Abnormality of the radioulnar joints Radioulnar dislocation UMLS:C2673394 HP:0003972 HP:0006439 A dislocation is a separation of the radius and ulna bones where they normally meet. The radioulnar joints are two locations, proximal and distal, in which the radius and ulna articulate in the forearm. Both can dislocate. This term refers to any kind of radioulnar joint dislocation (proximal, distal, both, or unknown). Dislocated radioulnar joints