Psychological Factors Are Related to Neuromuscular Asymmetries After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: After an anterior cruciate ligament reconstruction (ACLR), only 47% of military members return to full duty, possibly due to persistent neuromuscular asymmetries. Psychological factors may also contribute to reduced return to duty in military members. HYPOTHESIS: Psychological factors and time since surgery would be associated negatively with neuromuscular asymmetries, asymmetries would be greater in cadets postsurgery when compared with healthy controls, and asymmetries would be greater at earlier timepoints after ACLR. STUDY DESIGN: Case control. LEVEL OF EVIDENCE: Level 4. METHODS: This study examined the relationship between psychological factors and time since surgery with neuromuscular asymmetry, compared neuromuscular asymmetries between cadets with and without a history of ACLR, and explored differences in neuromuscular asymmetries at different timepoints in cadets with a history of ACLR. A total of 37 cadets post-ACLR (18.3 ± 9 months) and 28 controls participated. Psychological factors were assessed using the Tampa Scale of Kinesiophobia and Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI). Participants performed a drop-jump landing, joint positioning sense (JPS), and isometric quadriceps strength testing. Peak vertical ground-reaction forces (vGRF), absolute angle of replication, peak quadriceps torque, rate of torque development (RTD), and RTD time torque interval 200 ms (TTI200) were analyzed. RESULTS: The ACL-RSI score was significantly related to limb symmetry index (LSI) peak quadriceps torque (r = 0.617, P < 0.01), LSI RTD (r = 0.367, P = 0.05), and LSI TTI200 (r = 0.0489, P < 0.01), but not time since surgery, JPS, or LSI peak vGRF. Cadets with a history of ACLR had significantly lesser ACL-RSI scores and greater asymmetries compared with controls. CONCLUSION: Reduced psychological readiness was associated with increased neuromuscular asymmetries after ACLR. CLINICAL RELEVANCE: Clinicians should assess psychological readiness during rehabilitation after ACLR.

Comprehensive genomic analysis reveals molecular heterogeneity in pediatric ALK-positive anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) is a mature T-cell lymphoma that accounts for for 10-15% of childhood lymphomas. Despite the observation that more than 90% of pediatric cases harbor the anaplastic lymphoma kinase (ALK) rearrangement resulting in aberrant ALK kinase expression, there is significant clinical, morphologic, and biological heterogeneity. To gain insights into the genomic aberrations and molecular heterogeneity within ALK-positive ALCL(ALK+ ALCL), we analyzed 46 pediatric ALK+ ALCLs by whole-exome sequencing, RNA-sequencing, and DNA methylation profiling. Whole-exome sequencing found on average 25 SNV/Indel events per sample with recurring genetic events in regulators of DNA damage (TP53, MDM4), transcription (JUNB), and epigenetic regulators (TET1, KMT2B, KMT2A, KMT2C, KMT2E). Gene expression and methylation profiling consistently subclassified ALK+ ALCLs into two groups characterized by diferential ALK expression levels. The ALK-low group showed enrichment of pathways associated with immune response, cytokine signaling, and a hypermethylated predominant pattern compared to the ALK- high group, which had more frequent copy number changes, and was enriched with pathways associated with cell growth, proliferation, metabolic pathways, and. Taken together, these findings suggest that there is molecular heterogeneity within pediatric ALK+ALCL, predicting distinct biological mechanisms that may provide novel insights into disease pathogenesis and represent prognostic markers.

Modified fructan accumulation through overexpression of wheat fructan biosynthesis pathway fusion genes Ta1SST:Ta6SFT.

BACKGROUND: Fructans are water-soluble carbohydrates that accumulate in wheat and are thought to contribute to a pool of stored carbon reserves used in grain filling and tolerance to abiotic stress. RESULTS: In this study, transgenic wheat plants were engineered to overexpress a fusion of two fructan biosynthesis pathway genes, wheat sucrose: sucrose 1-fructosyltransferase (Ta1SST) and wheat sucrose: fructan 6-fructosyltransferase (Ta6SFT), regulated by a wheat ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (TaRbcS) gene promoter. We have shown that T4 generation transgene-homozygous single-copy events accumulated more fructan polymers in leaf, stem and grain when compared in the same tissues from transgene null lines. Under water-deficit (WD) conditions, transgenic wheat plants showed an increased accumulation of fructan polymers with a high degree of polymerisation (DP) when compared to non-transgenic plants. In wheat grain of a transgenic event, increased deposition of particular fructan polymers such as, DP4 was observed. CONCLUSIONS: This study demonstrated that the tissue-regulated expression of a gene fusion between Ta1SST and Ta6SFT resulted in modified fructan accumulation in transgenic wheat plants and was influenced by water-deficit stress conditions.

Electrographic screening for infantile epileptic spasms syndrome in a single sleep-wake cycle.

OBJECTIVE: Infantile epileptic spasms syndrome (IESS) is a common and urgent diagnosis with seizure and nonseizure mimics. Evaluation with prolonged video-electroencephalography (EEG) can be time-consuming and costly. This study investigated the use of EEG review of a single sleep-wake cycle to exclude IESS. METHODS: We retrospectively reviewed video-EEG studies to rule out IESS in children between the ages of 2 months and 2 years in the period from January 2019 through June 2020. EEG studies were reviewed from the start of the recording through the first sleep-wake cycle and scored as "normal," "consistent with IESS," or "abnormal but not diagnostic of IESS." Scores were compared to the clinical report created by analysis of the entire video-EEG. RESULTS: Inclusion criteria were met in 238 EEG studies. The mean patient age was 7.6 months. The median duration of the full study was 908 min, compared to 107.5 min for the first sleep-wake cycle only. The median difference in recording time was 801 min, p-value < .01. Scored outcomes were similar. Sixty-eight percent of EEG studies were scored as "normal" on first sleep-wake cycle review as compared to 63% on full study review, 13% scored as "consistent with IESS" compared to 16% and 19% scored as "abnormal but not diagnostic of IESS" compared to 21%. Sensitivity and specificity of the first sleep-wake cycle review for studies "consistent with IESS" was 84% and 100%, respectively. No cases of IESS were scored as normal on first sleep-wake cycle review. SIGNIFICANCE: A single sleep-wake cycle captured on EEG can triage studies when IESS is suspected. A normal first sleep-wake cycle did not miss cases of IESS and could result in reduced EEG recording time. Because most of these cases presented to an emergency department, a normal first sleep-wake cycle may help providers determine the acuity, or necessity, of further testing.

Pembrolizumab-Induced Nodular Posterior Scleritis.

Purpose: To report a case of painless posterior scleritis presenting as a choroidal nodule in a patient with history of a tumor being treated with pembrolizumab. Methods: A case and its findings were analyzed, and a relevant literature review was performed. Results: A 20-year-old woman with a history of ependymoma presented with painless blurred vision in the right eye after being started on pembrolizumab for a tumor recurrence. Fundoscopy showed a solitary amelanotic choroidal lesion with surrounding subretinal fluid in the affected eye. Ultrasonography showed moderate internal reflectivity and fluid in Tenon capsule consistent with nodular posterior scleritis. After a course of systemic steroids and discontinuation of the pembrolizumab, the choroidal lesion completely resolved. Conclusions: Clinicians should be aware of posterior scleritis as an ocular complication of this class of medications.

Understanding the Mechanism for Adsorption of Pb(II) Ions by Cu-BTC Metal-Organic Frameworks.

With the growing population, industrialization, and agriculture, water contamination not only affects people but entire ecosystems. Metal-organic frameworks (MOFs), because of their large surface area and porosity, show great potential as adsorbents for removing pollutants, such as heavy metals, from contaminated water. The current research aims at examining copper (II) benzene-1,3,5-tricarboxylate (Cu-BTC) MOFs and understanding the mechanism for their adsorption of Pb(II) from aqueous solution. The Cu-BTC samples were characterized using FTIR and XRD, and their surface area and porosity were determined based on N2 adsorption isotherms. The concentration of Pb(II) in the solutions was measured using atomic absorption spectroscopy (AAS). Both kinetic and equilibrium adsorption data were collected and then analyzed using numerical models. The analyses led to the findings that the limiting steps in the adsorption of Pb(II) on Cu-BTC are (a) pore diffusion of Pb(II) and (b) the availability of the active sites on Cu-BTC MOFs. It was further revealed that the former step is more dominant in the adsorption of Pb(II) when the lead concentration is low. The latter step, which is directly proportional to the surface areas of the MOFs, affects the adsorption to a greater extent when the lead concentration is high. The results also show that adsorption of Pb(II) ions on Cu-BTC is mainly a multi-layer heterogeneous process.

Posttransplant MRD and T-cell chimerism status predict outcomes in patients who received allografts for AML/MDS.

Allogeneic stem-cell transplant allows for the delivery of curative graft-versus-leukemia (GVL) in patients with acute myeloid leukemia/myelodysplasia (AML/MDS). Surveillance of T-cell chimerism, measurable residual disease (MRD) and blast HLA-DR expression may inform whether GVL effectiveness is reduced. We report here the prognostic impact of these biomarkers in patients allografted for AML/MDS. One hundred eighty-seven patients from FIGARO, a randomized trial of reduced-intensity conditioning regimens in AML/MDS, were alive and relapse-free at the first MRD time-point and provided monitoring samples for flow cytometric MRD and T-cell chimerism, requested to month+12. Twenty-nine (15.5%) patients had at least 1 MRD-positive result posttransplant. MRD-positivity was associated with reduced overall survival (OS) (hazard ratio [HR], 2.18; P = .0028) as a time-varying Cox variable and remained significant irrespective of pretransplant MRD status in multivariate analyses (P < .001). Ninety-four patients had sequential MRD with T-cell chimerism results at months+3/+6. Patients with full donor T-cell chimerism (FDTC) had an improved OS as compared with patients with mixed donor T-cell chimerism (MDTC) (adjusted HR=0.4; P = .0019). In patients with MDTC (month+3 or +6), MRD-positivity was associated with a decreased 2-year OS (34.3%) vs MRD-negativity (71.4%) (P = .001). In contrast, in the group with FDTC, MRD was infrequent and did not affect the outcome. Among patients with posttransplant MRD-positivity, decreased HLA-DR expression on blasts significantly reduced OS, supporting this as a mechanism for GVL escape. In conclusion, posttransplant MRD is an important predictor of the outcome in patients allografted for AML/MDS and is most informative when combined with T-cell chimerism results, underlining the importance of a GVL effect in AML/MDS.

Diagnostic Imaging for Distal Extremity Injuries in Direct Access Physical Therapy: An Observational Study.

Background: Military physical therapists practicing direct-access routinely utilize diagnostic imaging and numerous published case reports demonstrate the ability of physical therapists to diagnose and appropriately disposition patients with foot/ankle and wrist/hand fractures. However, no larger cohort studies have explored the utilization of diagnostic imaging by physical therapists to detect fractures. Hypothesis/Purpose: To describe the utilization of diagnostic imaging in foot/ankle and wrist/hand injuries by physical therapists in a direct-access sports physical therapy clinic. Study Design: Retrospective cohort study. Methods: The Agfa Impax Client 6 image viewing software (IMPAX) was searched from 2014 to 2018 for patients with diagnostic imaging ordered for foot/ankle and wrist/hand injuries. The Armed Forces Health Longitudinal Technology Application (AHLTA) electronic medical record was independently reviewed by the principal and co-investigator physical therapists. Data extracted were demographics and elements from the patient history and physical examination. Results: In foot/ankle injuries, physical therapists diagnosed a fracture in 16% of the 177 cases and waited for an average of 3.9 days and 1.3 visits before ordering imaging. In wrist/hand injuries, physical therapists diagnosed a fracture in 24% of the 178 cases and waited for an average of 3.7 days and 1.2 visits before ordering imaging. The time to definitive care from the initial physical therapy evaluation was significantly different (p = 0.04) for foot/ankle fractures (0.6 days) compared to wrist/hand fractures (5.0 days). The Ottawa Ankle Rules demonstrated a negative likelihood ratio (-LR) of 0.11 (0.02, 0.72) and a positive likelihood ratio (+LR) of 1.99 (1.62, 2.44) for the diagnosis of foot/ankle fracture. Conclusions: Physical therapists utilizing diagnostic imaging in a direct-access sports physical therapy clinic diagnosed fractures in similar proportions for foot/ankle and wrist/hand injuries and quickly dispositioned patients to definitive care for those fractures. The diagnostic accuracy of the Ottawa Ankle Rules was similar to previously reported values. Level of Evidence: Level 3.

Accessory ESCRT-III proteins are conserved and selective regulators of Rab11a-exosome formation.

Exosomes are secreted nanovesicles with potent signalling activity that are initially formed as intraluminal vesicles (ILVs) in late Rab7-positive multivesicular endosomes, and also in recycling Rab11a-positive endosomes, particularly under some forms of nutrient stress. The core proteins of the Endosomal Sorting Complex Required for Transport (ESCRT) participate in exosome biogenesis and ILV-mediated destruction of ubiquitinylated cargos. Accessory ESCRT-III components have reported roles in ESCRT-III-mediated vesicle scission, but their precise functions are poorly defined. They frequently only appear essential under stress. Comparative proteomics analysis of human small extracellular vesicles revealed that accessory ESCRT-III proteins, CHMP1A, CHMP1B, CHMP5 and IST1, are increased in Rab11a-enriched exosome preparations. We show that these proteins are required to form ILVs in Drosophila secondary cell recycling endosomes, but unlike core ESCRTs, they are not involved in degradation of ubiquitinylated proteins in late endosomes. Furthermore, CHMP5 knockdown in human HCT116 colorectal cancer cells selectively inhibits Rab11a-exosome production. Accessory ESCRT-III knockdown suppresses seminal fluid-mediated reproductive signalling by secondary cells and the growth-promoting activity of Rab11a-exosome-containing EVs from HCT116 cells. We conclude that accessory ESCRT-III components have a specific, ubiquitin-independent role in Rab11a-exosome generation, a mechanism that might be targeted to selectively block pro-tumorigenic activities of these vesicles in cancer.

Inter- and Intra-Rater Reliabilities of the Army Combat Fitness Test Three-Repetition Maximum Deadlift Event Among Raters of Varying Professional Experience.

INTRODUCTION: The U.S. Army is updating the physical fitness assessment for soldiers to the six-event Army Combat Fitness Test (ACFT). A paucity of data regarding the ACFT maximum deadlift (MDL) event, especially in military populations, has increased concern over the objectivity of the test. The reliability of scoring the MDL has not been established. It is unknown if grader professional experience impacts the reliability of scoring, and if so, what level of experience is required for reliable assessment. Performance and assessment of the MDL could impact military occupational selection, promotion, and retention within the Army. The purposes of this study were to determine the inter- and intra-rater reliabilities of raters with varying degrees of professional experience on scoring the MDL and to determine the relationships between load lifted, overall lift success, sex, and body mass index (BMI). METHODS: The design is a reliability study. Approval was granted by the Naval Medical Center-Portsmouth Institutional Review Board. Fifty-five healthy soldiers and cadets from the U.S. Military Academy were recruited. Participants completed one data collection session, performing one MDL attempt. The attempt was video recorded using three devices: two handheld tablets placed perpendicular to the sagittal and frontal planes recording at 240 Hz and one digital camera positioned at a 45° angle recording at 30 Hz. A reference standard was established through slow-motion analysis of the sagittal and frontal plane recordings. Six raters with varying degrees of professional experience viewed the 45° camera recordings at real-time speed independently, in a random order, on two separate occasions. Lift success was dichotomously assessed as successful or unsuccessful according to the MDL standards. Cohen's kappa was computed to determine inter- and intra-rater reliabilities among raters. Bivariate correlation was used to assess associations among load lifted, BMI, and sex. A chi-squared test of independence assessed the relationship between sex and overall lift success. RESULTS: Inter-rater reliability between the six raters ranged from 0.29 to 0.69. Inter-rater reliability between the raters to the reference standard ranged from 0.28 to 0.61. Intra-rater reliability ranged from 0.51 to 0.84. Inter-rater reliability of raters who had attended a Training and Doctrine Command-approved ACFT certification course ranged from 0.51 to 0.66, while those who had not ranged from 0.34 to 0.46. BMI and sex were associated with load lifted (r = 0.405, P = .002; r = -0.727, P < .001, respectively). Overall lift success was not associated with load lifted (r = -0.047, P = .731). Overall lift success was not related to sex (χ2 = 0.271, P = .602). CONCLUSION: Inter-rater reliability of the six raters ranged from poor to substantial, while intra-rater reliability ranged from moderate to excellent. Compared to a reference standard, inter-rater reliability ranged from poor to substantial. The wide range in consistency demonstrated in this study, both between and within raters, brings into question the current subjective methods used to grade the MDL. More research is needed to understand the most feasible, valid, and reliable way to assess performance standards like the MDL that may affect a soldier's career progression.

Visual outcomes of macula-involving rhegmatogenous retinal detachment in patients with and without age-related macular degeneration.

BACKGROUND: The prognosis for patients with macula-off rhegmatogenous retinal detachment (RRD) and concomitant age-related macular degeneration (AMD) is not well known. The purpose of this study is to compare visual outcomes in macula-off RRD in eyes with AMD versus a group of comparison eyes without AMD. METHODS: This was a retrospective chart review of 1149 patients. A total of 191 eyes met study criteria, 162 non-AMD eyes (controls), and 29 AMD eyes. The main outcome measure was postoperative visual acuity following pars plana vitrectomy (PPV), scleral buckle (SB), or combined PPV/SB in control eyes versus AMD eyes. This was compared using Fisher's exact test. RESULTS: There was a statistically significant difference in postoperative visual acuity by AMD status, with those without AMD having a worse visual outcome overall (p = 0.0048). A similar percentage of AMD versus non-AMD eyes achieved vision better than 20/40. More patients in the non-AMD group achieved a final visual acuity between 20/40 and 20/200. Of patients with AMD, more had vision worse than 20/200 though 58% maintained functional vision (better than 20/200). Those without AMD had a higher frequency of Count Fingers (CF), Hand Motion (HM), Light Perception (LP), or No Light Perception (NLP) vision (p = 0.023). CONCLUSIONS: Though postoperative visual acuity was worse overall in the non-AMD group with a higher frequency of patients having final vision of CF, HM, LP, or NLP, this is likely a function of the difference in sample size and composition between the two groups. Importantly, this study suggests AMD patients can expect similar outcomes to non-AMD patients after RRD repair. We conclude that AMD patients can achieve functional vision after RRD surgery, similar to those without AMD.

Pax6 mutant cerebral organoids partially recapitulate phenotypes of Pax6 mutant mouse strains.

Cerebral organoids show great promise as tools to unravel the complex mechanisms by which the mammalian brain develops during embryogenesis. We generated mouse cerebral organoids harbouring constitutive or conditional mutations in Pax6, which encodes a transcription factor with multiple important roles in brain development. By comparing the phenotypes of mutant organoids with the well-described phenotypes of Pax6 mutant mouse embryos, we evaluated the extent to which cerebral organoids reproduce phenotypes previously described in vivo. Organoids lacking Pax6 showed multiple phenotypes associated with its activity in mice, including precocious neural differentiation, altered cell cycle and an increase in abventricular mitoses. Neural progenitors in both Pax6 mutant and wild type control organoids cycled more slowly than their in vivo counterparts, but nonetheless we were able to identify clear changes to cell cycle attributable to the absence of Pax6. Our findings support the value of cerebral organoids as tools to explore mechanisms of brain development, complementing the use of mouse models.

Climate change alters impacts of extreme climate events on a tropical perennial tree crop.

Anthropogenic climate change causes more frequent and intense fluctuations in the El Niño Southern Oscillation (ENSO). Understanding the effects of ENSO on agricultural systems is crucial for predicting and ameliorating impacts on lives and livelihoods, particularly in perennial tree crops, which may show both instantaneous and delayed responses. Using cocoa production in Ghana as a model system, we analyse the impact of ENSO on annual production and climate over the last 70 years. We report that in recent decades, El Niño years experience reductions in cocoa production followed by several years of increased production, and that this pattern has significantly shifted compared with prior to the 1980s. ENSO phase appears to affect the climate in Ghana, and over the same time period, we see corresponding significant shifts in the climatic conditions resulting from ENSO extremes, with increasing temperature and water stress. We attribute these changes to anthropogenic climate change, and our results illustrate the big data analyses necessary to improve understanding of perennial crop responses to climate change in general, and climate extremes in particular.

Pax6 limits the competence of developing cerebral cortical cells to respond to inductive intercellular signals.

The development of stable specialized cell types in multicellular organisms relies on mechanisms controlling inductive intercellular signals and the competence of cells to respond to such signals. In developing cerebral cortex, progenitors generate only glutamatergic excitatory neurons despite being exposed to signals with the potential to initiate the production of other neuronal types, suggesting that their competence is limited. Here, we tested the hypothesis that this limitation is due to their expression of transcription factor Pax6. We used bulk and single-cell RNAseq to show that conditional cortex-specific Pax6 deletion from the onset of cortical neurogenesis allowed some progenitors to generate abnormal lineages resembling those normally found outside the cortex. Analysis of selected gene expression showed that the changes occurred in specific spatiotemporal patterns. We then compared the responses of control and Pax6-deleted cortical cells to in vivo and in vitro manipulations of extracellular signals. We found that Pax6 loss increased cortical progenitors' competence to generate inappropriate lineages in response to extracellular factors normally present in developing cortex, including the morphogens Shh and Bmp4. Regional variation in the levels of these factors could explain spatiotemporal patterns of fate change following Pax6 deletion in vivo. We propose that Pax6's main role in developing cortical cells is to minimize the risk of their development being derailed by the potential side effects of morphogens engaged contemporaneously in other essential functions.

Can surgical skills be taught using technological advances online? A comparative study of online and face-to-face surgical skills training.

INTRODUCTION: Online teaching has rapidly emerged as a viable alternative to traditional face-to-face education. How to teach surgical skills in the online environment, however, has not yet been fully established nor evaluated. METHODS: An international 1-day online surgical skills course consisting of lectures, pre-recorded virtual workshops, live demonstrations and along with surgical skills teaching in breakout rooms was organised. Based on existing learning theories, new methods were developed to deliver skills teaching online. Simultaneously, traditional in-person surgical skills teaching was also conducted and used as a benchmark. Skills development was assessed by trained demonstrators and self-reported competency scores were compared between the online and face-to-face event. RESULTS: 553 delegates from 20 different countries attended the online course. Of these, 64 were trained in breakout rooms with a 1:5 demonstrator-to-delegate ratio whilst the remaining 489 delegates participated in didactic skills development sessions. In a separate face-to-face course, 20 delegates were trained with traditional methods. Demonstrators rated the competency of delegates for suturing, tendon repair and vascular anastomosis. There was no significant difference in the competency ratings of delegates receiving online teaching or face-to-face teaching (p = 0.253, p = 0.084, p = 1.00, respectively). The development of the same skills to "articulation" were not different between formats (p = 0.841, p = 0.792, p = 1.00, respectively). Post course self-rated competency scores improved for all technical skills (p < 0.001). Small group sessions, both online and face-to-face, received higher satisfaction ratings compared to large group sessions in terms of clarity of instructions, answers to questions and demonstrator feedback. Overall feedback on teaching quality, however, was equivalent across both groups. DISCUSSION: Online teaching of surgical skills for early training years is an appropriate alternative to face-to-face teaching.

Musculoskeletal Imaging for Low Back Pain in Direct Access Physical Therapy Compared to Primary Care: An Observational Study.

BACKGROUND: Overutilization of diagnostic imaging is associated with poor outcomes and increased costs. Physical therapists demonstrate the ability to order diagnostic imaging safely and appropriately, and early access to physical therapy reduces unnecessary imaging, lowers healthcare costs, and improves outcomes. HYPOTHESIS/PURPOSE: The primary purpose of this study was to compare rates of compliance with the National Committee for Quality Assurance - Healthcare Effectiveness Data and Information Set (HEDIS) recommendations for diagnostic imaging in low back pain between physical therapists and primary care providers in young, athletic patients. STUDY DESIGN: Retrospective cohort study. METHODS: Military Health System Data Repository (MDR) data from January 2019 to May 2020 was reviewed for compliance with the low back pain HEDIS recommendation. The low back pain imaging HEDIS measure identifies the percentage of patients who did not have an imaging study (plain X-ray, MRI, CT Scan) ordered on the first encounter with a diagnosis of low back pain or in the 28 days following that first diagnosis. Chi-square tests compared HEDIS compliance rates, with α = 0.05 set a priori. RESULTS: From January 2019 to May 2020, in patients age 18-24, the MDR database identified 1,845 total visits for LBP identified in the Physical Therapy Clinic and 467 total visits for LBP in the Primary Care Clinic. In the Physical Therapy Clinic, 96.7% of encounters did not have imaging ordered within the first 28 days of onset of symptoms, compared with 82.0% in the Primary Care Clinic (p < .001). CONCLUSIONS: Utilizing data from a national standardized healthcare performance measure, physical therapists practicing in a direct-access setting were significantly more likely than primary care providers to adhere to guidelines for low back pain imaging in young, athletic patients. LEVEL OF EVIDENCE: Level 3.

The Effect of Blood Flow Restriction Training on Muscle Atrophy Following Meniscal Repair or Chondral Restoration Surgery in Active Duty Military: A Randomized Controlled Trial.

CONTEXT: Recently, blood flow restriction (BFR) training has gained popularity as an alternative to high-load resistance training for improving muscle strength and hypertrophy. Previous BFR studies have reported positive treatment effects; however, clinical benefits to using BFR following meniscal repair or chondral surgery are unknown. The purpose of this study was to determine the effect of resistance exercises with BFR training versus exercises alone on self-reported knee function, thigh circumference, and knee flexor/extensor strength postmeniscal or cartilage surgery. DESIGN: Single-blinded randomized controlled trial in an outpatient military hospital setting. Twenty participants were randomized into 2 groups: BFR group (n = 11) and control group (n = 9). METHODS: Participants completed 12 weeks of postoperative thigh strengthening. The BFR group performed each exercise with the addition of BFR. Both groups continued with the prescribed exercises without BFR from 12 weeks until discharged from therapy. Thigh circumference and self-reported knee function were measured at 1, 6, 12, and 24 weeks postoperatively along with knee extensor and flexor strength at 12 and 24 weeks. Change scores between time points were calculated for knee function. Limb symmetry indices (LSI) were computed for thigh circumference and knee strength variables. RESULTS: Seventeen participants were included in the final analyses (BFR = 8 and control = 9) due to COVID-19 restrictions. There were no interactions or main effects for group. Time main effects were established for change in knee function scores, thigh circumference LSI, and knee extensor strength LSI. However, knee flexor strength LSI had no main effect for time. CONCLUSION: The outcomes of this trial suggest that resistance exercises with and without BFR training may result in similar changes to function, thigh atrophy, and knee extensor strength postmeniscus repair/chondral restoration, though further study with larger sample sizes is needed.