epicondylus

Epicondylus, or epicondyle in English, refers to a bony projection located above a condyle on a long bone. These prominences provide attachment points for ligaments and muscles and are common anatomical features in several joints. The term is used broadly in anatomy to describe such projections on different bones, most notably the humerus and the femur.

In the upper limb, the humerus has a medial epicondyle on the inner side of the elbow and a lateral epicondyle on the outer side. The medial epicondyle serves as the origin for the common flexor tendon, while the lateral epicondyle is the origin for the common extensor tendon. The ulnar nerve runs behind the medial epicondyle in the ulnar groove, which can be clinically relevant. In the knee region, the distal femur bears the medial and lateral epicondyles just above the knee joint; these serve as attachment sites for ligaments and surrounding musculature and can be involved in trauma or degenerative processes.

Clinical relevance includes epicondylitis, with medial epicondylitis (golfer’s elbow) and lateral epicondylitis (tennis elbow) representing tendinopathies at the respective humeral epicondyle insertions. Fractures or avulsions of epicondyles can occur with direkte trauma or avulsion injuries, particularly in children or during high-impact events.

Etymology derives from Latin epicondylus, itself from Greek epi (“upon”) and kondylos (“knob”). This terminology emphasizes the location of the projection just above a condyle.