Military Orthopaedic Surgeons (SOMOS); Dr. Owens—Mitek, Musculoskeletal Transplant Foundation, SLACK Incorporated, American Journal of Sports Medicine, Orthopedics, Orthopedics Today, AOSSM; Dr. Svoboda—AAOS, AOSSM, American Board of Orthopaedic Surgery; Dr. Sullivan—SOMOS; Dr. Tokish—Journal of Shoulder and Elbow Surgery, Orthopedics Today; Dr. Rue—Knee, SOMOS; Drs. Cameron, Kilcoyne, and Allred, and Ms. Peck—no conflicts.

Bottom Line

• This prospective, multicenter trial included 45 intercollegiate athletes (both males and females) who played basketball, soccer, lacrosse, or football.
• The researchers found that more than 70 percent of intercollegiate athletes returned to contact sports within 1 week of an in-season shoulder instability event.
• Nearly two-thirds, or 63 percent, of those athletes who returned to sport experienced recurrent instability.
• Compared to athletes who sustained a complete dislocation, athletes who sustained a subluxation were 5.3 times more likely to return to sport after initial in-season shoulder instability.
• The investigators concluded that both subluxation injuries and dislocation injuries may result in recurrent instability and called for additional research to identify long-term patient outcomes associated with recurrent shoulder
  instability.