有痛性尺骨茎状突起骨核融合不全の1例

Painful Unfused Separate Ossification Center of the Ulnar Styloid : Case Report

　抄録：有痛性尺骨茎状突起骨核融合不全（Painful unfused separate ossification center of the ulnar styloid）の1例を経験した．28歳，男性で，約1年前より明らかな外傷歴なく，左手関節尺側に疼痛が出現し，徐々に増強し，仕事に支障をきたすようになった．初診時，左手関節尺骨茎状突起部に圧痛を認め，手関節背屈で手関節尺側に疼痛を訴えたが，可動域制限はなかった．単純X線像で尺骨茎状突起基部の偽関節様像を認めた．骨片は丸く辺縁は滑らかであった．透視下にリドカインによる尺骨茎状突起基部の間隙への浸潤麻酔試験で疼痛は消失した．骨移植のうえ，tension band wiringを施行し，術後3カ月で骨癒合を獲得した．左手関節痛は完全に消失し，原職に復帰した．Unfused separate ossification center of the ulnar styloidは稀な状態であるが，手関節の疼痛や機能障害の原因になりうる．

　The patient was a 28-year-old male engineer with no clear history of trauma who had begun to experience pain in the ulnar portion of his left wrist about one year proviously. He came to our clinic because the pain had become more severe during work over approximately the past three months. Radiographs showed an unfused separate ossification center of the ulnar styloid process. The pain resolved completely in response to local injection of lidocain in to the gap between the separate process and the ulna, and tension band wiring combined with a bone graft of the ulnar styloid process was performed. The pain subsequently resolved, and the patient returned to work without limitation of the range of motion of his wrist joint. An unfused separate ossification center of the ulnar styloid is a rare occurrence, and only one case associated with pain has ever been reported. Unfused separate ossification centers of the ulnar styloid can be a cause of pain and impaired function.