Prevalence of vitamin D insufficiency among adolescents and its correlation with bone parameters using high-resolution peripheral quantitative computed tomography.

UNLABELLED: Vitamin D deficiency and insufficiency are highly prevalent among adolescents in Hong Kong, which is a sub-tropical city with ample sunshine. Vitamin D level is significantly correlated with key bone density and bone quality parameters. Further interventional studies are warranted to define the role of vitamin D supplementation for improvement of bone health among adolescents. INTRODUCTION: The relationship between bone quality parameters and vitamin D (Vit-D) status remains undefined among adolescents. The aims of this study were to evaluate Vit-D status and its association with both bone density and bone quality parameters among adolescents. METHODS: Three hundred thirty-three girls and 230 boys (12-16 years old) with normal health were recruited in summer and winter separately from local schools. Serum 25(OH) Vit-D level, bone density and quality parameters by Dual Energy X-ray Absorptiometry (DXA) and High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT), dietary calcium intake, and physical activity level were assessed. RESULTS: Sixty-four point seven percent and 11.4 % of subjects were insufficient [25 ≤ 25(OH)Vit-D ≤ 50 nmol/L] and deficient [25(OH)Vit-D < 25 nmol/L] in Vit-D, respectively. The mean level of serum 25(OH)Vit-D in summer was significantly higher than that in winter (44.7 ± 13.6 and 35.9 ± 12.6 nmol/L, respectively) without obvious gender difference. In girls, areal bone mineral density (aBMD) and bone mineral content (BMC) of bilateral femoral necks, cortical area, cortical thickness, total volumetric bone mineral density (vBMD), and trabecular thickness were significantly correlated with 25(OH)Vit-D levels. In boys, aBMD of bilateral femoral necks, BMC of the dominant femoral neck, cortical area, cortical thickness, total vBMD, trabecular vBMD, BV/TV, and trabecular separation were significantly correlated with 25(OH)Vit-D levels. CONCLUSION: Vit-D insufficiency was highly prevalent among adolescents in Hong Kong with significant correlation between Vit-D levels and key bone density and bone quality parameters being detected in this study. Given that this is a cross-sectional study and causality relationship cannot be inferred, further interventional studies investigating the role of Vit-D supplementation on improving bone health among adolescents are warranted.

Effect of whole body vibration (WBV) therapy on bone density and bone quality in osteopenic girls with adolescent idiopathic scoliosis: a randomized, controlled trial.

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.

The effect of rigid versus flexible spinal orthosis on the gait pattern of patients with adolescent idiopathic scoliosis.

The conventional rigid spinal orthosis and the flexible spinal orthosis, SpineCor, have different treatment principles in the management of adolescent idiopathic scoliosis (AIS). These may influence the patients' gait pattern and clinical outcome. In this study, gait analysis on patients with AIS undergoing these two orthotic interventions were conducted. The patients' lower limb kinematic and kinetic data during level walking were collected using a motion analysis system and two force platforms in four test conditions: pre-intervention, having used the orthosis for 1 month and 1 year (in and out of the orthosis). Twenty-one subjects were randomly assigned to the rigid spinal orthosis group (10 subjects) and the SpineCor group (11 subjects). Neither group showed gait asymmetry when comparing the convex and concave sides in the four test conditions. However, significant reduction in the range of motion of the pelvis and hip joints in the coronal plane were found. Although patients with AIS undergoing these two orthotic interventions showed significant changes in walking pattern within the study period, their long-term effect on gait and function requires further investigation through long-term prospective studies.

Altered White Matter Microstructure in the Corpus Callosum and Its Cerebral Interhemispheric Tracts in Adolescent Idiopathic Scoliosis: Diffusion Tensor Imaging Analysis.

BACKGROUND AND PURPOSE: Neural system was one of the important contributors to the etiopathogenesis of adolescent idiopathic scoliosis; additionally, the morphology of corpus callosum interconnecting both hemispheres of the brain was found to be altered morphologically. Our aim was to evaluate and compare the microstructural changes of the corpus callosum and its interhemispheric white matter fiber tracts interconnecting both cerebral hemispheres in patients with adolescent idiopathic scoliosis and matched controls using diffusion tensor imaging. MATERIALS AND METHODS: Brain DTI was performed in 69 patients with adolescent idiopathic scoliosis (female, right thoracic/thoracolumbar curve) and 40 age-matched controls without adolescent idiopathic scoliosis (female). 2D and 3D segmentation of the corpus callosum were performed using a region-growing method, and the corpus callosum was further divided into 6 regions, including the rostrum, genu, anterior and posterior midbodies, isthmus, and splenium. The laterality index was calculated to quantify the asymmetry of the corpus callosum. Interhemispheric fiber tractography were performed using the Brodmann atlas. RESULTS: 2D ROI analysis revealed reduced fractional anisotropy in the genu and splenium (P = .075 and P = .024, respectively). Consistently reduced fractional anisotropy on the left sides of the genu and splenium was also found in 3D ROI analysis (P = .03 and P = .012, respectively). The laterality index analysis revealed a pseudo-right lateralization of the corpus callosum in adolescent idiopathic scoliosis. Interhemispheric fibers via the splenium interconnecting Brodmann 3, 1, and 2; Brodmann 17; and Brodmann 18 (corresponding to the primary somatosensory cortex and primary and secondary visual cortices) were also found to have reduced fractional anisotropy (P ≤ .05). CONCLUSIONS: Reduced fractional anisotropy was found in the genu and splenium of the corpus callosum and corresponding interhemispheric fiber tracts interconnecting the somatosensory and visual cortices via the splenium. Our results are suggestive of altered white matter microstructure within the brain of those with adolescent idiopathic scoliosis, which could be related to abnormal brain maturation during adolescence in adolescent idiopathic scoliosis and could possibly explain the previously documented somatosensory function impairment and visuo-oculomotor dysfunction in this condition.

Gonadal shield: is it the Albatross hanging around the neck of developmental dysplasia of the hip research?

PURPOSE: Prospective randomized controlled trials and long-term studies are essential future directions for building -evidence-based practices in developmental dysplasia of the hip (DDH), however, sufficient attrition in data (> 20%) can introduce bias deteriorating research quality. Pelvic radiography is synonymous with DDH assessment and so are -Gonadal Shield (GS) recommendations with pelvic radiography. -Nonetheless, losses to diagnostic information and inadequate protection have been increasingly implicated to GS usage, with significantly worse implications in female patients. Understandably for DDH, a disease with 80% female prevalence, the impact of GS usage on quality of radiographs and readability of radiological data may be drastic. This study aims to objectively define the implications of GS recommendations in DDH patients. METHODS: Pelvis radiographs of all DDH patients under the hip surveillance programme at a tertiary care hospital with a written protocol for GS usage were evaluated. Images were reviewed for gender, GS presence, adequate gonadal protection and obstruction of essential anatomical landmarks for pelvic indices. RESULTS: In all, 131 pelvis radiographs with DDH diagnoses (age: 1.25 to 6 years; 107 female, 24 male pelvises) were reviewed. Only 42.67% (56) of pelvis radiographs used GS despite the presence of a clear protocol. Useful anatomical landmarks were obstructed in 58.9% of radiographs with GS present. Lost diagnostic information was more common in female patients than male patients (68.1% versus 11.1%, p < 0.01). GS was ineffective at gonadal protection in 73.2% (41) of the pelvises with worse protection in female patients (78.7% vs 44.4%; p = 0.03). CONCLUSIONS: Ironically, essential anatomy was obstructed in all the adequately protected female pelvises. Routine GS usage results in substantial attrition of radiographic data in DDH patients. LEVEL OF EVIDENCE: III.

A comparison of the clinical effectiveness of spinal orthoses manufactured using the conventional manual method and CAD/CAM method in the management of AIS.

Spinal orthoses are commonly prescribed to patients with moderate AIS for prevention of further deterioration. In a conventional manufacturing method, plaster bandages are used to get patient's body contour and plaster cast is rectified manually. With the introduction of CAD/CAM system, a series of automated processes from body scanning to digital rectification and milling of positive model can be performed in a fast and accurate fashion. This project is to study the impact of CAD/CAM method as compared with the conventional method. In assessing the 147 recruited subjects fitted with spinal orthoses (43 subjects using conventional method and 104 subjects using CAD/CAM method), significant decreases (p<0.05) were found in the Cobb angles when comparing the pre-intervention data with that of the first year of intervention. Regarding the learning curve, Orthotists are getting more competent with the CAD/CAM technique in four years time. The mean productivity of the CAD/CAM method is 2.75 times higher than that of the conventional method. The CAD/CAM method could achieve similar clinical outcomes and with its high efficiency, could be considered as substitute for conventional methods in fabricating spinal orthoses for patients with AIS.

Genetic association study of insulin-like growth factor-I (IGF-I) gene with curve severity and osteopenia in adolescent idiopathic scoliosis.

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.

Persistent osteopenia in adolescent idiopathic scoliosis--longitudinal monitoring of bone mineral density until skeletal maturity.

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.

Changes in vertebral neural arch morphometry and functional tethering of spinal cord in adolescent idiopathic scoliosis--study with multi-planar reformat magnetic resonance imaging.

With the use of multiplanar reformat Magnetic Resonance imaging, AIS patients were found to have significantly reduced pedicle widths on concavity. Pattern of vertebral asymmetry was also exaggerated with smaller pedicle width, length and area on concavity. The cord appeared more roundish and was deviated to the concavity at apical vertebra in AIS. A tethering force might therefore be present on the cord along the transverse axis in AIS, accounted by the relatively fixed position of the exit nerve roots and deviation of the cord from the exit foraminae of the corresponding vertebra.

Osteopenia: a new prognostic factor of curve progression in adolescent idiopathic scoliosis.

BACKGROUND: Studies have shown that 27% to 38% of girls with adolescent idiopathic scoliosis have systemic osteopenia. The aim of this study was to investigate whether osteopenia could serve as one of the important prognostic factors in predicting curve progression. METHODS: A prospective study was performed in 324 adolescent girls with adolescent idiopathic scoliosis who had a mean age of thirteen and a half years. Bone mineral density of the spine and both hips was measured at the time of the clinical diagnosis of scoliosis. All patients were followed longitudinally until skeletal maturity or until the curve had progressed > or =6 degrees . The univariate chi-square test and stepwise logistic regression were used to predict the prevalence of curve progression, and a receiver operating characteristic curve was plotted. RESULTS: The overall prevalence of curve progression was 50%. The prevalence of osteopenia at the spine and hips was 27.5% and 23.1%, respectively. A larger initial Cobb angle (odds ratio = 4.6), a lower Risser grade (odds ratio = 4.7), premenarchal status (odds ratio = 2.5), osteopenia in the femoral neck of the hip on the side of the concavity (odds ratio = 2.3), and a younger age at the time of diagnosis (odds ratio = 2.1) were identified as risk factors in predicting curve progression. A predictive model was established, and the area under the receiver operating characteristic curve of the model was 0.80 (p < 0.01). CONCLUSION: Osteopenia may be an important risk factor in curve progression. The measurement of bone mineral density at the time of diagnosis may serve as an additional objective measurement in predicting curve progression in adolescent idiopathic scoliosis. The bone mineral density-inclusive predictive model may be used in treatment planning for patients with adolescent idiopathic scoliosis who are at high risk of curve progression.