Presentation
Assessment of polydactyly.
Patient Data
![](https://prod-images-static.radiopaedia.org/images/4502288/13ed58fd616df72292420e84b036b2_big_gallery.jpg)
As demonstrated clinically, there are too many fingers. However, there is a little more to this case. There are two sets of middle, ring and little fingers symmetrically centered around the central ray that has duplicated middle and distal phalanges.
Features here suggest partial ulnar duplication.
![](https://prod-images-static.radiopaedia.org/images/4478598/bfbb81d71e757b5db5a998ab318ac5_thumb.jpg)
![This study is a stack](/packs/stack-YQKLCKBI.gif)
![](https://prod-images-static.radiopaedia.org/images/4478746/9775ade854936c238cdf51683f8f96_thumb.jpg)
![This study is a stack](/packs/stack-YQKLCKBI.gif)
![](https://prod-images-static.radiopaedia.org/images/4479395/ae81a938dc33175a476e1965b5f55c_thumb.jpg)
![This study is a stack](/packs/stack-YQKLCKBI.gif)
![](https://prod-images-static.radiopaedia.org/images/4478598/bfbb81d71e757b5db5a998ab318ac5_big_gallery.jpg)
CT confirms that there is ulnar duplication with symmetry of the carpals and artery system.
![](https://prod-images-static.radiopaedia.org/images/4478809/69d166a13bbb5014792d5da5880b68_big_gallery.jpg)
MRI of the elbow confirmed that the elbow articulation as formed by a single humerus and two ulna.
Case Discussion
Ulnar dimelia (or mirror hand) is a rare congenital abnormality where there is duplication of the ulna and mirroring of the lateral rays and carpals.