The radial collateral ligament or radioscaphoid ligament is one of the intracapsular, extrinsic radiocarpal ligaments and a radial stabilizer of the wrist 1-3.
The radial collateral ligament connects the radial styloid process with the scaphoid running in a fan-shaped, fairly longitudinal orientation forming the most radial part of the radiocarpal joint capsule. It is located deep to abductor pollicis longus and extensor pollicis brevis tendons 1-6.
The proximal insertion or origin of the radial collateral ligament is the radial styloid process, radially and slightly dorsally located in relation to the origin of radioscaphocapitate ligament 1-3.
The radial collateral ligament inserts distally at the radial surface of the scaphoid bone 1-5.
The radial collateral ligament can be visualized on ultrasound with the transducer placed at the radial side of the pronated wrist with mild ulnar deviation in the longitudinal plane. The long axis of the ligament is displayed as an echogenic, fibrillar structure attaching the distal radius to the scaphoid 2-4.
The radial collateral ligament is seen on MRI as a linear low signal intensity structure extending from radial styloid to the radial surface of the scaphoid bone. It can be best appreciated on coronal 3D images or MR arthrogram 4.
The ligament is involved in the following pathologic conditions 6:
- nondissociative carpal instability (CIND)
- ulnar translocation (type 1): rheumatoid arthritis, Madelung deformity
- 1. Mayfield JK, Johnson RP, Kilcoyne RF. The ligaments of the human wrist and their functional significance. (1976) The Anatomical record. 186 (3): 417-28. doi:10.1002/ar.1091860307 - Pubmed
- 2. Türker T, Sheppard JE, Klauser AS, Johnston SS, Amerongen H, Taljanovic MS. The radial and ulnar collateral ligaments of the wrist are true ligaments. (2019) Diagnostic and interventional radiology (Ankara, Turkey). 25 (6): 473-479. doi:10.5152/dir.2019.19036 - Pubmed
- 3. Gitto S, Draghi F. Normal Sonographic Anatomy of the Wrist With Emphasis on Assessment of Tendons, Nerves, and Ligaments. (2016) Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine. 35 (5): 1081-94. doi:10.7863/ultra.15.06105 - Pubmed
- 4. Taljanovic MS, Goldberg MR, Sheppard JE, Rogers LF. US of the intrinsic and extrinsic wrist ligaments and triangular fibrocartilage complex--normal anatomy and imaging technique. (2011) Radiographics : a review publication of the Radiological Society of North America, Inc. 31 (1): e44. doi:10.1148/rg.e44 - Pubmed
- 5. High-resolution MR imaging of the ulnar and radial collateral ligaments of the wrist. ECR 2015 / C-0123 EPOS ECR 2015
- 6. Khan M, Lim WY, Resnick D. Carpal Instability. MRI Web Clinic - June 2012 Radsource - MRI Web Clinic - June 2012