Enthesis: A Brief Review

Bone is a living tissue capable of changing its structure as the result of the stress to which it is subjected. It consists of cells, fibers and matrix. Calcification of extra cellular matrix makes it hard. The slight degree of elasticity in the bone is due to the presence of the organic fibers. The main function of the bone is protection of some of the vital organs like brain, spinal cord, heart and lungs. It also acts as a lever which helps in locomotion and movement. It is the main storage house of the calcium salts. The cavity of the bone consists of delicate blood forming bone marrow.1 The two forms of bones are compact and cancellous bone. Compact bone exists as a solid mass however the cancellous bone has a branching network of trabeculae. The arrangement of trabeculae is such that it resists the stress and strain to which the bone is exposed. Entheses is an interface where the tendon meets bone. These are the sites of stress concentration at the hard and soft tissue function where mechanical properties differ. They play a pivotal role in the diagnosis of various types of arthritis. However, not much importance has been given by the anatomists and the clinicians towards the study on entheses. This article aims to provide a brief account on entheses to draw the attention towards the known but ignored entity called entheses.