Portal de Periódicos da CAPES

Late-Onset Tibia Vara (Blount??s Disease)

1990; Lippincott Williams & Wilkins; Volume: 255; Issue: &NA; Linguagem: Inglês

10.1097/00003086-199006000-00004

1528-1132

George H. Thompson, JOHN R. CARTER,

Hip disorders and treatments

Idiopathic tibia vara or Blount's disease can be classified into three age-onset groups: (I) infantile, less than three years; (2) juvenile, four to ten years; and (3) adolescent, 11 years or older. The latter two groups comprise late-onset tibia vara, which is much less common than the infantileonset form. In a comparison of eight juvenileonset patients (13 knees) and seven adolescentonset patients (nine knees), there were essentially no significant clinical, roentgenographic, or physeal-histopathologic differences. Both groups had severe obesity, mild to moderate varus deformities, and less-pronounced roentgenographic characteristics. Histopathologic analyses of the entire physis from the proximal tibia in five cases (seven knees) were essentially identical in patients with the infantile form as well as in those with slipped-capital femoral epiphyses, suggesting a common etiology. Recurrence of deformity after surgical correction occurred frequently in the juvenile onset males but not in juvenile onset females or the adolescent onset group. Incomplete correction of the varus deformity occurred more frequently in the latter group. The etiology for tibia vara appears to involve varus stress growth suppression, and disruption of endochondral ossification. The major differences between the three groups is due to the age at clinical onset, the amount of remaining growth, and the magnitude of the medial compression forces across the medial aspect of the knee.