小児にみられた遠位撓尺関節背側亜脱臼の2症例

抄録

Two cases of traumatic subluxation of the distal radio-ulnar joint were reported. The patients, aged six and nine, fell down with out-stretched hand but precise mechanism of the injury was not known. On examination, the wrist was held in slight pronation and there was slight prominence of the ulnar head. Swelling about the wrist was scarcely detectable. There was slight pain, much increased by attempt to supinate the forearm. There was full movement of the radio-carpal, fingers and elbow joint. Anteroposterior laxity of the distal radioulnar joint could be demonstrated by manipulation. Radiograms did not show any abnormality. The ulnar head was reduced with a palpable click easily by direct pressure over it in pronation. But when the pressure took off, the ulnar head subluxated dorsally again, whereas the wrist was stable after reduction in supination. The wrist was immobilized in an aboveelbow plaster with forearm in maximum supination. Immobilization was continued for three weeks. A week after removal of the plaster full range of motion of the forearm and wrist has been recovered and there was no instability of the distal radio-ulnar joint. The authors thought that these cases were dorsal subluxation of the radio-ulnar joint by a probable hyperpronation injury.