HIP DEVELOPMENT IN CHILDREN : ACETABULAR INDEX (AI) AND PHYSEAL ANGLE (ALSBERG’ ANGLE) OF PROXIMAL FEMUR IN CHILDREN OF 1, 2 AND 3 YEARS

Abstract

Purpose: To study the development of the hip and the relationship of radiological angles between acetabulum and proximal femur in children 0–3 years and thus the influence of walking and weight bearing on hip development.

Material and Methods: A study mesuring radiological angles in antero-posterior X-rays of pelvis in 334 children between 0 a 3 years of age (1997–2005), including acetabular index (AI) and physeal proximal angle (PPA (Alsberg’ angle) with goniometer (error ± 1°). Patients with pelvis or femur fractures or inflammatory diseases were excluded. Age distribution was of 1 (69.2%), 2 (22.2%) and 3 years (8.7%). 36.8% were males and 63.2% females. Descriptive statistics, T- test, Spearman correlation and ANOVA were used. Level of significance p< 0.05.

Results: The mean AI was 20.2°, 19.9° and 17.3°, in 1, 2 and 3 years. The AI angle diminishes significatively in children older than 2 years of age (p = 0.002). The mean PPA was 79.5°, 74.9° and 74.2°, in 1,2 y 3 years respectively. The Alberg’s angle reduced significatively at 1 year of age (p = 0.0005). AI and PPA was higher in females after 1 year of age (p = 0.02 and p = 0.04). There are not significative correlation between AI and Alsberg’ angle in different groups of children (r = 0.03). The age was important factor in both angles changes (p = 0.0005), but female patients (p = 0.002) and left side (p = 0.02) influenced only in AI.

Conclusions: AI and PPA angles reduced with age specially in 2 and 1 year, respectively, suggesting the effect of weight bearing and walking on hip shape. There was not relation between both angles in different groups of age.