Functional Elbow Range of Motion in Children and Adolescents.

BACKGROUND: The functional elbow range of motion in children and adolescents has not been previously reported. In adults, a functional motion arc of 30 to 130 degrees of elbow flexion and 50 degrees of pronation to 50 degrees of supination is well established. Contemporary tasks such as cellular phone use and keyboarding require greater elbow flexion and pronation than the functional motion arc. Whether or not this is true in children has yet to be established. We hypothesize that to perform functional and contemporary tasks, children and adolescents use a greater range of elbow motion and forearm rotation as compared with adults. METHODS: Twenty-eight subjects performed 8 functional tasks and 4 contemporary tasks. Kinematic data were captured using a 3-dimensional motion analysis system as previously described. Mean and SD was collected for elbow flexion, extension, pronation, and supination. Unpaired t tests were performed to compare elbow kinematics of children 6- to 11-year-old (n=14) to that of adolescents 12- to 17-year-old (n=14), with a significance criterion of P-value <0.05. RESULTS: The mean arc of motion to achieve functional tasks was 28 to 146 degrees of elbow extension/flexion and 54 degrees of supination to 65 degrees of pronation. Contemporary tasks utilized 40 to 148 degrees of elbow extension/flexion and 49 degrees of supination to 65 degrees of pronation. A greater supination/pronation arc (107 degrees) and greater elbow flexion (148 degrees) were used to bring a cellular phone to the ear, whereas greater pronation (65 degrees) was used to type on a keyboard. Statistically significant differences were observed between children and adolescents in each of the 12 tasks, with the exception of using a fork. CONCLUSIONS: A motion arc of 30 to 130 degrees of elbow flexion and 50 to 50 degrees of pronation/supination is sufficient to achieve most positional and functional tasks in children and adolescents. However, specific contemporary tasks such as the use of a cellular phone and typing on a keyboard utilize more elbow flexion and pronation. Awareness of greater use of flexion and pronation to achieve contemporary tasks may help guide surgeons in the care of patients with posttraumatic elbow and forearm deformities and contractures. LEVEL OF EVIDENCE: Level II-investigation of a diagnostic test.

Embryonic progenitor pools generate diversity in fine-scale excitatory cortical subnetworks.

The mammalian neocortex is characterized by a variety of neuronal cell types and precise arrangements of synaptic connections, but the processes that generate this diversity are poorly understood. Here we examine how a pool of embryonic progenitor cells consisting of apical intermediate progenitors (aIPs) contribute to diversity within the upper layers of mouse cortex. In utero labeling combined with single-cell RNA-sequencing reveals that aIPs can generate transcriptionally defined glutamatergic cell types, when compared to neighboring neurons born from other embryonic progenitor pools. Whilst sharing layer-associated morphological and functional properties, simultaneous patch clamp recordings and optogenetic studies reveal that aIP-derived neurons exhibit systematic biases in both their intralaminar monosynaptic connectivity and the post-synaptic partners that they target within deeper layers of cortex. Multiple cortical progenitor pools therefore represent an important factor in establishing diversity amongst local and long-range fine-scale glutamatergic connectivity, which generates subnetworks for routing excitatory synaptic information.

A systematic review of spinal research conducted using the National Surgical Quality Improvement Program.

BACKGROUND CONTEXT: Over the course of the last decade, interest in the use of large data repositories for clinical research in orthopedic and spine surgery has grown substantially. Detractors maintain that the clinical relevance of research conducted using large registries is limited, and that the academic influence of such studies is minimal. Such contentions have not been empirically evaluated. PURPOSE: This study sought to perform a systematic review of spinal research conducted using the National Surgical Quality Improvement Program (NSQIP). STUDY DESIGN: This is a systematic review. OUTCOME MEASURES: Impact factor (IF) of the journal of publication and number of citations of published articles conducted using the NSQIP. METHODS: Orthopedic and spine-specific NSQIP articles published from January 1, 2007 to July 31, 2015, were identified through a query of PubMed or Medline, Embase, Web of Science, and Scopus. Articles were classified by journal of publication, year of publication, study topic, study purpose, and method of statistical analysis. Spine surgical publications were compared with other orthopedic research conducted using the NSQIP. The primary dependent variables for the purposes of statistical testing were IF of the journal in which the article was published and the number of citations for each publication. Negative binomial regression was used to evaluate the characteristics of papers associated with increased IF and number of citations. RESULTS: Of the 1,525 articles identified in the initial search, 114 studies were considered eligible for inclusion in the systematic review. The average IF for the journals publishing orthopedic NSQIP articles was 2.75 (standard deviation [SD] 1.22, range 0-5.28), whereas it was 2.52 (SD 0.81, range 1.38-5.28) for spinal research. The average number of citations per article was 6.08 (SD 10.9, range 0-69) and 6.4 (SD 12.0, range 0-69) for spine-specific studies. Following negative binomial regression, only IF (regression coefficients [RC] 0.31; 95% confidence intervals [CI] 0.08, 0.55) and the year of publication (RC -1.29; 9% CI -1.64, -0.95) were found to have a statistically significant association with number of citations. Among spine-specific research articles, only the year of publication was found to influence the number of citations (RC -1.29; 95% CI -1.94, -0.64). CONCLUSIONS: Our findings indicate that the academic impact of orthopedic and spine surgical research conducted using NSQIP is highly variable, with most publications found to have relatively low impact. As our evaluation of study characteristics associated with high-impact publications and increased citations were unable to uncover factors that are likely translatable, we suggest following research design guidelines that highlight best practices when using large datasets for orthopedic research.

Acute Response of the Hippocampal Transcriptome Following Mild Traumatic Brain Injury After Controlled Cortical Impact in the Rat.

We have previously demonstrated that mild controlled cortical impact (mCCI) injury to rat cortex causes indirect, concussive injury to underlying hippocampus and other brain regions, providing a reproducible model for mild traumatic brain injury (mTBI) and its neurochemical, synaptic, and behavioral sequelae. Here, we extend a preliminary gene expression study of the hippocampus-specific events occurring after mCCI and identify 193 transcripts significantly upregulated, and 21 transcripts significantly downregulated, 24 h after mCCI. Fifty-three percent of genes altered by mCCI within 24 h of injury are predicted to be expressed only in the non-neuronal/glial cellular compartment, with only 13% predicted to be expressed only in neurons. The set of upregulated genes following mCCI was interrogated using Ingenuity Pathway Analysis (IPA) augmented with manual curation of the literature (190 transcripts accepted for analysis), revealing a core group of 15 first messengers, mostly inflammatory cytokines, predicted to account for >99% of the transcript upregulation occurring 24 h after mCCI. Convergent analysis of predicted transcription factors (TFs) regulating the mCCI target genes, carried out in IPA relative to the entire Affymetrix-curated transcriptome, revealed a high concordance with TFs regulated by the cohort of 15 cytokines/cytokine-like messengers independently accounting for upregulation of the mCCI transcript cohort. TFs predicted to regulate transcription of the 193-gene mCCI cohort also displayed a high degree of overlap with TFs predicted to regulate glia-, rather than neuron-specific genes in cortical tissue. We conclude that mCCI predominantly affects transcription of non-neuronal genes within the first 24 h after insult. This finding suggests that early non-neuronal events trigger later permanent neuronal changes after mTBI, and that early intervention after mTBI could potentially affect the neurochemical cascade leading to later reported synaptic and behavioral dysfunction.