Clinicoradiological study of the leg appearance in normal infants below one year

ABSTRACT

The physiological curve of the legs seen in the majority of infants as a lateral convex curve from knee to ankle is a great worry to parents. Eighty normal infants below one year were subjected to clinical and radiological study of their legs to assess if the bow involves bone and/or soft tissues. They were divided into three groups to see the effect of growth and age on the curve [group I from 0-<4 months, group II from 4-<8 months and group III from 8-<12 months]. The degree of curvature of the soft tissues as well as the bones were measured geometrically. The mean degree of curvature of soft tissues in the three studied groups was 7.196m-1 in group I, 6.43 m-1 in group II and 4.4 m-1 in group III and the mean degree of bone curvature was 3.7 m-1, 2.9 m-P and 1.9 m-1 in group I, group II and group III respectively. It was apparent from our study that the mean degree of soft tissues curvature was significantly higher than the mean degree of bone curvature and that the degree of curvature of both soft tissues and bone decreases significantly with age i.e. throughout growth. In conclusion, the main cause of the physiological curve is the lateral bulge of the soft tissues of the calves. This could be related to crossing of the legs early during the intra-uterine life which is expected to exert pressure on the medial sides of both legs and this pressure will be increased towards term. This pressure is expected also to deviate the growing calf muscles laterally and to interfere with deposition of fat on the medial sides allowing excess deposition of fat on the lateral sides. As to the tibias, Their rapid growth occurs earlier before the occurrence of significant crossing of the legs. However, crossing is assumed to exert some pressure resulting in mild bowing. After birth, the crossing pressure will be nullified and the continuing growth of the infant will correct all the deviation