epicondyle

The Greek prefix epi means upon or above. Combined with kondylos (knuckle), epicondyle literally means upon the condyle, a secondary projection sitting above the main rounded joint surface. The term is not ancient; it is a New Latin construction assembled in the eighteenth century when anatomists needed vocabulary precise enough to distinguish the condyle itself from the smaller bony flanking projections.

The humerus has two epicondyles, medial and lateral, positioned just above the elbow joint. The medial epicondyle is the bony bump you can feel on the inside of your elbow; striking it against a hard surface compresses the ulnar nerve, producing the electric shock universally known as hitting your funny bone. The lateral epicondyle is smaller but notorious: it is the attachment site for the extensor tendons of the forearm and the location of lateral epicondylitis.

Tennis elbow was named in 1883 by Henry Morris and James Heneage Nicholl, who published in The Lancet on painful lateral epicondyle conditions in racket players. The condition involves microtears in the extensor tendons where they attach to the lateral epicondyle. Golfer's elbow, or medial epicondylitis, affects the flexor tendons on the opposite side and was named by the same anatomical logic.

The patella, mandible, and femur also have epicondyles, but the humeral pair dominates clinical literature. Epicondylar fractures in children are among the most common elbow injuries seen in emergency medicine, particularly the medial epicondyle fracture resulting from a fall on an outstretched hand. The eighteenth-century New Latin coinage now carries a substantial share of pediatric orthopedic case reports.