モートン病

Morton's Disease

モートン病は偽神経腫を伴う中足骨頭間における底側趾神経障害である。中年以降の女性に多く，発症部位は第3趾間が最も多い。モートン病は同部における神経の絞扼や微細な外傷の繰り返しが主な病因と考えられ，偽神経腫は二次的変化と考えられている。保存的治療は，靴の指導，足底挿板およびステロイドと局所麻酔の注射により行う。保存的治療で改善が不十分な場合は，神経切除術などの手術的治療が施行される。

Abstract

Morton's disease refers to neuralgia at the web space of the toes with a pseudo-neuroma. It commonly occurs in the third web space of the foot in middle-aged and older women. The pseudo-neuroma is thought to be a secondary change after entrapment or repeated microtrauma. Patients complain of forefoot pain while walking. Typically, symptoms are caused by tight high-heeled shoes. The physical examination includes palpation of the web spaces and Mulder's test. Weight bearing foot radiographs are used to evaluate the deformity of the foot, especially at metatarsophalangeal (MTP) joints. MRI is useful for differential diagnosis of pseudo-neuroma, MTP joint arthritis, and interdigital bursitis. Conservative treatments are shoe modification, use of orthotic insoles, and injection of corticosteroids and local anesthesia. The injections are useful not only for the treatment but also for diagnosis of Morton's disease. If the local injection is not temporally effective, surgical treatment is not indicated. If the conservative treatment fails, surgical treatment is indicated. The most common surgery is excision of the pseudo-neuroma. The surgery is usually performed using a dorsal approach.