Is There a Role for Bone Health Index in Assessing Bone Health in Children?

Bone imaging methods have been designed to assess bone mineral density and bone strength; however, no one modality completely analyses bone health and predicts fracture risk in children. Our systematic review and meta-analysis (Chapter 3) aimed to identify the best modality for assessing bone health in children and young people. We found that digital X-ray radiogrammetry (DXR), which measures bone health index (BHI) from hand and wrist radiographs using BoneXpert software, achieved the most robust positive correlation with DXA when compared to quantitative ultrasound (QUS) and peripheral quantitative computed tomography (pQCT).
The retrospective pilot study in Chapter 4 was conducted to investigate whether BHI values are sufficiently sensitive to distinguish between children under two years old with and without osteogenesis imperfecta (OI). We analysed the BHI and BHI SDS from 122 radiographs (33 OI, 89 suspected abuse). BHI and BHI SDS were significantly greater in the group without OI compared to the group with OI [(p = 0.003) and (p = 0.01), respectively]. Individual cut-points of sensitivity and specificity for BHI in detecting OI individuals were established.
The core of this thesis is presented in Chapters 5 through 8, detailing a prospective observational cohort study that examined correlations between BHI and high-resolution peripheral quantitative computed tomography (HR-pQCT) parameters, including finite element analysis (FEA), in healthy children and bisphosphonate-naïve patients with low bone mineral density. In total, 36 participants aged between 8 and 16 years underwent a non-dominant hand and wrist radiograph, along with an ipsilateral distal radial HR-pQCT scan on the same day. Results showed significantly higher BHI and BHI SDS in the healthy group compared to the patients (p<0.0001 and p<0.0001, respectively), with strong correlations between BHI values and most HR-pQCT parameters. BHI values showed a stronger correlation with trabecular parameters than cortical parameters throughout the study. Moreover, the strong correlation between BHI and FEA suggests that BHI may be used to predict fracture risk in children.
DXR/BHI provide valuable information about bone strength and integrity, and so it may be used as a simple method to evaluate bone health and indicate fracture risk in children and young people.