骨棘により臨床症状を呈した高齢者タナ障害の1例

Shelf Syndrome Induced by a Bony Spur of an Osteoarthrotic Knee. Case Report

　変形性膝関節症による骨棘が膝蓋内側滑膜ヒダ（タナ）に衝突（インピンジメント）し，障害を呈した症例を経験したので報告する．症例は66歳の女性．右膝痛を主訴に受診した．右膝蓋骨内側に索状物を触れ，同部に圧痛があった．痛みで端坐位で内旋位での膝伸展ができなかった．単純X線像で大腿骨内外側顆に骨棘があり，MR像で内側顆に丸く張り出した骨棘に接するタナを認め，鏡視で屈曲時にタナが骨棘に衝突（インピンジメント）し緊張することが確認できた．鏡視下にタナを中央部で切離し，症状は軽快した．

　We report a rare case of shelf syndrome induced by a bony spur of an osteoarthrotic knee. A 66-year-old woman complained of right knee pain with snapping sensation and occasional locking of the affected knee while walking. On physical examination, a band was palpated on the medial surface of the knee close to the patella. The patient was unable to extend her knee in the internally rotated position because of the associated pain. Radiographs showed osteoarthrotic changes, and MRI revealed a medial shelf adjacent to a round spur on the medial femoral condyle. Impingement of the shelf on the bony spur was confirmed by arthroscopic observation. After resecting the shelf, her symptoms were completely relieved.