Posterior Shoulder Instability in the Throwing Athlete

Abstract

Posterior capsulolabral injuries are common problems faced by athletes, especially throwing athletes. Posterior shoulder instability can occur as a result of multiple mechanisms, including acute traumatic events, or a more insidious process of repetitive throwing. An understanding of the pathomechanics and pathoanatomy of posterior instability in the throwing shoulder is essential in order to effectively manage throwing athletes. Athletes will more commonly complain of shoulder pain and difficulty with throwing rather than of shoulder instability. A thorough physical examination to identify potential underlying causes as well as specific maneuvers to elicit posterior instability are important in the evaluation and workup of the throwing athlete. Appropriate imaging, including with plain radiographs and advanced imaging assist in decision-making. Treatment options include both nonoperative intervention with a heavy reliance on physical therapy and surgical intervention consisting of arthroscopic posterior labral repair. Recent advancements in our understanding of shoulder biomechanics and posterior shoulder instability, improvements in diagnostic abilities via examination, imaging, and intraoperative evaluation, as well as advancements in arthroscopic techniques have allowed surgeons to better identify and appropriately manage posterior capsulolabral pathology in athletes.