Bone Abstracts

Objectives: Children who fracture have lower bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DXA) than children who do not sustain fractures, but there is little data on bone microarchitecture in relation to childhood fracture. We assessed tibia microarchitecture using high resolution peripheral quantitative computed tomography (HR-pQCT) in children with recent fracture and those without a history of fracture.

Methods: Children age >10 years with a confirmed low/moderate impact fracture in the preceding 6 months were compared to controls with no history of fracture. Distal tibia microarchitecture was assessed using HR-pQCT (XtremeCT, Scanco Medical AG, Switzerland). Standard deviation scores (SDS) for age, sex and ethnicity were calculated using published reference data (Gabel 2018 doi:10.1002/jbmr.3399) for total volumetric BMD (Tt.BMD), cortical thickness (Ct.Th), cortical volumetric BMD (Ct.BMD), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular bone volume (BV/TV). Results are presented as mean [S.D.].

Results: 33 children with fractures [F] (age 13.5 [1.6] years; 73% male) were compared with 35 non-fracturing controls [C] (mean age 13.1 [2.0] years, P=0.33; 67% male, P=0.61). Children with fracture had similar Tt.BMD SDS (1.23 [1.11]) to controls (1.05 [1.47], P=0.57). Trabecular microarchitecture was similar between the groups (Tb.Th SDS C: 0.32 [1.31] F: 0.32 [1.04], P=0.99; Tb.N SDS C: −0.01 [1.41] F: 0.14 [1.22], P=0.63; BV/TV SDS C: −0.50 [1.14] F: −0.37 [1.19], P=0.63). SDS for Ct.Th (C: 0.91 [1.68] F: 1.09 [1.21], P=0.60) and Ct.BMD (C: 3.41 [1.88], F: 3.09 [1.16], P=0.40) also did not differ. Inclusion of only children with long bone fractures (n=22) did not alter the findings, nor did analysis of boys and girls separately. 9 children with fractures had a previous confirmed fracture. Tibia microarchitecture did not differ in these children compared to those with only a single fracture (n=23) or non-fracturing controls (P>0.05 for all).

Conclusions: Bone microarchitecture at the tibia was not different in children with a recent fracture to those without a history of fracture.

Disclosure: The authors declared no competing interests.