adverse reactions to metal debris（ARMD）による偽腫瘍と考えられた左股関節巨大溶骨性腫瘤の1例

A case of huge pseudotumor caused by adverse reactions to metal debris in hip replacement

adverse reactions to metal debris（ARMD）とは，臼蓋側と骨頭側がともに金属製（metal-on-metal：MoM）の人工関節を用いた全人工股関節置換術後に発生する合併症で，術後の疼痛や骨融解，インプラント周囲の偽腫瘍などを生じる一連の病態である。今回我々は，ARMDによる偽腫瘍と思われた左股関節に生じた巨大溶骨性腫瘤の1例を経験したので文献的考察をふまえて報告する。

A 70s-year-old male presented with left hip pain. He had undergone a metal on metal hip replacement over 20 years ago. CT revealed a huge mass around the left hip joint. The mass extended the acetabular and the proximal femur, and the implant was compressed outwardly. Biopsy revealed no malignancy and the mass had no change for two years. The mass was thought a pseudotumor caused by adverse reactions to metal debris.