Apophyseal Physeal Stress Injury (PSI): An Overview

The apophyses develop through endochondral ossification that occurs at the periphery of the enlarging secondary ossification center. Sever’s and Osgood–Schlatter diseases are the most studied sites for traction apophysitis. Regrettably, apophyseal injuries are frequently underdiagnosed and mistaken for soft tissue injuries. These injuries occur from childhood to late adolescence with some diagnosed in the third decade of life. Most sports-related epidemiological research on apophyseal injuries involve the lower extremity, and male athletes, especially in soccer. These overuse injuries are caused by repetitive submaximal mechanical stress beyond the physeal tolerance-threshold, disrupting the periphyseal vascular supply. Avulsions are the most severe presentation. Currently, clinical examination and management of these injuries relies mainly on clinical research and expert opinion. Clinicians should be familiar with the various sites of vulnerability in the immature skeleton which facilitates early diagnosis and intervention, prior to irreversible damage and growth disturbance. Thus, management has evolved into a more active approach, which involves athlete education, activity, and load modification management. We propose a novel framework for understanding the pathophysiologic mechanisms behind these injuries and a structured hypothetical approach to enhance the management of apophyseal PSIs.