Source:  ULNAR DIMELIA (MIRROR HAND SYNDROME)    Tag:  ulna artery
Ulnar dimelia ("mirror hand") is a rare congenital anomaly of the upper extremity characterized by duplication of the ulna, absence of the radial ray, and polydactyly. A case report is presented in which the patient had eight triphalangeal digits arranged in a two clusters of four each. It does not have any known association with any multisystem organ anomaly and usually seen to occur in isolation. Bilateral cases have not been reported.
We received a 7yrs old female child for evaluation of polydactyly and to assess elbow joint anatomy.

There is duplication of ulna noted with absence of radius.
The lower end of humerus appears widened with well formed trochlea. Capitulum is not seen.
Olecranon process of both ulna are not seen to articulate with the trochlea. They are seen on the either side of condylar region of humerus.
Polydactyly noted with duplication of 2nd to 5th fingers (metacarpal, proximal, mid and distal phalanges) and absence of thumb. The duplication pattern is in mirror image like symmetry.
There are two sets of five carpal bones symmetrically placed at the wrist joint – capitate hamate, triquetral, lunate and trapezoid.
Scaphoid, trapezium and pisiform are absent.
There is symmetric duplication of the ulnar artery noted. Further two sets of muscle/ tendons seen for flexor digitorum muscles (superficialis and profundus).
Duplication of ulna and five carpal bones – capitate, hamate, triquetral lunate and trapezoid, duplication of metacarpals and phalanges of 2nd to 5th finger in mirror like symmetry.