diaphysäre

Diaphysär is an anatomical term used to describe things related to the diaphysis, the central shaft of a long bone that lies between the proximal and distal epiphyses. In English, the corresponding adjective is diaphyseal. The diaphysis is the portion of the bone mainly composed of compact (cortical) bone, forming a dense outer wall around a relatively narrow medullary cavity.

The outer surface of the diaphysis is covered by the periosteum, while the inner surface and the medullary cavity are lined by the endosteum. The medullary cavity typically contains yellow bone marrow in adults and is supplied by nutrient vessels that enter the bone through a nutrient foramen. The diaphysis is adapted to resist bending and torsional stresses due to its thick cortical wall.

Clinically, the term is used to describe injuries, diseases, or imaging findings that involve the shaft of a long bone. For example, a diaphyseal fracture refers to a fracture of the bone’s shaft, as opposed to metaphyseal or epiphyseal fractures near the ends. In imaging and histology, diaphyseal bone is characterized by its predominance of lamellar compact bone, in contrast to the more trabecular-rich metaphysis and epiphysis near the ends of the bone.

The term appears in German as diaphysär and in English as diaphyseal, both serving to specify location and characteristics related to the long-bone shaft.