MR imaging in chronic rupture of the ulnar collateral ligament of the thumb

Purpose: MR imaging has been shown as the best radiologic method for verify ing and classifying acute ulnar collateral ligament (UCL) ruptures of the t humb. Our aim was to analyse the usefulness of MR also in old ruptures and to establish the most useful sequences. Material and Methods: Ten patients with an old UCL rupture of the thumb wer e preoperatively imaged using 1.5 T MR. Three radiologists blinded to the f indings separately analysed the MR images of these patients and of 10 age- and sex-matched voluntary controls. MR findings of the patients were compar ed with those of surgery. Results: The consensus diagnosis of an UCL rupture was accurate in all 10 p atients. All controls were classified as having no UCL rupture. In 5 of the 7 patients with a surgically defined Stener or non-Stener lesion, the cons ensus diagnosis was the same as the operative diagnosis. Due to excessive s carring it was not possible to verify any Stener lesion intra-operatively i n 3 patients. The most informative MR sequence was T2 TSE in the coronal pl ane, the second most informative was T1 SE with fat suppression in the coro nal plane. Conclusion: An old UCL rupture is well verified by MR but typing of the les ion as either a Stener or non-Stener type is not always possible.