US of the anterior bundle of the ulnar collateral ligament: findings in five cadaver elbows with MR arthrographic and anatomic comparison--initial observations.
OBJECTIVE
To characterize the ultrasonographic (US) appearance of the anterior bundle of the ulnar collateral ligament of the elbow by comparing US images with magnetic resonance (MR) arthrograms and anatomic slices.


METHODS
The ulnar collateral ligament in four cadavers (eight elbows) was blindly evaluated with US by one musculoskeletal radiologist with experience in musculoskeletal US. These results were compared with standard arthrograms, MR arthrograms, and anatomic slices by consensus reading of two musculoskeletal radiologists. The criteria for an abnormal ulnar collateral ligament included contrast material extension into the ligament or fiber discontinuity, as documented by MR arthrography and anatomic slices.


RESULTS
Standard arthrography, MR arthrography, and anatomic slices demonstrated the ulnar collateral ligament to be unequivocally normal in three specimens and abnormal in two. The remaining three elbows did not meet the criteria for classification as either normal or abnormal, and thus they were excluded from the study. With US, the normal ulnar collateral ligament was fibrillar and hyperechoic between the medial epicondyle and proximal ulna. In the two abnormal cases, abnormal hypoechogenicity and ligament fiber disruption were noted. In addition, the proximal aspect of the ulnar collateral ligament varied from a cordlike structure to a broad attachment to the undersurface of the medial epicondyle with variable fat.


CONCLUSIONS
In this small sample, the anterior bundle of the ulnar collateral ligament is identified with US by its hyperechoic and compact fibrillar echotexture. The proximal attachment of the ulnar collateral ligament has a variable appearance. Hypoechogenicity and fiber disruption indicated ulnar collateral ligament abnormality.
Department of Radiology, University of Michigan Medical Center, 1500 E Medical Center Dr, TC-2910G, Ann Arbor 48109-0326, USA. jjacobsn@umich.edu
Jon A
JA
Jacobson
Tim
T
Propeck
David A
DA
Jamadar
Peter J L
PJ
Jebson
Curtis W
CW
Hayes
D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography / Q000379:methods*; D002102:Cadaver; D017885:Collateral Ligaments / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D004551:Elbow Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014457:Ulna; D014463:Ultrasonography