Association of Chronic Pain With Participation in Motor Skill Activities in Children With Cerebral Palsy

Many children with cerebral palsy (CP) experience the secondary condition of pain, which is problematic because children with CP face barriers to participation in motor skill activities.1,2 Motor performance in activities of daily living among children with CP is markedly lower than that among their age-matched peers.3 Because of the potential effect of pain on children with CP, we sought to examine the association between pain and activities requiring motor skill performance (ie, difficulty dressing or bathing and participation in sport) among a nationally representative sample of US children with CP

Muscle volume is related to trabecular and cortical bone architecture in typically developing children

Introduction: Muscle is strongly related to cortical bone architecture in children; however, the relationship between muscle volume and trabecular bone architecture is poorly studied. The aim of this study was to determine if muscle volume is related to trabecular bone architecture in children and if the relationship is different than the relationship between muscle volume and cortical bone architecture. Materials and methods: Forty typically developing children (20 boys and 20 girls; 6 to 12. y) were included in the study. Measures of trabecular bone architecture [i.e., apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp)] in the distal femur, cortical bone architecture [cortical volume, total volume, section modulus (Z) and polar moment of inertia (J)] in the midfemur, muscle volume in the midthigh and femur length were assessed using magnetic resonance imaging. Total physical activity and moderate-to-vigorous physical activity were assessed using an accelerometer-based activity monitor worn around the waist for four days. Calcium intake was assessed using diet records. Relationships among the measures were tested using multiple linear regression analysis. Results: Muscle volume was moderately-to-strongly related to measures of trabecular bone architecture [appBV/TV (r=0.81), appTb.N (r=0.53), appTb.Th (r=0.67), appTb.Sp (r=-0.71); all p0.05). Because muscle volume and femur length were strongly related (r=0.91, p2.77). When muscle volume/femur length2.77 was included in a regression model with femur length, sex, physical activity and calcium intake, muscle volume/femur length2.77 was a significant predictor of appBV/TV, appTb.Th and appTb.Sp (partial r=0.44 to 0.49, p<0.05) and all measures of cortical bone architecture (partial r=0.47 to 0.54; p<0.01). Conclusions: The findings suggest that muscle volume in the midthigh is related to trabecular bone architecture in the distal femur of typically developing children. The relationship is weaker than the relationship between muscle volume in the midthigh and cortical bone architecture in the midfemur, but the discrepancy is driven, in large part, by the greater dependence of cortical bone architecture measures on femur length

Test–Retest Reliability and Correlates of Vertebral Bone Marrow Lipid Composition by Lipidomics Among Children With Varying Degrees of Bone Fragility

The reliability of lipidomics, an approach to identify the presence and interactions of lipids, to analyze the bone marrow lipid composition among pediatric populations with bone fragility is unknown. The objective of this study was to assess the test–retest reliability, standard error of measurement (SEM), and the minimal detectable change (MDC) of vertebral bone marrow lipid composition determined by targeted lipidomics among children with varying degrees of bone fragility undergoing routine orthopedic surgery. Children aged 10 to 19 years, with a confirmed diagnosis of adolescent idiopathic scoliosis (n = 13) or neuromuscular scoliosis and cerebral palsy (n = 3), undergoing posterior spinal fusion surgery at our institution were included in this study. Transpedicular vertebral body bone marrow samples were taken from thoracic vertebrae (T11, 12) or lumbar vertebrae (L1 to L4). Lipid composition was assessed via targeted lipidomics and all samples were analyzed in the same batch. Lipid composition measures were examined as the saturated, monounsaturated, and polyunsaturated index and as individual fatty acids. Relative and absolute test–retest reliability was assessed using the intraclass correlation coefficient (ICC), SEM, and MDC. Associations between demographics and index measures were explored. The ICC, SEM, and MDC were 0.81 (95% CI, 0.55–0.93), 1.6%, and 4.3%, respectively, for the saturated index, 0.66 (95% CI, 0.25–0.87), 3.5%, and 9.7%, respectively, for the monounsaturated index, and 0.60 (95% CI, 0.17–0.84), 3.6%, and 9.9%, respectively, for the polyunsaturated index. For the individual fatty acids, the ICC showed a considerable range from 0.04 (22:2n‐6) to 0.97 (18:3n‐3). Age was positively correlated with the saturated index (r2 = 0.36; p = 0.014) and negatively correlated with the polyunsaturated index (r2 = 0.26; p = 0.043); there was no difference in index measures by sex (p > 0.58). The test–retest reliability was moderate‐to‐good for index measures and poor to excellent for individual fatty acids; this information can be used to power research studies and identify measures for clinical or research monitoring. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163414/2/jbm410400_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163414/1/jbm410400.pd

The persistence of epiphyseal scars in the distal radius in adult individuals

The use of radiographic imaging in the estimation of chronological age facilitates the analysis of structures not visible on gross morphological inspection. Following the completion of epiphyseal fusion, a thin radio-opaque band, the epiphyseal scar, may be observed at the locus of the former growth plate. The obliteration of this feature has previously been interpreted as the final stage of skeletal maturation and consequently has been included as a criterion in several methods of age estimation, particularly from the distal radius. Due to the recommendations relating to age estimation in living individuals, accurate assessment of age from the distal radius is of great importance in human identification; however, the validity of the interpretation of the obliteration of the epiphyseal scar as an age-related process has not been tested. A study was undertaken to assess the persistence of epiphyseal scars in adults between 20 and 50 years of age through the assessment of 616 radiographs of left and right distal radii from a cross-sectional population. This study found that 86 % of females and 78 % of males retained some remnant of the epiphyseal scar in the distal radius. The relationships between chronological age, biological sex and the persistence of the epiphyseal scar were not statistically significant. The findings of this study indicate that the epiphyseal scars may persist in adult individuals until at least 50 years of age. No maximum age should therefore be applied to the persistence of an epiphyseal scar in the distal radius

Measuring tibial hemodynamics and metabolism at rest and after exercise using near-infrared spectroscopy

The bone vascular system is important; yet, evaluation of bone hemodynamics is difficult and expensive. This study evaluated the utility and reliability of near-infrared spectroscopy (NIRS), a portable and relatively inexpensive device, in measuring tibial hemodynamics and metabolic rate. Eleven participants were tested twice using post-occlusive reactive hyperemia technique with the NIRS probes placed on the tibia and the medial gastrocnemius (MG) muscle. Measurements were made at rest and after two levels of plantarflexion exercise. The difference between oxygenated and deoxygenated hemoglobin signal (HbDiff) could be reliably measured with small coefficients of variation (CV; range 5.7 – 9.8%) and high intraclass correlation coefficients (ICC; range 0.73 – 0.91). Deoxygenated hemoglobin rate of change, a potential marker for bone metabolism, also showed good reliability (CV range 7.5 – 9.8%, ICC range 0.90 – 0.93). The tibia was characterized with a much slower metabolic rate compared to MG (pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Fat‐free soft tissue deficit in children with CP is more pronounced in the appendicular than in the non‐appendicular regions

Background and Objective(s) Cerebral palsy (CP) is a neurological disorder characterized by skeletal muscle deficit. However, whether there is a regional‐specific skeletal muscle deficit in children with CP is unknown. The purpose of this study was to determine whether fat‐free soft tissue mass (FFST) ‐ a commonly used surrogate for skeletal muscle mass ‐ is more compromised at the appendages than at the trunk in children with CP, and whether we can use physical characteristics data to accurately estimate appendicular FFST and its derived indexes that account for height differences. Study Design Cross‐sectional. Study Participants and Settings Forty two children with CP (4–13y) were recruited from local pediatric hospitals. Forty‐two typically developing children matched to children with CP for sex, age and race were also recruited via word of mouth and flyers. Materials and Methods Whole body FFST (FFSTwhole), appendicular FFST and non‐appendicular FFST were estimated from a dual‐energy X‐ray absorptiometry whole body scan. Appendicular FFST index 1 (appendicular FFSTI1) and 2 (appendicular FFSTI2) were estimated by dividing appendicular FFST by height and height squared, respectively. Statistical models were developed to estimate appendicular FFST, appendicular FFSTI1 and appendicular FFSTI2 in both groups. Results When compared to typically developing children, children with CP had 21% lower FFSTwhole, 30% lower appendicular FFST, 14% lower non‐appendicular FFST, 23% lower appendicular FFSTI1, 19% lower appendicular FFSTI2 and 9% lower appendicular FFST/FFSTwhole (all ppr=0.95, 0.92 and 0.80, respectively; all pp\u3e0.99). However, when the difference in estimated values and measured values of appendicular FFST, FFSTI1 and FFSTI2 were plotted against measured values, there was an inverse relationship (r=−0.382, −0.479 and −0.603, respectively, all p Conclusions or Significance Children with CP have a remarkable deficit in FFST that is more pronounced in appendicular than the non‐appendicular regions. Preliminary models developed using data from children with CP can provide reasonable estimates of appendicular FFST and indexes, but further development of the models is needed. Link to Work:https://doi.org/10.1111/dmcn.1435

Sex differences in trabecular bone microarchitecture are not detected in pre and early pubertal children using magnetic resonance imaging

Sex differences in trabecular bone microarchitecture have been reported in adults and adolescents, but studies in children are lacking. The primary aim of this study was to determine if there are sex differences in magnetic resonance imaging (MRI)-based measures of trabecular bone microarchitecture at the distal femur of children. Pre and early pubertal boys (n = 23) and girls (n = 20) between the 5th and 95th percentiles for height, body mass and BMI were studied. Apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th), trabecular separation (appTb.Sp) and a composite measure of trabecular bone microarchitecture (TBMcom) were assessed at the lateral aspect of the distal femur using MRI. Areal bone mineral density (aBMD), bone mineral content (BMC) and bone area were assessed at the distal femur using dual-energy X-ray absorptiometry (DXA). Tanner staging was used to assess pubertal development. Physical activity was assessed using an accelerometry-based activity monitor. Calcium intake was assessed using diet records. There were no sex differences in age, height, femur length, body mass, physical activity or calcium intake (all P > 0.05). There were no sex differences in any MRI-based measure of trabecular bone microarchitecture. Consistent with the MRI-based measures, there were no differences in aBMD, BMC or bone area from DXA at the distal femur (P > 0.05). appBV/TV, appTb.N, appTb.Th, appTb.Sp and TBMcom were also moderately to strongly related to aBMD (r = 0.73, 0.63, 0.51, − 0.74 and 0.61, respectively, p < 0.001) and BMC (r = 0.84, 0.63, 0.66, − 0.80 and 0.77, respectively, P < 0.001). The findings suggest that there are no differences in measures of trabecular bone microarchitecture at the distal femur of pre and early pubertal boys and girls who are similar in size, physical activity and calcium intake. Future studies with larger sample sizes that cover all pubertal stages are needed to determine if sex differences in trabecular bone microarchitecture emerge at the distal femur and other weight bearing bone sites