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Background: Adolescent idiopathic scoliosis (AIS) patients have lower physical activity levels than normal adolescents, and there is an association with poorer bone and muscle health. This study evaluated the effects of a home-based exercise intervention (E-Fit) on bone mineral density (BMD), muscle function, and quality of life (QoL) in AIS-affected girls., Methods: A total of 40 AIS females aged 11 to 14 years were randomly assigned to the E-Fit or control group. The E-Fit group performed modified 7-min high-intensity interval training (HIIT) 5 days per week for 6 months. Outcome measures including BMD using dual-energy X-ray absorptiometry (DXA), muscle strength and endurance tests, physical activity levels, and QoL using self-reported questionnaires were assessed at baseline and at 6-month and 12-month follow-up., Results: In total, 14 patients in the E-Fit and 16 in the control group completed the study. The E-Fit group showed a marginally significant interaction effect in the whole body areal BMD at the 6- ( p = 0.096) and 12-month follow-ups ( p = 0.085). The left arm lean mass in the E-Fit group showed a statistically significant interaction effect between the 6- and 12-month follow-ups ( p = 0.046). The E-Fit group showed improvements in physical activity participation, as measured by the Modified Baecke Questionnaire (MBQ), with a significant interaction effect in work index ( p = 0.043), sport index ( p = 0.050), and total score ( p = 0.016) from baseline to the 12-month follow-up. Improvement on self-image were noted in E-Fit group across time., Conclusions: The present results provided some evidence to support the positive benefits of E-Fit for bone health and muscle function in AIS girls.

Purpose: Osteopenia has been widely reported in about 30 % of girls with adolescent idiopathic scoliosis (AIS). However, the bone quality profile of the 70 % non-osteopenic AIS defined by areal bone mineral density (BMD) with conventional dual-energy X-ray absorptiometry (DXA) has not been adequately studied. Our purpose was to verify whether abnormal volumetric BMD (vBMD) and bone structure (morphometry and micro-architecture) also existed in the non-osteopenic AIS when compared with matched controls using both DXA and high-resolution peripheral computed tomography (HR-pQCT)., Methods: This was a case-control cross-sectional study. 257 AIS girls with a mean age of 12.7 (SD = 0.8) years old and 187 age- and gender-matched normal controls with an average age of 12.9 (SD = 0.5) years old were included. Areal BMD (aBMD) and bone quality were measured with standard DXA and HR-pQCT, respectively. The parameters of HR-pQCT could be categorized as bone morphometry, vBMD and bone micro-architecture. The results were compared between the osteopenic AIS and osteopenic control, and between the non-osteopenic AIS and non-osteopenic control., Results: In addition to the lower aBMD and vBMD, osteopenic AIS showed significantly greater cortical perimeter and trabecular area than the osteopenic control even after adjustments of age (P < 0.05). Non-osteopenic AIS also showed significantly lower aBMD together with lower cortical area, thickness and vBMD than the non-osteopenic control (P < 0.05). After adjustments of age, cortical area and vBMD, and trabecular number and separation continued to show statistical significance (P < 0.05). Both the osteopenic and non-osteopenic AIS subgroups revealed significant abnormal bone quality parameters from that in the control group after adjustments of age and aBMD with multi-linear regression analysis (P < 0.05)., Conclusions: The present study specifically defined the abnormal profile of bone quality in the osteopenic and non-osteopenic AIS for the first time. Both the osteopenic and non-osteopenic AIS were likely to have relatively lower bone mineral status and abnormal bone morphometry, micro-architecture and volumetric density profile compared with their normal matched controls. The observed abnormalities were suggestive of decreased endocortical bone apposition or active endocortical resorption that could affect the mechanical bone strength in AIS. The underlying pathomechanism might be attributed to abnormal bone modeling/remodeling that could be associated with the etiopathogenesis of AIS.

Background Context: Adolescent idiopathic scoliosis (AIS) is associated with low bone mass that could persist into early adulthood and is an important prognostic factor for curve progression. Previous studies were confined to areal bone mineral density measurement that was a two-dimensional investigation for a three-dimensional structure. Evaluation of volumetric BMD (vBMD) and other bone quality parameters are important for gaining in-depth understanding of the etiopathogenesis of AIS., Purpose: The objective of this study was to carry out direct in vivo measurement of bone quality in AIS using high-resolution peripheral quantitative computed tomography (HR-pQCT) and compare the correlation of bone quality with osteopenia between AIS and control subjects., Study Design/setting: A case-control study., Patient Sample: Newly diagnosed AIS girls (n=112) and non-AIS girls (n=115) between 11 and 13 years., Outcome Measures: Areal bone mineral density of bilateral femoral necks and HR-pQCT of the nondominant distal radius were performed., Methods: Areal bone mineral density of femoral necks was measured by dual-energy X-ray absorptiometry. Subjects were classified into the osteopenic (Z score less than or equal to -1) and nonosteopenic (Z score more than -1) groups. Bone quality parameters, including bone morphometry, trabecular bone microarchitecture, and vBMD, were measured by HR-pQCT (XtremeCT; Scanco Medical, Zurich, Switzerland)., Results: In AIS, the osteopenic group had lower measurements in cortical area, cortical thickness, average vBMD, compact bone vBMD, trabecular vBMD, trabecular bone volume to tissue volume ratio, and trabecular thickness compared with nonosteopenic AIS subjects. In contrast, among the non-AIS controls, the osteopenic group had lower measurements only in bone morphometry, average vBMD, and compact bone vBMD but not in trabecular vBMD and all other trabecular bone microarchitecture parameters., Conclusions: This is the first study using HR-pQCT to compare the correlation of bone quality with osteopenia in AIS and non-AIS subjects. It provides new insights and highlights the unique bone quality profile with predominant changes in the trabecular compartment in association with osteopenia being notably only detected in the AIS subjects. Further studies in this area are warranted for defining the metabolic nature and biomechanical sequelae of derangement in bone mass and bone quality and their roles in the etiopathogenesis of AIS., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Unlabelled: The aim of this randomized controlled trial was to determine whether whole body vibration (WBV) therapy was effective for treating osteopenia in adolescent idiopathic scoliosis (AIS) patients. Results showed that WBV was effective for improving areal bone mineral density (aBMD) at the femoral neck of the dominant side and lumbar spine BMC in AIS subjects., Introduction: AIS is associated with osteopenia. Although WBV was shown to have skeletal anabolic effects in animal studies, its effect on AIS subjects remained unknown. The objective of this study was to determine whether WBV could improve bone mineral density (BMD) and bone quality for osteopenia in AIS subjects., Methods: This was a randomized, controlled trial recruiting 149 AIS girls between 15 and 25 years old and with bone mineral density (BMD) Z-scores <-1. They were randomly assigned to the Treatment or Control groups. The Treatment group (n = 61) stood on a low-magnitude high-frequency WBV platform 20 min/day, 5 days/week for 12 months. The Control group (n = 63) received observation alone. Bone measurement was done at baseline and at 12 months: (1) aBMD and BMC at femoral necks and lumbar spine using dual-energy X-ray absorptiometry (DXA) and (2) bone quality including bone morphometry, volumetric BMD (vBMD), and trabecular bone microarchitecture using high-resolution peripheral quantitative computed tomography (HR-pQCT) for nondominant distal radius and bilateral distal tibiae., Results: The Treatment group had numerically greater increases in all DXA parameters with a statistically significant difference being detected for the absolute and percentage increases in femoral neck aBMD at the dominant leg (0.015 (SD = 0.031)g/cm(2), 2.15 (SD = 4.32)%) and the absolute increase in lumbar spine BMC (1.17 (SD = 2.05)g) in the Treatment group as compared with the Control group (0.00084 (SD = 0.026)g/cm(2), 0.13 (SD = 3.62)% and 0.47 (SD = 1.88)g, respectively). WBV had no significant effect for other bone quality parameters., Conclusions: WBV was effective for improving aBMD at the femoral neck of the dominant side and lumbar spine BMC in AIS subjects.

Unlabelled: IGF-I has a pivotal role in bone growth and could be one of the putative disease-modifier genes in AIS. Two SNPs in IGF-I gene promoter region were studied for any association with occurrence of AIS and for their effect on the curve severity among AIS., Methods: 506 AIS girls (Cobb>20 degrees) and 227 age-matched Chinese girls were recruited. The spine (L2-L4) and hip BMD of the subjects were measured by DXA. A subgroup of AIS patients (N=340) who were followed-up to skeletal maturity and the maximum Cobb's angle was recorded. Two SNPs were genotyped by PCR-RFLP (rs5742612 and rs2288377). The chi-square test and one-way ANOVA were used to test the association between genotypes and quantitative parameters, respectively., Results: No association was between the genotypes and the occurrence of AIS and the BMD of the spine and hip. The allelic frequency of T allele was 0.69 in AIS and control. However, the Cobb's angle was higher in patients with the homozygous T allele (Mean Cobb's angle: 38.1 degrees in TT vs 35.9 degrees in TC vs 33.2 degrees in CC group; p=0.04)., Discussion: Interestingly, IGF-I polymorphism affects the curve severity of AIS though it was not associated with onset of AIS per se. It indicates that IGF-I may be a disease modifying gene. The importance of IGF-I in skeletal growth makes it a good candidate gene which would play a role in the documented association of rapid growth with curve progression in AIS.

The aim of this study was to monitor BMD changes occurring during periods of rapid growth and to investigate whether osteopenia was a persistent phenomenon in skeletally matured AIS girls. 196 AIS Chinese girls and 122 healthy controls, aged 11-16, were follow-up for 3.5 years. Bilateral femoral neck bone mineral density (BMD) and volumetric BMD (vBMD) of the distal tibia were obtained by dual energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Osteopenia was defined if the age-adjusted BMD was below or equal to -1 standard deviation (SD). The average age at the final follow-up was 16.8 years old. The median initial Cobb angle for this group of patients was 26 degrees. The prevalence of osteopenia at the baseline measurement was 35.9%. Longitudinal BMD results demonstrated that 86.0% of osteopenic AIS girls had persistently low BMD at the time of skeletal maturity (age of 16). vBMD of distal tibia of AIS was significantly lower than that of the controls throughout the age of 13 to 17 during the period of rapid growth. In addition, there were also significant differences in vBMD among AIS (moderate and severe group) and the controls by one-way ANOVA (p<0.05). The present study for the first time revealed that over 86% of osteopenic AIS patients had persistently low BMD, at both distal tibia and femoral neck regions, at the time of skeletal maturity. Early detection and treatment of AIS-related osteopenia might help in maximizing peak bone mass during peripubertal growth that thereby minimizing risks of developing osteoporotic fractures later in life.

Generalized osteopenia and spinal deformity occur concomitantly in adolescent idiopathic scoliosis (AIS) during the peripubertal period. No large-scale study has been performed to reveal the link between scoliotic deformity and bone-mineral status in AIS. In a cross-sectional study, the extent of scoliotic-curve severity in relation to bone-mineral status was examined for 619 AIS girls and compared with those of 300 healthy non-AIS counterparts aged 11-16 years. Curve severity was categorized into a moderate (10-39 degrees) and a severe group (> or = 40 degrees) based on Cobb angle. Anthropometric parameters, bone mineral-density (BMD) and bone mineral-content (BMC) of lumbar spine, proximal femur and distal tibia were determined by dual-energy X-ray absorptiometry and peripheral QCT. Differences in anthropometric parameters and bone mass among control and the AIS-moderate and AIS-severe groups were tested by one-way ANOVA. Association between Cobb angle and bone mass was determined by univariate and multivariate analyses. Mean Cobb angle of the moderate and severe groups were 25+/-6.3 degrees and 50.2+/-11.3 degrees, respectively. Arm span and leg length among the moderate and severe AIS subjects were almost all longer than for the controls from age 13 years. Age-adjusted arm span and leg length were significantly correlated with curve severity (p < 0.015). Starting from age 13 years, most axial and peripheral BMD and BMC of the moderate or severe AIS group was significantly lower than for the controls (p < 0.029). Age-adjusted Cobb angle was inversely correlated with BMD and BMC of the distal tibia and lumbar spine among AIS subjects (p < or = 0.042). The proportion of osteopenic AIS girls in the severe group was significantly higher than that in the moderate group (p < or = 0.033). Multivariate analysis indicated that Cobb angle was inversely and independently associated with axial and peripheral BMD and BMC (p < or = 0.042). To conclude, curve severity was an inverse and independent associated factor on bone mineral mass of AIS during peripuberty. The study implied that prevention of osteopenia could be as important as controlling spinal progression in the management of AIS.