What structure is primarily involved in Salter-Harris fractures?

Salter-Harris fractures specifically involve the growth plate, also known as the epiphyseal plate, which is a critical area of developing cartilage in children and adolescents. These fractures are classified based on the level at which they affect the growth plate and are essential in pediatric orthopedics because they can significantly influence bone growth and development.

The growth plate is located at the junction of the epiphysis and the diaphysis of long bones and is responsible for the longitudinal growth of bones. An injury to this area can disrupt normal growth and potentially lead to complications such as limb length discrepancies or angular deformities in the affected bone.

While the medullary cavity, articular cartilage, and periosteum are important structures within the bone, they are not specifically targeted in the mechanisms of Salter-Harris fractures. The medullary cavity pertains more to the interior space of bones that contains bone marrow. Articular cartilage covers the ends of bones where they articulate, aiding in joint function, and the periosteum serves as a protective outer layer for bones and a site for muscle attachment but is not primarily affected in Salter-Harris fractures. Therefore, the growth plate's involvement distinctly aligns with the nature of these fractures, making it the primary structure involved