Introduction: Disproportionate endochondral and membranous ossification in adolescent idiopathic scoliosis (AIS) has been suggested in the axial skeleton. It is also generally accepted that the AIS girls are taller than their healthy peers.
Objectives: To investigate whether disproportional skeletal growth occurred in the peripheral bone of AIS patients.
Subjects and Methods: Skeletally mature AIS girls (n=290) were recruited together with age-matched healthy girls(n=80) as normal control. The anthropometric parameters were recorded. The midshaft of non-dominant radius was scanned with peripheral quantitative computed tomography (pQCT) and the radius width was calculated from the cross-sectional area. Radius geometry ratio was derived from the ratio of radius width to radius length. The anthropometric parameters were compared between AIS and control with adjustment for age. The radius geometry ratio was correlated with curve severity in AIS girls.
Results: The arm span and radius length were longer in AIS girls. The BMI of AIS girls was significantly lower than the controls. The radius geometry, in severe AIS girls was significantly lower than the controls and was found to correlate with the curve severity (r=-0.120; p=0.039).
Conclusion: The abnormal radius geometry ratio supported the previous finding on disproportional endochondral ossification vs. membranous ossification. The disproportionate radial growth was also found to be positively associated with the curve severity of AIS girls. The regulatory mechanism of endochondral and membranous ossification in AIS subjects should be warranted further study.
Significance: The present study provided additional piece of evidence for the role of skeletal growth in the development of AIS.