Sports-related injuries of the shoulder: instability.

With current technology a properly conceived imaging strategy can demonstrate instability lesions in the athlete. Plain radiographs can diagnose acute dislocations and assess successful reductions. In addition, plain radiographs can demonstrate Hill-Sachs and, more importantly for instability, osseous Bankart lesions. In the acute setting, conventional MRI nicely demonstrates labral Bankart, ligamentous. and tendonous injuries that result from dislocations and can lead to instability. In the setting of chronic instability, MR arthrography best evaluates these lesions. In the postoperative shoulder, muitislice CT arthrography may be the modality of choice, but further investigation is needed. If large series validate multislice CT arthrography for the evaluation of postoperative instability lesions, this technique may become widely used in athletes and in other populations where recurrent instability is a problem. Other imaging strategies may also find an increasing central role in evaluating shoulder instability lesions. Indirect MR arthrography, for example, may have a role in assessing these lesions in athletes . Another intriguing technology for this application is the development of high field (0.5 Tesla or greater) open magnets. In such a setting, physiological relationships in the shoulder with motion and stress may be evaluated. Such imaging may farther illuminate our understanding of the stable and unstable shoulder. Unfortunately, with all imaging modalities, whether widely used or experimental, outcomes data is Lacking. How do the various imaging modalities and strategies affect patient outcome? The answer is unknown and needs to be answered before a definitive patient work-up for shoulder instability can be established.