[Radiologic morphometry of the hip in Beninese black children]

The author aims to objectivize simple parameters of normal anatomy of the hip related to age and sex in children as a contribution to interpretation criterions in medical imagery. Materials and methods. He has examined antero-posterior radiographs of 155 normal hips (right: 81; left: 74) among 129 children aged from six months to 16 years (mean age=8.9 years). They were 86 boys and 43 girls (ratio M/F=2).

The results are as follow:--the joint space of the hip (JS/H): cranial part (cranial joint space: CJS/H): 5.5 mm +/- 0.5; medial part (medial joint space: MJS/H): 7 mm+/-0.5; --the bony roofingless part of the femoral head (BR/FH): 1-6 years: 1-3 mm; 7-13 years: 4-5 mm; 14-16 years: 6 mm; --the neck shaft angle of the femur (NSA/F); 1-6 years: 150 degrees-140 degrees; 7-16 years: 135 degrees; --the horizontal and the vertical diameters of the femoral head (HD/FH; VD/FH); x being the age of the children, the HD/FH grows according to a linear regression function as Ydh = 2x + 13+/-2 and the VD/FH as Ych = 2x + 18+/-2; --the centre acetabular edge index (CEI): the CEI decreases from 1 to 16 years: medium: 2.75-1.77; maximum: 2.31-1.67; minimum: 3.62-1.91; --the centre-acetabular cartilage index (CCI)): the CCI grows from 1 to 16 years: medium: 0.57-0.70; maximum: 0.62-0.73; minimum: 0.5-0.68. No influence of the side of the hip nor the sex of the children is observed.

This study brings out exhaustive and original data on the growth velocity of the hip skeleton in children and supplies with criterions of diagnosis according to age in childhood.