Radial collateral ligament of elbow joint explained

Radial collateral ligament
Latin:	ligamentum collaterale radiale
From:	Lateral epicondyle
To:	Annular ligament

The radial collateral ligament (RCL), lateral collateral ligament (LCL), or external lateral ligament^[1] is a ligament in the elbow on the side of the radius.

Structure

The composition of the triangular ligamentous structure on the lateral side of the elbow varies widely between individuals^[2] and can be considered either a single ligament, in which case multiple distal attachments are generally mentioned and the annular ligament is described separately, or as several separate ligaments, in which case parts of those ligaments are often described as indistinguishable from each other.

In the latter case, the ligaments are collectively referred to as the lateral collateral ligament complex (LCLC), consisting of four ligaments:

• the radial collateral ligament [proper] (RCL), from the lateral epicondyle to the annular ligament deep to the common extensor tendon
• the lateral ulnar collateral ligament (LUCL), from the lateral epicondyle^[3] to the supinator crest on the ulna. Near the attachment on the humerus this ligament is normally indistinguishable from the RCL and can be considered the posterior portion of it. described the distal part of the LUCL as "a definite bundle which normally crosses the annular band and gains attachment to the supinator crest, frequently to a special tubercle on that crest" but didn't name it.
• the annular ligament (AL), from the posterior to the anterior margins of radial notch on the ulna, encircles the head of radius and holds it against the radial notch of ulna.^[4]
• the accessory lateral collateral ligament (ALCL), from the inferior margin of the annular ligament to the supinator crest.

Clinical significance

The radial collateral ligament may be involved in lateral epicondylitis.^[5]

References

Bibliography

• Carrino JA, Morrison WB, Zou KH, Steffen RT, Snearly WN, Murray PM . Lateral Ulnar Collateral Ligament of the Elbow: Optimization of Evaluation with Two-dimensional MR Imaging. Radiology . January 2001 . 218 . 1 . 118–25. 11152789 . 10.1148/radiology.218.1.r01ja52118.
• de Haan J, Schep NW, Eygendaal D, Kleinrensink GJ, Tuinebreijer WE, den Hartog D. Stability of the Elbow Joint: Relevant Anatomy and Clinical Implications of In Vitro Biomechanical Studies. The Open Orthopaedics Journal . 2011 . 5 . 168–76. 10.2174/1874325001105010168 . free. 3104563 . 21633722.
• Martin . BF. The annular ligament of the superior radio-ulnar joint. J. Anat. . July 1958 . 92 . Pt3 . 473–82. 1245018 . 13563324.
• Book: Palastanga . Nigel. Soames . Roger. Anatomy and Human Movement: Structure and Function. Elsevier . 2012 . 6th . 9780702040535.

Notes and References

1. As opposed to the "internal lateral ligament", better known as the medial or ulnar collateral ligament
2. , see also Figure 4
3. News: The Elbow Joint. 2012-03-20. TeachMeAnatomy. 2017-07-24. en-US.
4. News: Radio-Ulnar Joints. Earth's Lab. 2017-11-18. en-US.
5. Jacobson. Jon A.. Chiavaras. Mary M.. Lawton. Jason Michael. Downie. Brian. Yablon. Corrie M.. Lawton. Jeffrey. 2014. Radial Collateral Ligament of the Elbow. Journal of Ultrasound in Medicine. en. 33. 6. 1041–1048. 10.7863/ultra.33.6.1041. 2027.42/135312. 1550-9613. free. free.