Bilateral, asymmetrical congenital dislocation of the radial heads in trisomy 8 syndrome.

Congenital radial head dislocation (CRHD) can occur as an isolated abnormality, as part of an upper-limb anomaly or as a feature of at least fourteen syndromes. The dislocation may be unilateral or bilateral, and rarely can be bilaterally asymmetrical. CRHD is often asymptomatic, and may go undiagnosed and remain undetected until after a radiography has been obtained for an incidental injury. It is therefore important to be able to differentiate congenital from traumatic dislocation of the radial head. We report a mentally retarded female, known to have trisomy 8, who presented with stiffness of her elbow joints and no history of preceding trauma. Radiographs confirmed bilateral asymmetrical radial head dislocation. This combination of anterior and posterior CRHD co-existing in the same patient has not been described previously with trisomy 8 syndrome.