Metaphysis and Epiphysis Definitions
The epiphysis is the expanded end portion of a long bone that typically forms joints. The metaphysis is the region between the epiphysis and the diaphysis that contains the growth plate (physis) in children and adolescents.
Epiphysis Location and Function
The epiphysis is located at each end of a long bone. The articular surface of the bone is part of the epiphysis. In skeletally immature patients, the epiphysis ossifies and contributes to joint formation as development proceeds.
Metaphysis Location and Growth
The metaphysis lies between the epiphysis and the diaphysis. The growth plate (physis) is located within the metaphyseal region in children and adolescents. Endochondral ossification at the physis drives longitudinal bone growth.
Relationship to the Diaphysis
The diaphysis is the shaft of the long bone. The metaphysis connects the diaphysis to the epiphysis through the growth plate region in growing individuals.
Clinical Relevance
Fractures involving the physis and adjacent metaphyseal regions are common in children. Growth-plate injury can affect subsequent bone length and alignment.
Terminology Summary
Epiphysis: end portion of a long bone that forms joints. Metaphysis: region between epiphysis and diaphysis that contains the growth plate in children.