[Tibia vara in adolescents. Apropos of 19 cases].

OBJECTIVE

Clinical, and radiological aspects and treatment of adolescent tibia have been studied in a review of 19 children native of the Caribbean.

METHODS

23 cases of adolescent tibia vara in 19 children have been collected (14 males and 5 females, aged from 9 to 14).

METHODS

Clinical aspects (weight, lower limb axis), radiological signs (aspect of the physis, mechanical axis, epiphyseal slope) were studied pre and post-operatively.

RESULTS

All the boys presented an important overweight. Pain was the first symptom, characterized by a progressive varus deformity on a leg which was previously straight. Radiological findings consisted in metaphyseal varus and widening of the medial part of the physis. Mechanical femoro-tibial axis varied from 10 degrees to 55 degrees varus, medial epiphyseal slope from 12 degrees to 30 degrees. Average mechanical femoral angle was 92 degrees and accounted for a mean femoral varus deformity of 4 degrees. 23 knees were operated, 4 after fusion of the whole physis. 10 lateral hemi-epiphysiodesis were performed with a mean correction of 4 degrees every year until fusion. In 3 cases a tibial osteotomy was made in a second time, at the end of growth. In 6 cases of late treated patients, an isolated tibial osteotomy of valgisation was performed. In 7 cases of important deformity before closure of the physis, tibial osteotomy was associated with lateral epiphysiodesis. In one case, a lateral closing wedge osteotomy was performed, associated to an elevation of the medial tibial plateau and a lateral hemi-epiphysiodesis.

CONCLUSIONS

Histopathological examination of the physis showed similarities between adolescent tibia vara, infantile tibia vara and Slipped capital femoral epiphysis: the entire physeal plate was involved. Concerning pathogenesis of adolescent tibia vara, mechanical factors are predominant, with abnormal pressures across the medial part of the physis.

CONCLUSIONS

Adolescent tibia vara occur in obese black children and can be considered as an epiphysiolysis of the upper end of the tibia.