Posterior Instability/Posterior Labral Injury in an Overhead Athlete

Abstract

Posterior shoulder instability is less common than anterior instability, comprising 2% to 12% of shoulder instability patients (Wolf and Eakin, Arthroscopy 14:153–163, 1998). While acute posterior dislocation can lead to posterior instability, it is more commonly observed in competitive athletes participating in upper extremity-dominant sports, such as baseball, volleyball, weight lifting, and football (Bradley et al., Clin Sports Med 27:649–670, 2008; Lenart et al., Arthrosc J Arthrosc Relat Surg 28:1337–1343, 2012). It is also observed in patients participating in military training (Antosh et al., Sports Health 8:520–526, 2016). Posterior instability can be a sequela of injury to various structures including the glenoid, labrum, capsule, or glenohumeral ligaments (Antosh et al., Sports Health 8:520–526, 2016). As a result, posterior instability can present multiple ways, often making diagnosis and treatment difficult. Patients may present with frank dislocation (rare), recurrent posterior subluxation, or only pain. Advancements in high-resolution diagnostic imaging and arthroscopic surgical technique have led to high rates of stabilization, pain reduction, and return to competitive sport participation (Arner et al., Arthrosc J Arthrosc Relat Surg 31:1466–1471, 2015; Bahk et al., Arthrosc J Arthrosc Relat Surg 26:1172–1180, 2010). The following clinical vignette explores the diagnosis, management, and follow-up of posterior instability in a high-level athlete.