EBI® DynaFix® Systemを用いて治療したBlount病の1例

Treatment of Juvenile Blount's Disease with EBI® DynaFix® System. Case Report

　Juvenile typeのBlount病の1例を経験した．症例は初診時8歳の女児で，脚長差2.5cm，Langenskiöld分類stageⅣ，大腿脛骨角（FTA）195°であった．初回手術ではOrthofix創外固定器を用いて矯正したが再発した．再手術時（11歳），脚長差2.6cm，FTA 199°で，EBI^® DynaFix^® Systemを用いて骨延長を行いつつ脛骨の内反変形を徐々に矯正した．再手術後3年の現在，身長増加は停止しており，脚長差0.7cm，FTA 177°で疼痛，跛行も認めておらず，経過は良好である．

　We treated a case of juvenile Blount's disease. The patient was an 8-year-old girl who came to our hospital with varus deformity and recurvatum of the left knee and a 2.5cm in leg-length discrepancy after being treated conservatively for one year. The femorotibial angle (FTA) was 195°, and the recurvatum deformity was 20°. The varus deformity and recurvatum were corrected with an Orthofix external fixator, but the varus deformity (FTA, 199°) and leg-length discrepancy (2.6cm) gradually recurred. In the second operation the EBI^® DynaFix^® system was used and allowed simultaneous correction of the varus deformity and lengthening of the limb. The postoperative clinical course has been satisfactory. The EBI^® DynaFix^® system seems more useful in terms of daily life activities, because it is lighter and smaller than the Ilizarov system. Moreover, it is easy to assemble, and there is less risk of neurovascular injury, because half-pins are usually used during the operation.