ステロイド長期投与中のベーチェット病患者に生じた立方骨脆弱性骨折の1例

Cuboid Insufficiency Fracture in a Patient with Behçet's Disease. Case Report

　ベーチェット病患者に生じた立方骨脆弱性骨折の1例を報告する．症例は41歳の女性で，6年前から継続的にコルヒチン0.5mg/日とプレドニゾロン10mg/日の投与を受けていた．明らかな外傷なく歩行時の右足痛が出現し，歩行困難となるも，初診時のX線像では明らかな異常は認めなかった．MRIのSTIR像で長腓骨筋腱溝に沿った線状高信号を認めたため，ステロイドによる立方骨脆弱性骨折と診断し，4週間のギプス固定と免荷後，足底装具を装着し部分荷重を開始した．発症後2カ月で疼痛は消失し，全荷重可能となった．

　A 41-year old woman with Behçet's disease (BD) complained of right midfoot pain.　She had been diagnosed with BD 6 years previously and was being treated with prednisolone 10mg/day.　The plain X-ray findings, were unremarkable, but MRI revealed a fracture line along the sulcus tendinis musculi peronei longi that was characterized by a high signal intensity change on STIR sequences.　Treatment was rest, no weight-bearing and fixation in a cast for 4 weeks, and then partial weight-bearing was allowed as tolerated with a plantar orthosis to improve midfoot support.　About 2 months after the first visit, the pain abated resolved, and an X-ray of the foot showed a sclerotic line of cuboid bone, which is characteristic of a healed trabecular stress fracture.