Recurrent shoulder instability among athletes: changes in quality of life, sports activity, and muscle function following open repair

Background: Recurrent anterior shoulder instability is a disabling condition in young athletes with possibly underestimated impact on quality of life and sports activity. Commonly used clinical scoring systems do not reflect the impairment of quality of life and sports activity. It was our aim to assess the return to preinjury levels of quality of life and sports activity as well as the changes in muscle function among competitive and recreational athletes. Hypothesis: Patients suffering from post-traumatic recurrent shoulder instability have to adopt their participation in sports and therefore discover a reduction in quality of life. Open stabilization procedures are able to improve shoulder function and to reduce recurrence rates. However, return to preinjury shoulder function is not guaranteed. Study design: Retrospective longitudinal cohort study on 19 consecutive athletes with recurrent, post-traumatic shoulder instability. All patients were treated with an open, capsulo-labral repair. The minimum follow-up was 24 months. Methods: Life quality (SF12) and sports activity data (Athletic Shoulder Outcome Scoring System) were retrospectively collected for the time before injury (time 1) and for the time with recurrent instability (time 2). Two years after surgical stabilization (time 3), we followed our patients with different clinical outcome scores, rotator surface EMG measurement, isokinetic muscle strength testing, and a radiological evaluation. This design of a three-step follow-up allowed for calculating the impact on quality of life and sports activity following the injury. Results: Two years after surgery, the clinical scoring systems revealed good-to-excellent results in all patients. Quality of life physical component summary remained diminished by 9.2% despite the surgical procedure and was therefore significantly lower as compared to preinjury levels (p < 0.05). Sports activity was also significantly lower at the time of follow-up (p < 0.05). In this specific procedure, external rotation was not impaired postoperatively. EMG testing showed an overall reduction of muscle activity, however not significant. Isokinetic muscle strength was significantly diminished for external rotation and shoulder abduction. Conclusions: Open reconstruction procedures for recurrent shoulder instability can restore shoulder function and stability to near-normal values. Despite good-to-excellent clinical results, there is a significant impairment of quality of life and sports activity 2 years after surgery. Muscle activity and muscle strength are diminished. Recurrent shoulder instability remains a disabling condition to the young athlete. Future strategies have to emphasize restoration of quality of life, sports activity, and muscle function.