外傷性耳小骨離断の術前所見と伝音連鎖再建—アブミ骨骨折症例を中心として

Preoperative Findings and Ossicular Reconstruction in Traumatic Dislocation of Ossicular Chain

　はじめに

　外傷性耳小骨離断の多くは，頭部外傷または耳かきによる損傷でおこる。外傷性耳小骨離断の診療では，まずアブミ骨の異常の有無が大きな関心となる。アブミ骨骨折をともなうときは，キヌタ骨の変位の例に比べて内耳への侵襲が大きいと考えられるからである。しかし，本邦における外傷性耳小骨離断の報告は，キヌタ骨の変位の症例が多い^1,2）。

　本報告では，アブミ骨骨折7例を含む外傷性耳小骨離断13例の術前所見と手術成績を報告し，アブミ骨骨折を中心に，術前診断と適切な手術法などについて考察する。

In thirteen cases with dislocation of ossicular chain, 7 cases had fracture of the stapes. Preoper-ative findings were compared between the cases with and without fracture of the stapes. Bone con-duction thresholds at 2000 Hz and 4000 Hz were significantly higher in cases with fracture of the stapes.

Postoperative hearing improved in 12 cases. In two cases with fracture of the foot plate, bone conduction threshold became worse during the post-operative follow up period. In surgery, confirmation of perilymph fistula is important, and a suitable surgical method must be selected.