Corpus: Radial collateral ligament

The radial collateral ligament, abbreviated as RCL, is a short, tough ligament of dense connective tissue that reinforces the joint capsule of the elbow joint. It exhibits significant interindividual differences.

The radial collateral ligament extends from the outer surface of the lateral epicondyle of the humerus to the annular ligament of the radius. Some fibers extend beyond the annular ligament and insert at the interosseous border of the ulna, in the region of the origin of the supinator. The radial collateral ligament is fused with the origin tendon of the supinator muscle.

From a clinical perspective, the radial collateral ligament is often grouped with the annular ligament and other adjacent ligamentous structures as the lateral collateral ligament complex (LCLC) or lateral collateral ligament (LCL). This complex consists of:

• Annular ligament (ligamentum anulare radii)
• Radial collateral ligament (ligamentum collaterale radiale, RCL)
• Lateral ulnar collateral ligament (ligamentum collaterale ulnare laterale, LUCL)
• Accessory lateral collateral ligament (ligamentum collaterale laterale accessorius, ALCL)

The fiber bundles of the LUCL run dorsally around the head of the radius and insert at the supinator crest of the proximal ulna, thus enclosing and stabilizing the head of the radius dorsally.

The radial collateral ligament stabilizes the elbow joint against applied varus stress.