Evolution of head-shaft angle and neck-shaft angle in childhood

Abstract

The current retrospective study investigates the natural evolution of head-shaft angle (HSA) and neck-shaft angle (NSA) in childhood. It is not known if a high HSA in early childhood leads to a high HSA in adulthood. This study aims to characterize the evolution of HSA and compares it with the more commonly known NSA in healthy children. We measured radiographs of 84 different healthy hips of children between 3 and 14.5 years old who underwent at least 2 radiographs of the pelvis, corresponding to 286 measurements. We used a linear mixed model to determine the covariance between random intercept and slope while allowing each individual hip to change over time. The covariance for HSA between random intercept and random slope was -4.262 (p < 0.001), corresponding to a high negative correlation of -0.717, for NSA -2.754 (p = 0.031) or a high negative correlation of -0.779. HSA and NSA were strongly correlated, a value of 0.736 (p < 0.001) was measured. The high negative correlation for random intercept and random slope means that the higher the initial value (intercept), the steeper the decline (slope). Therefore HSA decreases faster in hips with high HSA at an early age. Hips with high HSA in early childhood do not necessarily lead to hips with high HSA in adulthood. Our results may aid in future clinical decision making in patients with developmental dysplasia of the hip (DDH) with high HSA in particular.

Effects of hip brace on coxa valga in nonambulatory children with cerebral palsy: A randomized controlled trial

“…Non-CP children with high NSA and HSA at age 3 years old showed a continuous decrease in angles (average decrement in NSA, −1.1°/year [95% CI: −1.5 to −0.8°/year]; in HSA, −1.1°/year [95% CI: −1.5 to − 0.7°/year]). [ 21 ] One study comparing the evolution of the HSA in CP and non-CP children showed that the HSA of non-CP children and ambulatory CP children (GMFCS levels II and III) decreased between 2 and 8 years of age. In contrast, the HSA of nonambulatory children with CP (GMFCS levels IV and V) did not show a decrement as they grew over the same period.…”

Imaging of Disease and Normal Variant Patterns in Pediatric Hips

“…15 Of note, the neck-shaft angle in children does change with age. Van Geel et al 16 investigated the evolution of head-shaft angle (HSA) and neck-shaft angles during childhood. They found a high negative correlation for HSA between the initial measurement and the rate of change over time, indicating that a larger angle during the early years is predictive of a faster decrease in that angle through adolescence.…”

“…They found a high negative correlation for HSA between the initial measurement and the rate of change over time, indicating that a larger angle during the early years is predictive of a faster decrease in that angle through adolescence. 16 The mean age of the 286 measurements for 84 different measured hips was 7.4 years (standard deviation [SD]: 2.9). The HSA ranged from 133.8 to 177.8 degrees with a mean of 154.1 degrees (SD: 7.2).…”