Endostet

Endostet is a term used in several European languages to denote the endosteum, the thin, vascularized membrane that lines the inner surfaces of bone, including the medullary cavity and the trabecular surfaces of cancellous bone. The endosteum is composed of a single layer of cells—primarily osteoprogenitor cells and osteoblasts—supported by loose connective tissue and a network of capillaries. It lies in close contact with the mineralized matrix and is intimately involved in bone remodeling.

Functionally, the endosteum provides osteogenic potential, supplying precursors for bone formation and resorption. It participates in growth during development and in fracture repair by contributing new osteoblasts and regulating mineral exchange. The endosteum also acts as a barrier between the bone matrix and marrow cavity, helping maintain the bone’s internal environment. It is distinct from the periosteum, which lines the outer surface of bone.

Clinical relevance: changes in endosteal activity can influence bone strength. Increased endosteal resorption or thinning is often seen with aging and osteoporosis, while localized endosteal activity is important during fracture healing and implant integration. Understanding the endosteal surface is important in orthopedics and histology.

Note: In some languages, the definite form of endosteum is rendered as endostet, endost, or similar variants, referring to the same structure.