What does epiphyseal mean?
Epiphyseal is an adjective used in anatomy and medicine to describe anything relating to an epiphysis — the expanded end of a long bone such as the femur or humerus. In children and adolescents, each epiphysis is separated from the bone's main shaft by a layer of cartilage known as the epiphyseal plate, or growth plate, which is where new bone forms and lengthwise growth occurs. When growth is complete, typically in late adolescence, this cartilage hardens and the epiphyseal plate becomes an epiphyseal line. The term appears most often in phrases like 'epiphyseal fracture' or 'delayed epiphyseal closure'. Because injuries to the growth plate can affect how a young bone develops, epiphyseal is an important word in paediatric orthopaedics and radiology, though it rarely surfaces outside specialist medical writing.
adjectiveRelating to an epiphysis, the end portion of a long bone that develops from a separate centre of ossification and later fuses with the bone's shaft.
- Relating to an epiphysis, especially the epiphyseal (growth) plate of cartilage in developing bones.
"The X-ray revealed an epiphyseal fracture at the distal end of the femur."
"Growth hormone deficiency can delay epiphyseal closure, keeping the growth plates open for longer than usual."
"Because the epiphyseal plate is still open in children, fractures near the joint require careful orthopaedic assessment."
Your growth plates — the reason teenagers shoot up in height and stop when they're done — are formally called epiphyseal plates.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of epiphyseal
Epiphyseal derives from 'epiphysis', which comes from Greek 'epi-' meaning 'upon' plus 'phyein' meaning 'to grow', so an epiphysis is literally a part that 'grows upon' the bone. The adjective was formed with the Latin-derived suffix '-eal'. Its relatives include 'epiphyte' (a plant growing upon another plant), and its antithetical counterpart 'diaphyseal', from 'dia-' meaning 'through', referring to the shaft that grows between the two epiphyses.
Related word forms
How epiphyseal is actually used
A technical term used almost exclusively in anatomy, medicine, radiology, and sports medicine. The variant spelling 'epiphysial' also occurs. In clinical contexts it most often appears before 'plate', 'fracture', 'line', or 'closure'.
Easily confused with epiphyseal
Epiphytic describes plants that grow on the surface of other plants, while epiphyseal pertains to the ends of long bones.
Diaphyseal refers to the shaft (middle) of a long bone, whereas epiphyseal refers to its rounded end.