浮遊母指温存を希望された母指形成不全Blauth分類4型の1例

A Case of Hypoplastic Thumb Classified as Blauth Type 4 with a Request for Floating Thumb Preservation

はじめに

　母指形成不全は手の先天異常分類において橈側列形成障害の部分症として位置づけられており，Blauth分類により5型に，Manskeらの分類により6型に分類され，その重症度に応じた治療方針が確立されつつある 1）2）。Manske分類3b型，4型の場合，低形成で機能的改善に乏しい母指が存在し，この母指を温存するのか，母指化術を行うのか，機能・整容面について十分な説明を行ったうえで家族と治療方針を決定する必要がある。

　今回，浮遊母指温存を強く希望された母指形成不全Blauth分類4型の1例を経験し10年の経過を追ったため，若干の文献的考察を含めて報告する。

　We experienced a case of thumb hypoplasia classified as Blauth type 4, in which the parents requested preservation of the floating thumb. Although thumb reconstruction (pollicization) is generally recommended for Type 3b and 4 due to functional considerations, some families prefer to maintain five fingers for aesthetic reasons. Therefore, it is essential to thoroughly explain both the functional and cosmetic outcomes before determining the treatment plan. A treatment that aims to achieve a balance between both function and appearance, but this case was unique in that due to the familyʼs strong wish, sufficient functional reconstruction could not be performed. Nevertheless, the patient is currently satisfied with the cosmetic outcome and does not experience inconvenience in daily life, nor does the family wish for further functional reconstruction. However, we would like to continue following the childʼs growth and consider appropriate treatment interventions as needed.