Lydia Kuo-Bonde MD, Presenter: Nothing to Disclose

Sulabha Masih MD, Abstract Co-Author: Nothing to Disclose

George Robert Matcuk MD, Abstract Co-Author: Nothing to Disclose

Kira Chow MD, Abstract Co-Author: Nothing to Disclose

With neutral variance, the radius typically bears 80% of a given load, while the ulna only 20%. The significance of this is seen when there is ulnar variance. Mean ulnar variance is 0.9 mm. A 2.5 mm positive ulnar variance more than doubles the force placed on the ulno-carpal joint and triangular fibrocartilage from 18% to 42% while a 2.5 mm negative ulnar variance increases the force placed on the lunate. This review will present key imaging findings and pathology associated with both positive and negative ulnar variance. Recognizing ulnar variance and its sequelae is essential for appropriate management.

1. Definition and examples of ulnar variance. 2. Radiographic presentation of pathology related to positive ulnar variance: Ulnar impaction syndrome, scapholunate instability, triangular fibrocartilage tears, lunotriquetral ligament tears. 3. Radiographic presentation of pathology related to negative ulnar variance: Kienbock’s disease, Ulnar impingement syndrome 4. Discussion of ulnar variance, its sequelae and management.  

Ulnar variance is a common and sometimes subtle radiographic finding. It is important to be aware of the sequelae and imaging findings associated with ulnar variance pathology. This review will present key imaging findings associated with ulnar variance and discuss appropriate management.  

Kuo-Bonde, L, Masih, S, Matcuk, G, Chow, K, Ulnar Variance and Its Sequelae .  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12022705.html