Comparison of three-dimensional printed patient-specific guides versus freehand approach for radial osteotomies in normal dogs: Ex vivo model.

OBJECTIVE: To compare the accuracy of three-dimensional (3D) printed patient-specific guide (PSG) with a freehand (FH) approach for radial osteotomies in ex vivo normal dogs. STUDY DESIGN: Experimental study. ANIMALS: Twenty four ex vivo thoracic limb pairs from normal beagle dogs. METHODS: Computed tomography (CT) images were collected preoperatively and postoperatively. Three osteotomies tested (n = 8/group) were: (1) uniplanar 30° frontal plane wedge ostectomy, (2) oblique plane (30° frontal, 15° sagittal) wedge ostectomy, and (3) single oblique plane osteotomy (SOO, 30° frontal, 15° sagittal, and 30° external). Limb pairs were randomized to a 3D PSG or FH approach. The resultant osteotomies were compared with virtual target osteotomies by surface shape-matching postoperative to the preoperative radii. RESULTS: The mean ± standard deviation osteotomy angle deviation for all 3D PSG osteotomies (2.8 ± 2.8°, range 0.11-14.1°) was less than for the FH osteotomies (6.4 ± 6.0°, range 0.03-29.7°). No differences were found for osteotomy location in any group. In total, 84% of 3D PSG osteotomies were within 5° deviance from the target compared to 50% of freehand osteotomies. CONCLUSION: Three-dimensional PSG improved FH accuracy of osteotomy angle in select planes and the most complex osteotomy orientation in a normal ex vivo radial model. CLINICAL SIGNIFICANCE: Three-dimensional PSGs provided more consistent accuracy, which was most notable in complex radial osteotomies. Future work is needed to investigate guided osteotomies in dogs with antebrachial bone deformities.

Intraoperative physician assessment of bone: correlation to bone mineral density.

This study evaluated the intraoperative physician assessment (IPA) of bone status at time of total knee arthroplasty. IPA was highly correlated with distal femur and overall bone mineral density. When IPA identifies poor bone status, formal bone health assessment is indicated. PURPOSE: Intuitively, intraoperative physician assessment (IPA) would be an excellent measure of bone status gained through haptic feedback during bone preparation. However, no studies have evaluated the orthopedic surgeon's ability to do so. This study's purpose, in patients undergoing total knee arthroplasty (TKA), was to relate IPA with (1) the lowest bone mineral density (BMD) T-score at routine clinical sites; and (2) with distal femur BMD. METHODS: Seventy patients undergoing TKA by 3 surgeons received pre-operative DXA. Intraoperatively, bone quality was assessed on a 5-point scale (1 excellent to 5 poor) based on tactile feedback to preparation. Demographic data, DXA results, and IPA score between surgeons were compared by factorial ANOVA. Lowest T-score and distal femur BMD were associated with IPA using Spearman's correlation. RESULTS: The mean (SD) age and BMI were 65.8 (7.6) years and 31.4 (5.1) kg/m2, respectively. Patient demographic data, BMD, and IPA (mean [SD] = 2.74 [1.2]) did not differ between surgeons. IPA correlated with the lowest T-score (R = 0.511) and distal femur BMD (R = 0.603-0.661). Based on the lowest T-score, no osteoporotic patients had an IPA above average, and none with normal BMD was classified as having poor bone. CONCLUSIONS: IPA is highly correlated with local (distal femur) and overall BMD. This study supports the International Society for Clinical Densitometry position that surgeon concern regarding bone quality should lead to bone health assessment. As IPA is comparable between surgeons, it is logical this can be widely applied by experienced orthopedic surgeons. Future studies evaluating IPA at other anatomic sites are indicated.

Quantification of Iliac Arterial Blood Velocity in Stenotic Phantom and Porcine Models Using Quantitative Digital Subtraction Angiography.

PURPOSE: To assess the feasibility of using quantitative digital subtraction angiography (qDSA) to quantify arterial velocity in phantom and porcine stenotic iliac artery models. MATERIALS AND METHODS: Varying stenoses (mild, <50%; moderate, 50%-70%; and severe, >70%) were created in a silicone iliac artery phantom using vessel loops. Two-dimensional digital subtraction angiographies (DSAs) were performed, with velocities calculated using qDSA. qDSA velocities were compared with flow rates and velocities measured with an ultrasonic flow probe. Two-dimensional DSAs of the common and external iliac arteries were then performed in 4 swine (mean weight, 63 kg) before and after a severe stenosis (>70%) was created in the iliac artery using 3-0 silk suture. Peak systolic velocities on pulsed wave Doppler ultrasound (US) before and after stenosis creation were correlated with the qDSA velocities. Pearson correlation, linear regression, and analysis of variance were used for analysis. RESULTS: In the phantom study, ultrasonic probe velocities positively correlated with downstream qDSA (r = 0.65; P < .001) and negatively correlated with peristenotic qDSA velocities (r = -0.80; P < .001). In the swine study, statistically significant reductions in external iliac arterial velocity were noted on US and qDSA after stenosis creation (P < .05). US and qDSA velocities strongly correlated for all flow states with both 50% and 100% contrast concentrations (r = 0.82 and r = 0.74, respectively), with an estimated US-to-qDSA ratio of 1.3-1.5 (P < .001). qDSA velocities with 50% and 100% contrast concentrations also strongly correlated (r = 0.78; P < .001). CONCLUSIONS: In both phantom and swine stenosis models, changes in iliac arterial velocity could be quantified with qDSA, which strongly correlated with standard-of-care US.

Association of in-competition injury risk and the degree of rapid weight cutting prior to competition in division I collegiate wrestlers.

OBJECTIVES: Weight cutting is thought to offer a competitive advantage in wrestling. Dehydration has deleterious effects on physical and cognitive function, which may increase the risk of injury. The purpose of the study was to investigate whether the degree of weight cutting was associated with injury risk. METHODS: Data were collected prospectively in a cohort of collegiate wrestlers over seven seasons. Changes in weight, body fat and lean mass were measured during the preseason, at midseason and before competition. Cox proportional-hazard ratios were calculated for risk of in-competition injury. RESULTS: Among 67 unique division 1 collegiate wrestlers (163 athlete seasons), there were 53 unique injuries affecting 46 athletes. There was no difference in absolute weight change, per cent weight change, per cent body fat change or per cent lean mass change between injured and non-injured wrestlers from the preseason to midseason measurements. From midseason to competition weight, change in body weight was -7.0%±3.2% (-5.3 kg±2.6) in injured athletes compared with -5.7%±3.3% (-4.3 kg±2.5) in non-injured athletes. For every kilogram of body weight lost, wrestlers had a 14% increased hazard of injury (HR 1.14, 95% CI 1.04 to 1.25, p=0.004). For every 1% of body weight lost, wrestlers had an 11% increased hazard of injury (HR 1.11, 95% CI 1.03 to 1.19, p=0.005). CONCLUSION: Rapid weight cutting was associated with a higher risk of in-competition injuries in division 1 collegiate wrestlers. For every per cent in body weight lost, wrestlers had an 11% increased hazard of injury during competition.

Impact of COVID-19 on the physical activity, quality of life and mental health of adolescent athletes: a 2-year evaluation of over 17 000 athletes.

PURPOSE: To evaluate the changes in mental health, quality of life (QOL) and physical activity (PA) among adolescent athletes during the COVID-19 pandemic as organised sports resumed. METHODS: Adolescent athletes completed surveys including demographic and sport participation information, 7-item Generalized Anxiety Disorder, 9-item Patient Health Questionnaire, Pediatric Quality of Life Inventory and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale in May 2020 following COVID-19-related sport cancellations (Spring20) and after returning to sports in May 2021 (Spring21). The groups were balanced by inverse propensity score weighting and compared using analysis of variance models and ordinal regression models. RESULTS: 17 421 participants were included (Spring20=13 002; Spring21=4419; 16.2±1.2 years; 53% female). Anxiety was significantly lower (better) in Spring21 (Spring20=7.0, 95% CI 6.9 to 7.1; Spring21=4.9, 95% CI 4.8 to 5.0, p<0.001), as was the prevalence of moderate to severe anxiety (Spring20=29.4%, Spring21=17.1%, p<0.001). Depression was significantly improved in Spring21 (Spring20=7.6, 95% CI 7.5 to 7.7; Spring21=4.6, 95% CI 4.5 to 4.8, p<0.001), as was the prevalence of moderate to severe depression (Spring20=32.2%, Spring21=15.4%, p<0.001). Athletes in Spring21 reported higher QOL (Spring20=79.6, 95% CI 79.3 to 79.9; Spring21=84.7, 95% CI 84.4 to 85.0, p<0.001) and increased levels of PA (Spring20=13.8, 95% CI 13.6 to 13.9; Spring21=22.7, 95% CI 22.6 to 22.9, p<0.001). CONCLUSION: Early COVID-19 sports restrictions were associated with worsening mental health in adolescents. In 2021, after returning to sports, athletes reported significant improvements in mental health, QOL and PA, although mental health adversities remain an important priority.

Accuracy of pin placement in the canine thoracolumbar spine using a free-hand probing technique versus 3D-printed patient-specific drill guides: An ex-vivo study.

OBJECTIVE: To compare pin placement accuracy, intraoperative technique deviations, and duration of pin placement for pins placed by free-hand probing (FHP) or 3D-printed drill guide (3DPG) technique. SAMPLE POPULATION: Four greyhound cadavers. METHODS: Computed tomography (CT) examinations from T6-sacrum were obtained for determination of optimal pin placement and 3DPG creation. Two 3.2/2.4-mm positive profile pins were inserted per vertebra, one left and one right from T7-L7 (FHP [n = 56]; 3DPG [n = 56]) by one surgeon and removed for repeat CT. Duration of pin placement and intraoperative deviations (unanticipated deviations from planned technique) were recorded. Pin tracts were graded by two blinded observers using modified Zdichavsky classification. Descriptive statistics were used. RESULTS: A total of 54/56 pins placed with 3DPGs were assigned grade I (optimal placement) compared with 49/56 pins using the FHP technique. A total of 2/56 pins placed with 3DPGs and 3/56 pins using the FHP technique were assigned grade IIa (partial medial violation). A total of 4/56 pins placed using the FHP technique were assigned grade IIIa (partial lateral violation). No pins were assigned grade IIb (full medial violation). Intraoperative technique deviations occurred with 6/56 pins placed using the FHP technique and no pins with 3DPGs. Overall, pins were placed faster (mean ± SD 2.6 [1.3] vs. 4.5 [1.8] min) with 3DPGs. CONCLUSIONS: Both techniques were accurate for placement of spinal fixation pins. The 3DPG technique may decrease intraoperative deviations and duration of pin placement. CLINICAL RELEVANCE: Both techniques allow accurate pin placement in the canine thoracolumbar spine. The FHP technique requires specific training and has learning curve, whereas 3DPG technique requires specific software and 3D printers.

Accommodative movements of the choroid in the optic nerve head region of human eyes, and their relationship to the lens.

The ciliary muscle (CM) powers the accommodative response, and during accommodation the CM pulls the choroid forward in the region of the ora serrata. Our goal was to elucidate the accommodative movements of the choroid in the optic nerve region in humans and to determine whether these movements are related to changes in the lens dimensions that occur with aging, in the unaccommodated and accommodated state. Both eyes of 12 human subjects (aged 18-51 yrs) were studied. Homatropine (1 drop/5%) was used to relax the ciliary muscle (unaccommodated or "resting" eye) and pilocarpine was used to induce the maximum accommodative response (2 drops/4%) (accommodated eye). Images of the fundus and choroid were collected in the region of the optic nerve (ON) via Spectralis OCT (infrared and EDI mode), and choroidal thickness was determined. Ultrasound biomicroscopy (UBM; 50 MHz, 35 MHz) images were collected in the region of the lens/capsule and ciliary body. OCT and UBM images were collected in the resting and accommodated state. The unaccommodated choroidal thickness declined significantly with age (p = 0.0073, r = 0.73) over the entire age range of the subjects studied (18-51 years old). The choroidal thickness was significantly negatively correlated with lens thickness in the accommodated (p = 0.01) and the unaccommodated states (p = 0.005); the thicker the lens the thinner the choroid. Choroid movements around the optic nerve during accommodation were statistically significant; during accommodation the choroid both thinned and moved centrifugally (outward/away from the optic nerve head). The accommodative choroid movements did not decline significantly with age and were not correlated with accommodative amplitude. Measurement of the choroidal thickness is possible with the Spectralis OCT instrument using EDI mode and can be used to determine the accommodative changes in choroidal thickness. The choroidal thickness decreased with age and during accommodation. It may be that age-related choroidal thinning is due to changes in the geometry of the accommodative apparatus to which it is attached (i.e., ciliary muscle/lens complex) such that when the lens is thicker, the choroid is thinner. Accommodative decrease in choroidal thickness and stretch of the retina/choroid may indicate stress/strain forces in the region of the optic nerve during accommodation and may have implications for glaucoma.

Femur and Tibia BMD Measurement in Elective Total Knee Arthroplasty Candidates.

Distal femur BMD declines ∼20% following total knee arthroplasty (TKA) potentially leading to adverse outcomes. BMD knowledge before and following TKA might allow interventions to optimize outcomes. We hypothesized that distal femur and proximal tibial BMD could be reproducibly measured with existing DXA technology. Elective TKA candidates were enrolled and standard clinical DXA plus bilateral PA and lateral knee scans acquired. Manual regions of interest (ROIs) were placed at distal femur and proximal tibia sites based on required TKA machining and periprosthetic fracture location. Intra- and inter-rater BMD reliability was assessed by intra-class correlation (ICC). Custom and standard proximal femur BMD were correlated by linear regression and paired t test evaluated BMD differences between planned surgical and contralateral side. One hundred subjects (68F/32M), mean (SD) age and BMI of 67.2 (7.7) yr and 30.8 (4.8) kg/m2 were enrolled. Lowest clinical BMD T-score was < -1.0 in 65% and ≤ -2.5 in 16%; 34 had prior fracture. BMD reproducibility at all custom ROIs was excellent; ICC > 0.96. Mean BMD at custom ROIs ranged from 0.903 to 1.346 g/cm2 in the PA projection and 0.891 to 1.429 g/cm2 in the lateral. Lower BMD values were observed at the proximal tibia, while the higher measurements were at the femur condyle. Custom knee ROI BMD was highly correlated (p < 0.0001) with total and femur neck with better correlation at ROIs adjacent to the joint (R2 = 0.62-0.67, 0.49-0.55 respectively). In those without prior TKA (n = 76), mean BMD was lower (2.8%-6.6%; p < 0.05) in the planned surgical leg at all custom ROIs except the PA tibial regions. Individual variability was present with 82% having a custom ROI with lower BMD (up to 53%) in the planned operative leg. Distal femur and proximal tibial BMD can be measured using custom ROIs with good reproducibility. Suboptimal bone status is common in TKA candidates and distal femur/proximal tibia BMD is often lower on the planned operative side. Routine distal femur/proximal tibial BMD measurement might assist pre-operative interventions, surgical decision-making, subsequent care and outcomes. Studies to evaluate these possibilities are indicated.

The pupil constriction to light is associated with cognitive measures in middle-aged and older adults.

AIMS: The evidence relating the pupil light reflex (PLR) and cognition have been inconsistent. In this cross-sectional study, we evaluated the association between the PLR and cognition in community-dwelling middle-aged and older individuals. METHODS: Pupil reactivity was recorded in a subgroup of 403 participants (mean age 60.7 years, 57.3% females) in an epidemiologic study of aging. Ten pupil parameters were calculated to describe pupil constriction to light stimuli. A principal component analysis (PCA) score was used to calculate an overall performance over four cognitive testings. Linear regression was used to assess the association between pupil parameters and PCA scores, adjusting for age, sex, education, medications, health-related quality of life questionnaire, and systemic and ocular comorbidities. RESULTS: The PCA scores decreased by 0.039 [95% CI (- 0.050, - 0.028)] per year increase in age and were lower in males than females by 0.76 [95% CI (- 0.96, - 0.55)] (p < 0.001). Pupil constriction amplitude in millimeters and the duration from stimulus onset to maximal constriction velocity were significantly associated with cognition after adjusting for (1) age and sex and (2) age, sex, and multiple covariates (p < 0.05). CONCLUSIONS: In this study, we provided moderate evidence suggesting the association between PLR and neuropsychological cognitive measures. The findings suggest the potential of pupil reactivity to serve as a biomarker of brain aging and warrant further longitudinal study to assess if changes in the PLR can predict cognitive decline over time.

Colored Pain Drawing as a Clinical Tool in Differentiating Neuropathic Pain from Non-Neuropathic Pain.

OBJECTIVES: This is a prospective, blinded, case-control study of patients with chronic pain using body diagrams and colored markers to show the distribution and quality of pain and sensory symptoms (aching, burning, tingling, numbness, and sensitivity to touch) experienced in affected body parts. METHODS: Two pain physicians, blinded to patients' clinical diagnoses, independently reviewed and classified each colored pain drawing (CPD) for presence of neuropathic pain (NeuP) vs. non-neuropathic pain (NoP). A clinical diagnosis (gold standard) of NeuP was made in 151 of 213 (70.9%) enrolled patients. RESULTS: CPD assessment at "first glance" by both examiners resulted in correctly categorizing 137 (64.3% by examiner 1) and 156 (73.2% by examiner 2) CPDs. Next, classification of CPDs by both physicians, using predefined criteria of spatial distribution and quality of pain-sensory symptoms, improved concordance to 212 of 213 CPDs (Kappa = 0.99). The diagnostic ability to correctly identify NeuP and NoP by both examiners increased to 171 (80.2%) CPDs, with 80.1% sensitivity and 80.6% specificity (Kappa = 0.56 [95% confidence interval: 0.44-0.68]). The severity scores for pain and sensory symptoms (burning, tingling, numbness, and sensitivity to touch) on the Neuropathic Pain Questionnaire were significantly elevated in NeuP vs. NoP (P < 0.001). CONCLUSIONS: This study demonstrates good performance characteristics of CPDs in identifying patients with NeuP through the use of a simple and easy-to-apply classification scheme. We suggest use of CPDs as a bedside screening tool and as a method for phenotypic profiling of patients by the quality and distribution of pain and sensory symptoms.

Neuraxial Anesthesia Is Associated With Decreased Pain Scores and Post-Anesthesia Care Unit Opioid Requirement Compared With General Anesthesia in Hip Arthroscopy.

PURPOSE: We sought to identify the immediate postoperative differences in opioid use, pain scores, and post-anesthesia care unit (PACU) length of stay (LOS) after hip arthroscopy related to the type of anesthesia used for the surgical procedure. METHODS: Patients undergoing hip arthroscopy for femoroacetabular impingement syndrome with labral tears by a single surgeon at an academic center between October 2017 and July 2019 were reviewed retrospectively. The primary outcome was PACU opioid administration, measured by morphine equivalents. Secondary parameters included total LOS, postincision LOS, PACU LOS, and PACU arrival/discharge pain scores. Analyses conducted were t tests, Wilcoxon rank sum tests, or χ2 tests. RESULTS: A total of 129 patients met inclusion criteria for this study; 54 male and 75 female, with an average age of 28 (±10.1) years. In total, 52 (40.3%) had general anesthesia and 77 (59.7%) had neuraxial anesthesia, including spinal, epidural, and combined spinal-epidural anesthesia, which were intermixed throughout the study period. Intraoperative and PACU opioid administration demonstrated a significant difference in medians. Neuraxial methods required a lower morphine equivalents in both the operating room (30.0 vs 53.9, P = .001) and PACU (18.2 vs 31.2, P = 0.002). Neuraxial anesthesia had lower median PACU arrival and discharge pain scores (0.0 vs. 5.0, P = .001, 3.0 vs. 4.0, P = .013). There was no statistically significant difference in postincision LOS or traction time. General anesthesia was associated with a longer PACU phase 1 time (1.0 vs 1.3 hours, P = .005). No major adverse events such as death, disability, or prolonged hospitalization occurred in either group. CONCLUSIONS: Neuraxial anesthesia use in routine hip arthroscopy was associated with lower immediate postoperative pain scores, lower intraoperative and immediate postoperative opioid requirements, and may be associated with shorter anesthesia recovery time without any major adverse events when compared with general anesthesia. LEVEL OF EVIDENCE: III, Retrospective Comparative Study.

Evaluation of the effect of disposable tonometer cover brand on performance of Tono-Pen Vet in canine eyes.

PRIMARY OBJECTIVE: To evaluate the effect of latex tip cover manufacturer on accuracy and repeatability of Tono-Pen Vet™ in canine eyes. ANIMAL STUDIED: Twelve enucleated globes from six dogs. PROCEDURES: The anterior chamber was cannulated and connected to a calibrated manometer. Intraocular pressure (IOP) measurements were obtained using the Tono-Pen Vet and TONOVET Plus at manometric IOP ranging from 5 to 80 mmHg. At each IOP, the Tono-Pen Vet was used with a new Ocu-Film™ latex tip cover (the only manufacturer-approved brand of cover) followed by a new Softips™ latex tip cover. For comparison, the TONOVET Plus was also used at each IOP with a new disposable rebound probe. Measured IOP values were analyzed by linear regression and intraclass correlation coefficient (ICC). RESULTS: Tono-Pen Vet accuracy was unaffected by tip cover manufacturer or by frequent change in cover. Using ICC analysis, repeatability of measurements using either tonometer was good to excellent at physiologic IOP levels but variably decreased with both devices at supraphysiologic IOP. CONCLUSIONS: Neither tip cover manufacturer nor frequent changes in tip cover adversely affect Tono-Pen Vet accuracy. Measurement repeatability with Tono-Pen Vet and TONOVET Plus is widely variable at supraphysiologic IOP. Therefore, minor changes in IOP >25 mmHg should not be used to make clinical decisions without considering this variability.

Efficacy of combinational therapy using blue light and benzoyl peroxide in reducing Cutibacterium acnes bioburden at the deltopectoral interval: a randomized controlled trial.

BACKGROUND: The purpose of this study was to compare the efficacy of blue light therapy (BLT) and 5% topical benzoyl peroxide (BPO) gel in combination with standard chlorhexidine (CHX) preparation in eradicating Cutibacterium acnes at the deltopectoral interval measured by positive, quantitative culture findings. METHODS: Adult male volunteers were randomized to 1 of 3 treatment groups: BPO, BLT, and BPO followed by BLT. Contralateral shoulders served as matched controls. Volunteers randomized to BPO applied the gel for a total of 5 treatments. In the BLT group, a single 23-minute treatment was administered at an estimated irradiance of 40 mW/cm2 (radiant exposure, 55.2 J/cm2). In the BPO-BLT group, volunteers received both treatments as described earlier. After treatment with either BPO, BLT, or both, a single swab culture was taken from the treatment shoulder. Next, control and treatment shoulders were prepared with CHX, and cultures were taken from each shoulder. Cultures were sent for anaerobic quantitative growth analysis with both polymerase chain reaction and Sanger sequencing confirmation of presumptive C acnes colonies. RESULTS: This study enrolled 60 male volunteers, 20 per group, with no loss to follow-up. After treatment but prior to CHX administration, all culture samples in the BPO group and BLT group grew C acnes. Prior to CHX, 16 samples (80%) in the BPO-BLT group grew C acnes. On quantitative analysis, the BPO group and BPO-BLT group had significantly less growth of C acnes compared with the BLT group after treatment but prior to CHX (P < .05 for each). Following CHX administration, the BPO and BPO-BLT groups had significantly fewer positive culture findings (odds ratios of 0.03 and 0.29, respectively) and less quantity of growth compared with their control arms (P < .05). This was not seen in the BLT group. For quantitative between-group analysis, no significant synergistic effects were seen with BPO-BLT compared with BPO alone (P = .688). There was no difference in side effects between groups. CONCLUSION: The combination of topical BPO and CHX was effective at eliminating C acnes in most cases. BLT alone did not demonstrate effective antimicrobial properties against C acnes at the radiant exposure administered in this study. Combining BPO and BLT did not lead to significant synergistic antimicrobial effects. Both BPO and BLT are safe with few, transient side effects reported. More work is needed to determine whether BLT at higher radiant exposures or serial treatment results in bactericidal effects against C acnes in vivo.

Accuracy and safety of three-dimensionally printed animal-specific drill guides for thoracolumbar vertebral column instrumentation in dogs: Bilateral and unilateral designs.

OBJECTIVE: To evaluate the safety and accuracy of a unilateral three-dimensionally printed animal-specific drill guide (3DASDG) design for unilateral stabilization in the thoracolumbar vertebral column of dogs compared to a bilateral design. STUDY DESIGN: Cadaveric study. SAMPLE POPULATION: Fifty-two corridors in one canine cadaver. METHODS: Two 3DASDG designs with 2 drilling tubes each were created from T8 to L7 vertebrae. Fifty-two corridors were drilled on the right and the left sides by using unilateral and bilateral designs, respectively. Planned and postoperative trajectories (entry point, exit point, angle) were compared to establish the accuracy. Statistical analysis was used for accuracy comparison between designs. Safety was evaluated by using Zdichavsky classification. RESULTS: Unilateral and bilateral drill guide designs were not different for entry point and angle deviations; however, they were different for the exit point deviations. Two corridors breached outside the vertebra. For all guides, mean entry and exit point deviations were less than 1 and 2 mm, respectively. The maximum entry or exit point deviation in both groups was 4.7 mm. The mean angle deviation was <3.5°, and the maximum angle deviation was 9.3°. CONCLUSION: No difference was detected in accuracy of entry points and angle deviations between drill guide designs tested in normal vertebrae. The technique was classified as highly safe. CLINICAL SIGNIFICANCE: A unilateral drill guide design may be a safe alternative to bilateral guides for unilateral stabilization of the thoracolumbar vertebral column in dogs.

Occupational segregation by gender in veterinary specialties: Who we are choosing, or who is choosing us.

OBJECTIVE: Gender demographics vary across specialties including surgery, internal medicine, cardiology, neurology, and oncology. Our objective was to determine whether residency selection or the decision to apply for training drives these differences. STUDY DESIGN: Retrospective cohort study. SAMPLE POPULATION: Matched and unmatched residents lists from Veterinary Internship and Residency Matching Program (VIRMP) from 2011 to 2020. Comparative Data Reports from the American Association of Veterinary Medical Colleges from 2010 to 2019. METHODS: Names for matched and unmatched residents with addresses in the United States or Canada were coded for gender for seven programs: large and small animal surgery, large and small animal medicine, cardiology, neurology, and oncology. Match rate by gender was compared using chi-square tests. Gender demographics of applicants were compared to demographics of graduates using tests of two proportions. RESULTS: No differences were observed between genders for the likelihood of successfully matching into each residency program evaluated except in large animal internal medicine. Women (44.2%) were slightly more likely to match, overall, than men (39.0%, p = .003). The proportions of women applying for residencies overall (70.7%), in large and small animal surgery (66.1%, 62.2%), cardiology (70.2%), and neurology (70.7%) were lower than the proportion of female graduates (79%; p's < .001). CONCLUSION: No evidence for gender bias was detected in the VIRMP resident selection process. Female veterinary graduates seemed less likely to apply for residencies than their male counterparts. IMPACT: Occupational segregation seems to stem from the decision to apply for residency. Interventions aimed at altering gender demographics in specialized medicine should target potential applicants.

CD8ß Depletion Does Not Prevent Control of Viral Replication or Protection from Challenge in Macaques Chronically Infected with a Live Attenuated Simian Immunodeficiency Virus.

We evaluated the contribution of CD8αß+ T cells to control of live-attenuated simian immunodeficiency virus (LASIV) replication during chronic infection and subsequent protection from pathogenic SIV challenge. Unlike previous reports with a CD8α-specific depleting monoclonal antibody (mAb), the CD8ß-specific mAb CD8ß255R1 selectively depleted CD8αß+ T cells without also depleting non-CD8+ T cell populations that express CD8α, such as natural killer (NK) cells and γδ T cells. Following infusion with CD8ß255R1, plasma viremia transiently increased coincident with declining peripheral CD8αß+ T cells. Interestingly, plasma viremia returned to predepletion levels even when peripheral CD8αß+ T cells did not. Although depletion of CD8αß+ T cells in the lymph node (LN) was incomplete, frequencies of these cells were 3-fold lower (P = 0.006) in animals that received CD8ß255R1 than in those that received control IgG. It is possible that these residual SIV-specific CD8αß+ T cells may have contributed to suppression of viremia during chronic infection. We also determined whether infusion of CD8ß255R1 in the LASIV-vaccinated animals increased their susceptibility to infection following intravenous challenge with pathogenic SIVmac239. We found that 7/8 animals infused with CD8ß255R1, and 3/4 animals infused with the control IgG, were resistant to SIVmac239 infection. These results suggest that infusion with CD8ß255R1 did not eliminate the protection afforded to LASIV vaccination. This provides a comprehensive description of the impact of CD8ß255R1 infusion on the immunological composition in cynomolgus macaques, compared to an isotype-matched control IgG, while showing that the control of LASIV viremia and protection from challenge can occur even after CD8ß255R1 administration.IMPORTANCE Studies of SIV-infected macaques that deplete CD8+ T cells in vivo with monoclonal antibodies have provided compelling evidence for their direct antiviral role. These studies utilized CD8α-specific mAbs that target both the major (CD8αß+) and minor (CD8αα+) populations of CD8+ T cells but additionally deplete non-CD8+ T cell populations that express CD8α, such as NK cells and γδ T cells. In the current study, we administered the CD8ß-specific depleting mAb CD8ß255R1 to cynomolgus macaques chronically infected with a LASIV to selectively deplete CD8αß+ T cells without removing CD8αα+ lymphocytes. We evaluated the impact on control of virus replication and protection from pathogenic SIVmac239 challenge. These results underscore the utility of CD8ß255R1 for studying the direct contribution of CD8αß+ T cells in various disease states.

Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update.

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.

Does soccer headgear reduce the incidence of sport-related concussion? A cluster, randomised controlled trial of adolescent athletes.

BACKGROUND: There have been no large randomised controlled trials to determine whether soccer headgear reduces the incidence or severity of sport-related concussion (SRC) in US high school athletes. OBJECTIVE: We aimed to determine whether headgear reduces the incidence or severity (days out from soccer) of SRCs in soccer players. METHODS: 2766 participants (67% female, age 15.6±1.2) (who undertook 3050 participant years) participated in this cluster randomised trial. Athletes in the headgear (HG) group wore headgear during the season, while those in the no headgear (NoHG) group did not. Staff recorded SRC and non-SRC injuries and soccer exposures. Multivariate Cox proportional hazards models were used to examine time-to-SRC between groups, while severity was compared with a Wilcoxon rank-sum test. RESULTS: 130 participants (5.3% female, 2.2% male) sustained an SRC. The incidence of SRC was not different between the HG and NoHG groups for males (HR: 2.00 (0.63-6.43) p=0.242) and females (HR: 0.86 (0.54-1.36) p=0.520). Days lost from SRC were not different (p=0.583) between the HG group (13.5 (11.0-018.8) days) and the NoHG group (13.0 (9.0-18.8) days). CONCLUSIONS: Soccer headgear did not reduce the incidence or severity of SRC in high school soccer players. TRIAL REGISTRATION NUMBER: NCT02850926.

Comparison of outcomes in cataractous eyes of dogs undergoing phacoemulsification versus eyes not undergoing surgery.

OBJECTIVE: To compare outcomes of surgical intervention and nonsurgical management of canine cataracts. METHODS: Records of patients examined for cataracts from January 2007 to February 2018 were divided into two groups: nonsurgical and surgical. The nonsurgical group was further subdivided based on whether the decision not to pursue surgery was elected by owners, or based on ophthalmologist's advice. Inclusion criteria included 6 months of follow-up. Success in the nonsurgical group was defined as a comfortable eye with no potentially painful complications, and success in the surgical group additionally required vision. Time-to-failure (complications) was assessed with Cox proportional hazards models. RESULTS: A total of 72 eyes (41 dogs) were included in the nonsurgical group, and 126 eyes (67 dogs) were surgically treated. There was no difference in gender or age; however, the surgical group had significantly more diabetic eyes (56.3% vs 15.3%; P < .001) and patient eyes with longer follow-up times (median 37.6 months vs 22.1 months; P < .001) than the nonsurgical group. There was no statistically significant difference in complication rates between the nonsurgical group (15/72 [20.8%]) and the surgical group (23/126 [18.3%]; HR: 2.22 [0.97, 5.0]; P = .060). However, the complication rate in the ophthalmologist-led nonsurgical group was significantly greater than in the owner-led nonsurgical group (P = .019) and the surgical group (P = .002). CONCLUSIONS: When using relevant outcomes, whether or not a cataractous eye has surgery does not affect long-term complications; additionally, nonsurgical eyes that are poor surgical candidates have a higher complication rate than eyes deemed suitable for phacoemulsification for which owners elected not to pursue cataract surgery.

Compartment Syndrome in Operatively Managed Pediatric Monteggia Fractures and Equivalents.

BACKGROUND: Acute compartment syndrome (ACS) is not commonly associated with pediatric Monteggia fractures or Monteggia equivalents (MF/ME). The aims of this study were: (1) To document a rate of ACS among children with operatively managed MF/ME, comparing this to the rate of ACS in classically associated Type 3 supracondylar humerus (T3-SCH) fractures at the same institution; (2) To determine which patients with MF/ME are at highest risk for ACS. METHODS: Children ages 2 to 12 with MF/ME requiring operative management at an academic institution over a 14-year period were identified. The Monteggia fractures were characterized using the Bado classification; equivalent injuries were identified according to established criteria. Similarly, all patients with T3-SCH fractures managed over the same period were identified. Record review included demographic, procedural, and radiographic variables. Statistical analysis compared the rates of ACS in both groups and determined risk factors associated with developing ACS in patients with MF/ME. RESULTS: The rate of ACS in MF/ME was 9 of the 59 (15.3%), which was significantly higher than the rate of ACS in T3-SCH fractures 2 of the 230 (0.9%) (P=0.001). Comparing MF/ME with ACS to those without; there was no difference in sex (P=1.00), Bado Type (P=0.683), or Monteggia fracture versus equivalent (P=0.704). MF/ME with preoperative vascular deficits (22.2%) and those undergoing intramedullary fixation of the radius were more likely to develop ACS (P=0.021 and 0.015, respectively), and there was a trend toward higher rates of ACS among MF/ME with preoperative neurological deficits (P=0.064). CONCLUSIONS: Patients with operatively managed MF/ME had a significantly higher rate of ACS compared with patients with T3-SCH fractures. With no predisposition based on Bado classification or Monteggia fracture versus equivalent, all operatively managed MF/ME appear to be at risk for ACS. Patients with preoperative neurovascular deficits and those undergoing intramedullary radial fixation develop ACS at higher rates. Careful assessment of the forearm for signs and symptoms of ACS both before and after fixation is critical. LEVEL OF EVIDENCE: Level III-retrospective case control.