title: The association of disproportionate skeletal growth and abnormal radius dimension ratio with curve severity in adolescent idiopathic scoliosis.
abstract: Abnormal anthropometric measurements during the peripubertal growth spurt have been documented in adolescent idiopathic scoliosis (AIS). Magnetic resonance (MR) imaging studies of the spine have suggested a disproportionate endochondral and membranous ossification in AIS. The present study aimed at investigating whether disproportional ossification and skeletal growth occurred in the peripheral bone of AIS patients using the radius as the target bone. Skeletally mature AIS girls with different severity (n = 290) and age-matched control healthy girls (n = 80) were recruited. The anthropometric parameters were recorded. The midshaft of non-dominant radius was scanned with peripheral quantitative computed tomography (pQCT) and the radius diameter was calculated from the cross-sectional area. Radius dimension ratio was derived from the ratio of radius diameter to radius length. The anthropometric parameters were compared between AIS and control with adjustment for age. The radius dimension ratio was further correlated with curve severity in AIS girls using Pearson's correlation test. The analysis showed that the arm span and radius length were slightly longer in AIS girls. The BMI of AIS girls was significantly lower than the controls. The radius dimension ratio in severe AIS girls was significantly lower than the controls and the ratio of AIS girls correlated with the curve severity (r = -0.120; p = 0.039). The abnormal radius dimension ratio supported the presence of systemic growth abnormalities in AIS. Disproportional endochondral-membranous ossification could explain for the observation. The observation of the association of radius dimension ratio with curve severity provides an important potentially clinically measurable parameter for further longitudinal studies on the prognostication of curve progression in AIS.
authors.affiliation: Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, 5/F, Clinical Science Building, Shatin, NT, Hong Kong SAR, China.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Wang
authors.forename: Vivian Wing-Yin
authors.initials: VW
authors.lastname: Hung
authors.forename: Tsz-Ping
authors.initials: TP
authors.lastname: Lam
authors.forename: Bobby Kin-Wah
authors.initials: BK
authors.lastname: Ng
authors.forename: Ling
authors.initials: L
authors.lastname: Qin
authors.forename: Kwong-Man
authors.initials: KM
authors.lastname: Lee
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
authors.forename: Jack Chun Yiu
authors.initials: JC
authors.lastname: Cheng
authors.forename: Hiu Yan
authors.initials: HY
authors.lastname: Yeung
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D015992:Body Mass Index; D001846:Bone Development; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D011859:Radiography; D011884:Radius / Q000000981:diagnostic imaging / Q000254:growth & development*; D012600:Scoliosis / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D055815:Young Adult