A History of Shoulder Instability in the Military: Where We Have Been and What We Have Learned

Introduction: Shoulder instability is one of the most common pathologies seen by the orthopedic sports medicine surgeon. With a uniquely young, high-demand patient population in the U.S. Military, the incidence of shoulder instability is remarkably more common than the civilian population. As such, military orthopedic surgeons and sports medicine and shoulder specialists have developed a unique understanding and experience of shoulder instability. The historical advances of shoulder instability in the military have been instrumental in understanding the epidemiology, evaluation, pathology, treatment of first-time shoulder subluxations and dislocations, operative and non-operative treatment options, arthroscopic and open stabilization methods, management of the in-season athlete, treatment of combined and circumferential labral pathology, and associated pathology. Methods: The purpose of this article is to chronicle the experience of military orthopedic surgeons in treating shoulder instability. We discuss how this unique experience has led to a better understanding of the epidemiology and pathology of this condition and how we have adapted our clinical practice to improve patient outcomes. Results: The historical contribution of U.S. Military orthopedics to the understanding of shoulder instability has been monumental. This article reviews the evolution of shoulder instability treatment and the understanding as it has evolved in the U.S. Military. It further elaborates on our understanding of the epidemiology of shoulder instability in the U.S. Military, with attention given to our incidence of 1.69 per 1000 person-years, approximately 20 times higher incidence than the general population. We discuss known risk factors for dislocation that contribute to this incidence, which are specific to military service. We address pathologic changes seen following a first-time instability event, including an analysis of labral injury and the role of these pathologic changes in recurrent instability. We also review our results from arthroscopic evaluation of first-time dislocations and compare the pathologic changes with those following a first-time subluxation. Evaluation of treatment outcomes is discussed, comparing operative and non-operative results as well as open and arthroscopic stabilization in the U.S. Military population and contact/collision athletes. Finally, we address how these results drive our current treatment algorithm. Discussion and Conclusion: The physical demands of military service result in a high rate of shoulder instability relative to the general population. For years military orthopedic surgeons have sought to better understand this pathology and learn how to optimally manage it so as to reduce this heavy burden of disease. This article discusses our experience with treating shoulder instability, provides an overview of the lessons learned, and provides a historical perspective for the evolution of shoulder instability understanding in the U.S. Military.