矯正骨切り術とイリザロフ創外固定器による仮骨延長術を併用した示指斜指症の1例

Opening Wedge Osteotomy and Callus Distraction with the Ilizarov Minifixator for Index Finger Clinodactyly

はじめに

　斜指症は指節骨が台形あるいは三角形の形態異常を呈し，10°以上の側屈偏位しているものと定義されている 1）。斜指症の多くは治療の対象にはならないが，整容目的に矯正骨切り術や骨端核部分切除術が行われる 2）。しかし，側屈偏位が強く短縮を伴う斜指症では術後に偏位が残存し短指が助長する恐れがある。今回われわれは矯正骨切り術にイリザロフ創外固定器（アラタ社）による仮骨延長術を組み合わせ，良好な結果が得られた症例を経験したため文献的考察を加えて報告する。

　Clinodactyly is defined as a deviation of a digit in the coronal plane. It is treated mainly by a corrective osteotomy or a partial resection of the epiphysis. A closing wedge osteotomy is the simplest procedure and can provide excellent correction of clinodactyly, but its use further shortens the deviated and shortened digit. We report a case in which the combination of an opening osteotomy and callus distraction using the Ilizarov minifixator was used, with excellent results.

　The patient was a 5-year-old boy with clinodactyly in his left index finger. The radial deviation of the proximal phalanx was 31.8°, and the length was shortened by 7.2 mm from the healthy side. A corrective osteotomy with the Ilizarov minifixator was performed with the patient under general anesthesia. Distraction was done at a rate of 0.5 mm/day for a total of 7.5 mm, and the external fixator was removed 89 days after the surgery (Healing index: 108.5 day/cm). Postoperatively, range-of-motion exercises were performed and good morphology was obtained.

　The Ilizarov minifixator uses steel wires that are easy to insert into small bones, which has been difficult with a conventional external fixator. Although this method is technically complicated and places a significant burden on the patient, including the period wearing the external fixator, it enables the ideal correction of the finger axis and bone lengthening.