Table 2.

Characteristics of echographic examinations.

Characteristics	Study population (N = 55)
Age (days) at the time of the first echography, median (IQR)	79 (17)
Right hip alpha angle, mean (SD)	65.58 (5.52)
Right hip beta angle, mean (SD)	52.2 (5.75)
Right hip Graf classification, n (%)
1a	38 (69.1%)
1b	17 (30.9%)
Left hip alpha angle, mean (SD)	66.33 (5.65)
Left hip beta angle, mean (SD)	50.45 (6.62)
Left hip Graf classification, n (%)
1a	45 (81.8%)
1b	10 (18.2%)