metaphysealepiphyseal

Metaphysealepiphyseal, often written metaphyseal-epiphyseal, is a descriptive anatomical term for the region where the metaphysis meets the epiphysis at the ends of long bones. In the growing skeleton this junction is closely associated with the growth plate, or physis, which enables longitudinal bone growth.

Anatomy: The epiphysis forms the bone end and the metaphysis lies between the growth plate and the diaphysis. In children the physis is a cartilaginous layer separating metaphysis and epiphysis; in adulthood it disappears, leaving an epiphyseal line.

Growth and physiology: Longitudinal growth occurs by endochondral ossification within the physis. The metaphyseal-epiphyseal region contains zones of resting cartilage, proliferating chondrocytes, and hypertrophic cartilage that progressively ossify toward the metaphysis and epiphysis.

Clinical relevance: Injuries or disorders affecting this region can disrupt normal growth and lead to angular deformities or limb-length discrepancies in children. The physis is a key component of many pediatric fracture classifications, including Salter-Harris types I–V, which describe injuries to the growth plate and adjacent metaphysis or epiphysis. Imaging often shows physeal widening, irregular metaphyseal contours, or physeal displacement.

In medical literature the term is used in discussions of growth disorders that involve both metaphyseal and epiphyseal regions, such as metaphyseal-epiphyseal dysplasia, a subset of skeletal dysplasias.

See also: growth plate, physis, epiphysis, metaphysis, long bone, Salter-Harris classification.