Supinator Crest

crista musculi supinatoris

The supinator crest is a sharp ridge on the outer side of the upper ulna, running downward from the back edge of the radial notch. Part of the supinator muscle arises from it and from the hollow in front of it (supinator fossa). A small tubercle on the crest is the attachment of the lateral ulnar collateral ligament, an important stabiliser of the elbow.

Anatomical Data

Structure & Landmarks

Articulations	No joint; muscle and ligament attachment ridge
Landmarks	Runs distally from the posterior margin of the radial notch Origin of part of the supinator Tubercle of the supinator crest (lateral ulnar collateral ligament attachment) Supinator fossa in front of it
Ossification	Part of the proximal ulna, formed from the primary shaft centre; the crest becomes more prominent with muscle and ligament pull.

Clinical Relevance

Clinical Notes

The tubercle on the supinator crest is the distal attachment of the lateral ulnar collateral ligament, the main restraint to posterolateral rotatory instability of the elbow. In surgical reconstruction of this ligament, a bone tunnel or anchor is placed at the tubercle. Avulsion or tearing of the ligament from the crest follows elbow dislocations and can also result from repeated steroid injections or surgery for tennis elbow.

Pathology

Common Injuries & Conditions

Posterolateral Rotatory Instability of the Elbow

Instability caused by injury of the lateral ulnar collateral ligament at the supinator crest, causing clunking, catching and pain when pushing up from a chair.

Elbow Dislocation

Displacement of the elbow joint, which often tears the lateral ligament complex including its attachment at the supinator crest.

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