Abstract
Introduction
Adolescent idiopathic scoliosis (AIS) is associated with low bone mineral density, which could be related to its etiopathogenesis. Apart from bone density, bone micro-architectures are equally important for better understanding of disease initiation and progression in AIS. Quantitative assessment of bone quality is hampered by the invasive nature of investigations, until recently when the high-resolution pQCT (XtremeCT) became available for revolutionary in-vivo microimaging and derivation of bone micro-architectural parameters. Our objective was to use this powerful instrument to study bone qualities in AIS and compare findings with those from healthy controls.
Methods
48 girls with AIS and 84 sex-matched healthy controls were recruited. Cobb angle was measured with standing radiographs, and imaging of the non-dominant distal radius was captured with XtremeCT according to a standard protocol.
Results
The mean age was 13·48 years for controls and 13·54 years for patients with AIS (p=0·773). The mean Cobb's angle for AIS was 32·7° (SD 5·8°). Volumetric bone density, cortical thickness, trabecular bone density, meta-trabecular density, inner-trabecular density, bone volume fraction, and trabecular thickness were all lower in patients with AIS than in controls, and differences were statistically significant (p<0·05).
Conclusions
This is the first report describing the differences in radiographic bone micro-architectures between patients with AIS and controls. All significant parameters were lower in the AIS group, indicating deranged bony quality that could have an important role in disease initiation or progression in AIS. The exact biomechanical process and how this is related to the etiopathogenesis of AIS warrant further studies.
Acknowledgments
This study is supported by RGC-HKSAR (project number 467808 and 468809).
