Effect of Obersity on Gait Symmetry Following Anterior Cruciate Ligament Transection

Introduction: Obesity is considered a risk factor for both the onset and progression of osteoarthritis (OA). Obesity, OA and mechanical perturbation have all been identified individually to increase gait asymmetry. The purpose of this study was to assess the effect of obesity on the progression of gait asymmetry as a component of a diet induced obesity (DIO) OA model in the presence of mechanical perturbation. Methods: 28 Sprague Dawley Rats were assigned to a high fat, high sucrose diet or a low fat diet group (LFD). Twelve weeks post DIO groups receive an anterior cruciate ligament transection (ACL-X), or sham surgery. Pre-surgery, 1-week, 8-week, and 16-weeks post-surgery, kinetic data were collected by 3-D force plate analysis. Peak vertical ground reaction force (pVGRF), vertical impulse, and stance times were quantified then compared between limbs to quantify an asymmetry index (AI). Results: There were no differences in normalized pVGRF AI between hind limbs in the DIO or LFD group animals. Stance times decreased for both hind limbs in both DIO group animals. DIO ACL-X group animals had a greater AI compared to LFD group animals at 1-week post-surgery, and both DIO group animals had greater AI at 8 and 16 weeks post-surgery, compared to LFD group animals. Conclusion: DIO group animals exhibited gait patterns with increased asymmetries compared to LFD group animals, regardless of presence or absence of mechanical perturbation, suggesting that obesity causes distinct changes in gait patterns accelerating the onset and progression of knee osteoarthritis

Effect of obesity on gait symmetry following anterior cruciate ligament transection

INTRODUCTION High fat diet and the resulting obesity are associated with chronic inflammation, which is thought to exacerbate osteoarthritis (OA) [1]. Also, obesity has been suggested to increase gait asymmetry [2]. To our knowledge, no one has evaluated the added effect of obesity in an instability OA progression model such as anterior cruciate ligament transection (ACL-X). The purpose of this study is to assess the effect of obesity on the progression of gait asymmetry, when factors are normalized for body weight, following an ACL-X protocol. We hypothesize that High-fat diet ACL-X animals will experience greater asymmetry than low-fat ACL-X animals over time. METHODS Twenty-eight male Sprague-Dawley rats were randomly assigned to either a high fat diet (HFD) or a low fat diet (LFD) group. The HFD group (n=18) received high fat sucrose food (40% fat, Diet #102412, Dyets, Inc) and the LFD group (n=10) received lean chow (13.5% fat, LabDiet 5001). Twelve weeks post diet induction, baseline 2-D kinematics and 3-D kinetic measurements were collected on a runway with two embedded side-by-side 7.5 x 30 cm force plates (Bertec, Columbus, OH). A minimum of two successful kinematic and kinetic trials for each limb were included in this analysis. Then, all animals were randomly assigned to receive an ACL-X (HFD n=12, LFD n=5) or surgical sham (HFD n=6, LFD n=4). Kinematic and kinetic data were collected 1-week post surgery, and again at 8 weeks post surgery. An Asymmetry Index (AI) was used to compare differences between limbs. The AI was calculated by: (Contralateral (BW) – Experimental (BW)) X 100% Contralateral (BW) All data sets were compared for AI changes due to diet, surgery, diet*surgery, and over time using non-parametric statistics. RESULTSTwenty animals successfully met the inclusion criteria and were analyzed. In Figure 1, the normalized AI vertical impulse result for all groups is shown. The LFD ACL-X group (n=5) normalized AI vertical impulse was 12% (±15%), 20% (±6.4%), and 17% (±5.7%) respectively. The HFD SHAM group normalized AI vertical impulse was 16% (±17.2%), 34% (±7.2%), and 44% (±13%) respectively. The HFD ACL-X normalized AI vertical impulse was 17% (±13%), 37% (±5.4%) and 44% (±1%) respectively. Figure 1. Normalized AI vertical impulse is demonstrated over time for three time points: Pre-Surgery, 1-week post surgery and 8-week post-surgery. * Indicates p<0.05.DISCUSSION AND CONCLUSIONS AI impulse was increased in all groups 1-week post surgery, but the HFD ACL-X had an increased AI when compared with LFD ACL-X (p<0.05). Both HFD groups had a greater normalized AI vertical impulse when compared with the LFD ACL-X group 8-weeks post surgery (p<0.05). The rats were first introduced to the runway and force plate at baseline testing, which contributes to the large variability seen pre-surgery. In conclusion, gait asymmetry is exacerbated over time for normalized AI vertical impulse after ACL-X in HFD animals. Conversely, a trend was evident towards recovery, or decreased AI in the LFD animals. A fourth data set, 16 weeks post surgery, will be analyzed to further characterize the effect of diet and surgery on this measure in ACL-X animals over time.

The revised Approved Instructional Resources score:An improved quality evaluation tool for online educational resources

BACKGROUND: Free Open-Access Medical education (FOAM) use among residents continues to rise. However, it often lacks quality assurance processes and residents receive little guidance on quality assessment. The Academic Life in Emergency Medicine Approved Instructional Resources tool (AAT) was created for FOAM appraisal by and for expert educators and has demonstrated validity in this context. It has yet to be evaluated in other populations.OBJECTIVES: We assessed the AAT's usability in a diverse population of practicing emergency medicine (EM) physicians, residents, and medical students; solicited feedback; and developed a revised tool.METHODS: As part of the Medical Education Translational Resources: Impact and Quality (METRIQ) study, we recruited medical students, EM residents, and EM attendings to evaluate five FOAM posts with the AAT and provide quantitative and qualitative feedback via an online survey. Two independent analysts performed a qualitative thematic analysis with discrepancies resolved through discussion and negotiated consensus. This analysis informed development of an initial revised AAT, which was then further refined after pilot testing among the author group. The final tool was reassessed for reliability.RESULTS: Of 330 recruited international participants, 309 completed all ratings. The Best Evidence in Emergency Medicine (BEEM) score was the component most frequently reported as difficult to use. Several themes emerged from the qualitative analysis: for ease of use-understandable, logically structured, concise, and aligned with educational value. Limitations include deviation from questionnaire best practices, validity concerns, and challenges assessing evidence-based medicine. Themes supporting its use include evaluative utility and usability. The author group pilot tested the initial revised AAT, revealing a total score average measure intraclass correlation coefficient (ICC) of moderate reliability (ICC = 0.68, 95% confidence interval [CI] = 0 to 0.962). The final AAT's average measure ICC was 0.88 (95% CI = 0.77 to 0.95).CONCLUSIONS: We developed the final revised AAT from usability feedback. The new score has significantly increased usability, but will need to be reassessed for reliability in a broad population.</p

The Social Media Index as an Indicator of Quality for Emergency Medicine Blogs: A METRIQ Study

Study objective: Online educational resources such as blogs are increasingly used for education by emergency medicine clinicians. The Social Media Index was developed to quantify their relative impact. The Medical Education Translational Resources: Indicators of Quality (METRIQ) study was conducted in part to determine the association between the Social Media Index score and quality as measured by gestalt and previously derived quality instruments. Methods: Ten blogs were randomly selected from a list of emergency medicine and critical care Web sites. The 2 most recent clinically oriented blog posts published on these blogs were evaluated with gestalt, the Academic Life in Emergency Medicine Approved Instructional Resources (ALiEM AIR) score, and the METRIQ-8 score. Volunteer raters (including medical students, emergency medicine residents, and emergency medicine attending physicians) were identified with a multimodal recruitment methodology. The Social Media Index was calculated in February 2016, November 2016, April 2017, and December 2017. Pearson's correlations were calculated between the Social Media Index and the average rater gestalt, ALiEM AIR score, and METRIQ-8 score. Results: A total of 309 of 330 raters completed all ratings (93.6%). The Social Media Index correlated moderately to strongly with the mean rater gestalt ratings (range 0.69 to 0.76) and moderately with the mean rater ALiEM AIR score (range 0.55 to 0.61) and METRIQ-8 score (range 0.53 to 0.57) during the month of the blog post's selection and for 2 years after. Conclusion: The Social Media Index's correlation with multiple quality evaluation instruments over time supports the hypothesis that it is associated with overall Web site quality. It can play a role in guiding individuals to high-quality resources that can be reviewed with critical appraisal techniques