Underdeveloped trabecular bone microarchitecture is detected in children with cerebral palsy using high-resolution magnetic resonance imaging

Abstract

Using high resolution magnetic resonance imaging, we detected severely underdeveloped trabecular bone microarchitecture in the distal femur of children with cerebral palsy who can not ambulate independently vs. typically developing controls. Furthermore, very good short-term reliability of trabecular bone microarchitecture measurements was observed in both groups of children.

Introduction: Severe forms of cerebral palsy (CP) are associated with very low areal bone mineral density and a very high incidence of fracture in the distal femur; however, the state of trabecular bone microarchitecture has not been evaluated. Furthermore, the short-term reliability of trabecular bone microarchitecture assessment in children using high-resolution magnetic resonance imaging (MRI) has not been determined.

Methods: Apparent bone volume to total volume (appBV/TV), trabecular number, (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp) were determined in the distal femur of non-ambulatory children with CP and typically developing children using MRI.

Results: Children with CP had a 30% lower appBV/TV, a 21% lower appTb.N, a 12% lower appTb.Th and a 48% higher appTb.Sp in the distal femur than controls (n = 10/group; P < 0.001). The short-term reliability of the trabecular bone microarchitecture measures was very good, with coefficients of variation ranging from 2.0 to 3.0% in children with CP (n = 6) and 1.8 to 3.5% in control children (n = 6).

Conclusions: Underdeveloped trabecular bone microarchitecture can be detected in the distal femur of children with CP who can not ambulate independently using high-resolution MRI. Furthermore, MRI can be used to assess trabecular bone microarchitecture in children with a high degree of reliability.