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Introduction: Utilization of the direct anterior approach (DAA) for total hip arthroplasty (THA) has been steadily increasing in recent years. While the DAA may offer some benefits compared to other approaches, there are still risks involved including relatively higher rates of periprosthetic femur fractures, especially when combined with cementless femoral stem use. The purpose of this study is to evaluate the early postoperative femoral complications with a short triple-wedge tapered stem used in primary THA via a DAA., Materials and Methods: A retrospective review was conducted of the arthroplasty registry of our institution from April 2022 to August 2023 to identify patients who underwent a primary THA via a DAA with the Short Medacta Stem (SMS) (Medacta International, Castel San Pietro, Switzerland). Patients were excluded if the stem was used for a revision surgery, they were within 90 days of surgery, or they refused research consent. Inclusion criteria was met in 262 patients (302 hips). Data was collected after reviewing the chart, and reports and radiographic measurements, including Dorr type and canal fit ratios, were obtained from preoperative and postoperative radiographs, respectively., Results: A total of 302 total hips were included, 161 patients were male (53.3%) and 141 were female (46.7%), with an average age of 66.5 years (27-88, +/- 10.7 years). Average follow up was 0.3 years (range, 0.05-1.71 years). The majority of patients had a Dorr B femur (81.7%). The Median stem size used was an 8 (range, 2-15), and 89.4% of those had a collar. Average canal fill ratio was 0.83 (range, 0.43-0.98, +/- 0.07). Overall, there were two Vancouver B2a periprosthetic femoral shaft fractures (0.66%) that required revision surgery to a modular stem. In addition, there were two Vancouver Ag greater trochanteric fractures (0.66%) with acceptable alignment that did not require revision surgery. Demographic information about the patients with femoral complications is summarized in Table I. Average age of patients with femoral complications was 69.5 years, with an average canal fit ratio of 0.88., Conclusion: We found that the triple-wedge implant had a low rate of early femoral complication in primary THA from an anterior approach and is safe for use in THA from a DAA. More follow up is needed to evaluate continuing implant survivorship and patient outcomes.

Abstract: Philipp, NM, Crawford, DA, Cabarkapa, D, and Fry, AC. Strength and power thresholds to identify high and low linear sprint speed performers in collegiate American football players. J Strength Cond Res 38(1): 74-79, 2024-Lower-body strength and power are commonly measured performance qualities across a number of sports. In recent years, more attention has been given to relationships, primarily between lower-body strength and linear speed performance. While still limited, evidence is in agreement that lower-body strength positively contributes to linear speed performance. However, what is less well understood is if there comes a point in an athlete's development, at which, further working on increasing maximal strength may not fully compliment additional gains in speed performance. Within this study, authors aimed to provide practitioners with lower-body strength and power thresholds that can discriminate between slow and fast performers, within a group of collegiate American football players. The sample was further divided into a high-body and low-body weight group, and authors hypothesized that by using logistic regression, supplemented with receiver operator curve analyses, optimal cut-off points (i.e., relative lower-body strength thresholds) that are able to significantly discriminate between slow and fast linear speed performers may be identified. Findings indicate that optimal cut-off scores differed between the groups of athletes, as well as the lower body strength and power tests. All models were able to significantly distinguish between slower and faster performers, and area under the curve values ranged from 0.695 to 0.903. Although thresholds will likely vary based on factors such as sex, training age, and sport, findings from this investigation may be used to benchmark athletes and to further individualize training aimed at improving linear speed performance., (Copyright © 2023 National Strength and Conditioning Association.)

The current study is part of a community engaged planning phase and aimed to identify perceptions related to the prevalence of violent crime, crime contributors, the relationship between the community and law enforcement, and potential interventions and solutions. In March 2021, semistructured interviews were conducted with individuals from five groups who resided or worked in Bessemer, Alabama: (1) Law Enforcement, (2) Residents, (3) Civic Leaders, (4) Community Leaders, and (5) Victims of Crime. Interviews lasted approximately 60 min and were audio recorded, transcribed, and analyzed according to the guidelines of thematic analysis using NVivo 12. Emerging themes were examined in accordance with the CDC Social-Ecological Model: A Framework for Prevention. Participants (N = 18) were 50.0% female and 77.8% African American with an age range of 25-59 (mean = 43.4 years). Themes that emerged related to crime were: (1) impact, (2) contributors, and (3) solutions. Results indicate that impacts of violent crime at the individual level focused on fear, which led to widespread mental health issues. Relationship level impacts included a lack of trust of law enforcement and neighbors, and community level impacts were decreased neighborhood social cohesion as well as decreased safety. At the societal level, the poor reputation of the city was consistently highlighted. For contributors of crime, being a youth under age 30, drugs, and money were discussed as factors at the individual level. At the relationship level, participants mentioned poor parenting and gangs as crime contributing factors to violent crime. Furthermore, contributing issues related to underresourced schools as well as a poor relationship with law enforcement were brought up at the community level. Similarly, poverty was the overarching contributing issue at the societal level. Solutions that emerged included: education and training in life skills, focusing on young people, family/parenting, conflict resolution programs, programs within schools, improved relationships with law enforcement, and inclusive economic opportunities. Intervention plans are discussed that can merge these stakeholder findings with other data sources., (© 2024 Wiley Periodicals LLC.)

Physical activity (PA) is suggested to reduce osteoarthritis pain; however, it may be avoided by patients requiring arthroplasty. Our goal was to investigate objective and patient-reported outcomes as a function of pre-operative PA levels in patients undergoing total knee arthroplasty (TKA). A total of 1941 patients enrolled in a multicenter prospective cohort study investigating a smartphone-based care management platform for self-directed rehabilitation underwent TKA and were included in the analysis. Activity was categorized based on the cohort's step count quartiles into low, moderate, and high pre-operative PA. Pre-operative and post-operative pain, EQ5D5L, KOOS JR, and step counts were compared by ANOVA according to activity group. Pre-operative pain scores increased with the decreasing activity level (all, p < 0.05) and were most improved post-operatively in the low PA group. High PA patients demonstrated the smallest improvements in EQ-5D-5L and KOOS JR. Low and moderate PA patients increased physical activity by three months, reaching 176% and 104% of pre-operative steps; high PA patients did not return to full step counts by one year post-operatively. Patients undergoing TKA who present with higher levels of physical activity report lower levels of pain and higher function pre-operatively but appreciate less improvement up to one year post-operatively. These results may be helpful in appropriate counseling of patient expectations before TKA.

Prostaglandin E2 (PGE2) is a signaling molecule produced by cyclooxygenase-2 (COX-2) that is important in healthy brain development. Anomalies in the COX-2/PGE2 pathway due to genetic or environmental factors have been linked to Autism Spectrum Disorders (ASD). Our previous studies showed that COX-2 deficient (COX-2 - KI) mice exhibit sex-dependent molecular changes in the brain and associated autism-related behaviors. Here, we aim to determine the effect of COX-2 - KI on microglial density and morphology in the developing brain. Microglia normally transition between an amoeboid or ramified morphology depending on their surroundings and are important for the development of the healthy brain, assisting with synaptogenesis, synaptic pruning, and phagocytosis. We use COX-2 - KI male and female mice to evaluate microglia density, morphology, and branch length and number in five brain regions (cerebellum, hippocampus, olfactory bulb, prefrontal cortex, and thalamus) at the gestational day 19 (G19) and postnatal day 25 (PN25). We discovered that COX2 - KI females were affected at G19 with increased microglial density, altered percentage of amoeboid and ramified microglia, affected branch length, and decreased branching networks in a region-specific manner; these effects persisted to PN25 in select regions. Interestingly, while limited changes were found in G19 COX-2 - KI males, at PN25 we found increased microglial density, higher percentages of ramified microglia, and increased branch counts, and length observed in nearly all brain regions tested. Overall, we show for the first time that the COX-2 deficiency in our ASD mouse model influences microglia morphology in a sex- and region- and stage-dependent manner., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 IBRO. Published by Elsevier Ltd. All rights reserved.)

Prostaglandin E2 (PGE2) is a membrane-derived lipid signaling molecule important in neuronal development. Abnormal levels of PGE2, due to environmental insults prenatal development, have been linked to brain pathologies. We have previously shown that the addition of PGE2 to neuroectodermal (NE4C) stem cells affects early stages of neuronal differentiation (day 0-8) including increased stem cell motility, accelerated formation of neurospheres, and elevated calcium levels in growth cones. In this study, we further examine whether PGE2 can influence actin-dependent neuronal morphology in later stages (day 8-12) of NE4C cell differentiation. We show that exposure to PGE2 from the initiation of differentiation increased neurite length and the proportion of neurites that formed axonal loops. We also observed changes in the proportion of turning growth cones as the differentiation progressed, with a reduced likelihood of observing turning (or asymmetrical) growth cones on day 8 and increased odds on days 10 and 12. Moreover, we showed for the first time that the observed changes in cytoskeletal morphology were PGE2/PKA dependent. Interestingly, we also found that PGE2 decreased the total protein levels of the actin-bound form of spinophilin and increased levels of unbound PKA-phosphorylated ser94-spinophilin. Hence, we propose that exposure to PGE2 can destabilize the actin cytoskeleton at various stages of neuronal differentiation due to dissociation of ser94-spinophilin causing changes in neuronal morphology., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

The Army Combat Fitness Test (ACFT) is a multi-event assessment battery designed to determine the combat readiness of U.S. Army personnel. However, for Reserve Officers' Training Corps (ROTC) programs the logistical demands of collegiate life make repeated administration of the ACFT challenging. The present study sought to design and evaluate a single, multimodal exercise tolerance test (METT) capable of serving as a time-efficient proxy measure of combat readiness., Methods: Using a formal instrument design process, we constructed the METT to mimic the demands of the ACFT and assessed its reliability, validity, and responsiveness., Results: The METT demonstrates minimal measurement error (i.e., a 2% coefficient of variation), concurrent validity with the ACFT (R 2 = 0.327, F = 10.67, p < 0.001), the ability to classify cadets who may be at-risk for failing the ACFT (X 2 = 8.16, p = 0.017, sensitivity = 0.878, specificity = 0.667), and appropriate change following a training intervention (5.69 ± 8.9%)., Conclusions: The METT has the potential to provide a means to monitor progress, identify areas for improvement, and guide informed decision-making regarding individualization of cadet combat training plans.

Background: The purpose of this study is to assess the viability of a knee arthroplasty prediction model using 3-view X-rays that helps determine if patients with knee pain are candidates for total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), or are not arthroplasty candidates., Methods: Analysis was performed using radiographic and surgical data from a high-volume joint replacement practice. The dataset included 3 different X-ray views (anterior-posterior, lateral, and sunrise) for 2,767 patients along with information of whether that patient underwent an arthroplasty surgery (UKA or TKA) or not. This resulted in a dataset including 8,301 images from 2,707 patients. This dataset was then split into a training set (70%) and holdout test set (30%). A computer vision model was trained using a transfer learning approach. The performance of the computer vision model was evaluated on the holdout test set. Accuracy and multiclass receiver operating characteristic area under curve was used to evaluate the performance of the model., Results: The artificial intelligence model achieved an accuracy of 87.8% on the holdout test set and a quadratic Cohen's kappa score of 0.811. The multiclass receiver operating characteristic area under curve score for TKA was calculated to be 0.97; for UKA a score of 0.96 and for No Surgery a score of 0.98 was achieved. An accuracy of 93.8% was achieved for predicting Surgery versus No Surgery and 88% for TKA versus not TKA was achieved., Conclusion: The artificial intelligence/machine learning model demonstrated viability for predicting which patients are candidates for a UKA, TKA, or no surgical intervention., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Isolated tibial polyethylene insert exchange (ITPIE) as a treatment for instability and polyethylene wear after total knee arthroplasty (TKA) remains controversial with studies reporting varied results. The purpose of this study is to evaluate the survival and outcomes of ITPIE performed for treatment of instability with or without polyethylene wear after TKA., Materials and Methods: A query of a private practice arthroplasty registry revealed 364 patients (390 knees) treated with ITPIE for instability and/or polyethylene wear after TKA between 1997 and 2019. Mean age was 66.8 years, mean body mass index (BMI) was 33.8 kg/m2, and 59% of patients were female. ITPIE for infection, tibiofemoral aseptic loosening, arthrofibrosis, poor wound healing, and extensor mechanism failure were excluded. All patients had well-fixed and well-aligned components prior to surgery., Results: Mean follow up was 5.9 years. Knee Society Clinical (KSC) scores improved preoperatively from 55 to 76 postoperatively (p <0.001). Thirty knees (7.7%) required re-revision: 15 (3.8%) for ongoing instability, seven aseptic loosening, three infection, two patellofemoral maltracking, one patellar fracture, one metal allergy, and one revised elsewhere for cause unknown. Kaplan-Meier analysis revealed survival of 93.1% (95% CI: ±1.5%) at five years, 84.7% (95% CI: ±3.5%) at 10 years, and 80.5% (95% CI: ±4.4%) at 21 years., Conclusions: ITPIE is a reliable treatment for instability and/or polyethylene wear after TKA in the presence of well-fixed and well-aligned components with good survival and clinical improvement. The less invasive nature and reduced risk for bone loss make it an attractive option versus full revision.

Introduction: For much of recent history, the metal-bearing surface in total knee arthroplasty has not changed much, with cobalt-chromium being the most widely-used material. However, due to the presence of nickel in its composition, much research has been done to develop alternative metal-bearing surfaces for patients with metal sensitivity. Titanium nitride coatings have shown improved performance and resistance to abrasive wear when compared to their counterparts, thus making this material an ideal alternative to current implant technology., Materials and Methods: Rigorous testing was undertaken to analyze the mechanical properties of titanium nitride for use as a coating in orthopedic implants, such as scratch adhesion, hardness, modulus, and wear rates with specialized machinery, including a Tribometer®, Nano Indenter® G200 (KLA Corporation, Milpitas, California), and scratch system., Results: Across all properties tested-abrasive wear resistance, wear resistance, cohesive and adhesive failure load, hardness, and modulus-IBED TiN coatings were shown to be dominant to both uncoated CoCr and uncoated Ti-6Al-4V in a significant manner., Conclusion: The use of IBED TiN coatings offers a way to improve the performance of mechanical components, such as orthopedic implants made from Ti-6Al-4V materials. IBED TiN coatings can enable the use of Ti-6Al-4V as an alternative to CoCr for articulating orthopedic implant devices, such as knee arthroplasty.

Predation risk and prey responses exhibit fluctuations in space and time. Seasonal ecological disturbances can alter landscape structure and permeability to influence predator activity and efficacy, creating predictable patterns of risk for prey (seasonal risk landscapes). This may create corresponding seasonal shifts in antipredator behaviour, mediated by species ecology and trade-offs between risk and resources. Yet, how human recreation interacts with seasonal risk landscapes and antipredator behaviour remains understudied. In South Florida, we investigated the impact of a seasonal ecological disturbance, specifically flooding, which is inversely related to human activity, on interactions between Florida panthers (Puma concolor coryi) and white-tailed deer (Odocoileus virginianus). We hypothesized that human activity and ecological disturbances would interact with panther-deer ecology, resulting in the emergence of two distinct seasonal landscapes of predation risk and the corresponding antipredator responses. We conducted camera trap surveys across southwestern Florida to collect detection data on humans, panthers and deer. We analysed the influence of human site use and flooding on deer and panther detection probability, co-occurrence and diel activity during the flooded and dry seasons. Flooding led to decreased panther detections and increased deer detections, resulting in reduced deer-panther co-occurrence during the flooded season. Panthers exhibited increased nocturnality and reduced diel activity overlap with deer in areas with higher human activity. Supporting our hypothesis, panthers' avoidance of human recreation and flooding created distinct risk schedules for deer, driving their antipredator behaviour. Deer utilized flooded areas to spatially offset predation risk during the flooded season while increasing diurnal activity in response to human recreation during the dry season. We highlight the importance of understanding how competing risks and ecological disturbances influence predator and prey behaviour, leading to the generation of seasonal risk landscapes and antipredator responses. We emphasize the role of cyclical ecological disturbances in shaping dynamic predator-prey interactions. Furthermore, we highlight how human recreation may function as a 'temporal human shield,' altering seasonal risk landscapes and antipredator responses to reduce encounter rates between predators and prey., (© 2023 The Authors. Journal of Animal Ecology © 2023 British Ecological Society.)

Background: Previous studies have reported excellent results with tapered, titanium, porous plasma-sprayed components in patients undergoing uncemented primary total hip arthroplasty (THA). The purpose of this study was to examine survival and clinical results at a minimum 25-year follow-up., Methods: We reviewed all patients who underwent primary THA at our center through 1995 with a specific femoral component that was essentially unchanged since its 1984 introduction, except porous coating was continued circumferentially in 1987, a hydroxyapatite-coated option was offered in 1988, and an offset option was added in 1999. There were 332 patients (396 THA) who had a minimum 25-year follow-up (range, 25 to 37). Mean age at surgery was 48 years (range, 21 to 70 years). Mean follow-up in nonfailed patients was 29 years (range, 25 to 37 years)., Results: There were 31 femoral revisions (7.8%): 9 infections, 3 failures of ingrowth, 5 aseptic loosening, 8 osteolysis well-fixed, 2 periprosthetic fractures, 2 polyethylene wear with trochanteric avulsion, 1 component breakage, and 1 malalignment well-fixed. Kaplan-Meier survival with the endpoint of all-cause stem revision was 94.8% (95% confidence interval: ±0.9%) at 37 years, and with the endpoint of aseptic loosening/failure of ingrowth was 98.7% (95% confidence interval: ±0.5) at 37 years. Harris hip scores improved significantly from 43 preoperatively to 76 most recently., Conclusion: This tapered, titanium, porous plasma spray-coated femoral component continues to demonstrate high long-term survival with a low rate of femoral component revision for any reason or aseptic loosening/failure of ingrowth., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Custom acetabular components are an increasingly utilized reconstructive option in total hip arthroplasty for catastrophic bone loss and acetabular failure. The purpose of this study was to determine the survivorship of such components for reconstruction due to catastrophic bone loss at a minimum 5-year follow-up., Methods: From August 2003 to July 2016, 64 patients (66 hips) underwent acetabular reconstruction with custom triflange components. All hips were classified as Paprosky 3B or 3C. Harris hip scores were analyzed. Overall survivorship was determined by survival analysis., Results: Seventeen patients (18 hips) died prior to returning for 5-year follow-up. One presumed living patient was lost to contact, yielding a cohort of 46 patients (47 hips) who had minimum 5-year follow-up. The mean age was 65 years (range, 46 to 85), mean body mass index was 29.4 (range, 18 to 45), and 72% were women. Mean follow-up was 8 years (range, 5 to 16). There were 3 revisions of the triflange device (6.4%) due to infection. Survivorship to end point of triflange removal for any reason was 94.1% (95% confidence interval: ±3.4%) at a mean of 16 years. In the overall series (n = 66), there were 9 (13.6%) additional reoperations as follows: 5 incision and debridements, one open reduction internal fixation, two stem revisions for periprosthetic femoral fracture, and one head revision. Harris hip scores improved significantly from a mean of 41 points preoperatively to 64 points postoperatively., Conclusions: Custom acetabular triflange components represent a highly effective tool in a surgeon's armamentarium. These devices are extremely helpful in managing catastrophic bone loss and have a good mean 16-year survival., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Precise indications for medial unicondylar knee arthroplasty (UKA) continue to be defined. It is unclear if patients who have proximal tibia vara should be considered candidates for UKA. The purpose of this study was to evaluate the impact of proximal tibial varus alignment on outcomes after UKA., Methods: A retrospective review identified 2,416 patients (3,029 knees) who underwent mobile-bearing medial UKA with 2-year minimum follow-up or revision. Preoperative radiographs were evaluated, and medial proximal tibial angle (mPTA) was measured. Patients were grouped into two groups as follows: mPTA <80 degrees and mPTA ≥80 degrees. Analyses were performed on the impact of mPTA on clinical outcomes, all-cause revisions, and tibial failures., Results: At a mean follow-up of 5 years (range, 0.5 years to 12.8 years), there was not a statistically significant difference in clinical outcomes nor increased risk for all-cause revision or tibial failure in patients who had an mPTA <80°. Mean mPTA in patients who had tibial failures was 82.5° and not significantly different than those who did not have a tibial failure (82.9°) (P = .289). Tibial failure rate in knees with an mPTA <80° was 2.2% and not significantly different than knees with an mPTA ≥80° at 1.4% (P = .211). The all-cause revision rate in knees with an mPTA <80° was 5.8% and was not significantly different than knees with an mPTA ≥80° at 4.9% (P = .492)., Conclusion: Patients who have tibia vara are not at increased risk for tibial related or all-cause failure in medial UKA. This data may allow surgeons to increase their indications for medial UKA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Medial unicompartmental knee arthroplasty (UKA) is a successful treatment for antero-medial osteoarthritis. However, there are few published studies on the long-term survival of this procedure. The purpose of this study was to review the 15-year minimum outcomes and survival of a mobile-bearing medial UKA., Methods: A retrospective review was performed between July 2004 and December 2006 of all patients who underwent a medial UKA eligible for a minimum of 15-year follow-up. The initial query revealed 299 patients (349 knees). One hundred-seventeen patients died or were lost to follow-up, leaving 182 patients (219 knees) for analyses. Clinical outcomes and survivorship were analyzed., Results: There were 59 implant-related reoperations which occurred at a mean of 10 years (range, 0 to 16 years). The most common reasons for reoperation were arthritic progression (9.1%) and aseptic loosening (9.1%). The 10-year survival with revision to TKA was 89% (95% confidence interval: 86% to 92.4%), and the 15-year survival was 84.1% (95% confidence interval: 80.3% to 88%). There were no statistically significant differences in survival between sex, body mass index, and age. Patients who were not revised had statistically significant improvements in knee range of motion and Knee Society scores., Conclusions: This study found similar long-term survival of a medial mobile-bearing UKA to published total knee arthroplasty outcomes. The implant evaluated in this study has undergone subsequent improvements in instrumentation and design. Further analyses should be performed on the long-term outcomes of the current implant platform., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The rise in demand of knee arthroplasty has led the industry to develop methods to decrease costs of care, such as novel methods of delivering physiotherapy, including smartphone-based exercise educational platforms. The purpose of this study was to determine the noninferiority of one such system after primary knee arthroplasty as compared to traditional in-person physiotherapy., Methods: A prospective, multicenter randomized clinical trial was conducted comparing standard of care rehabilitation to a smartphone-based care platform after primary knee arthroplasty from January 2019 to February 2020. One-year patient outcomes, satisfaction scores, and utilizations of health care resources were analyzed. A total of 401 patients was available for analysis-241 in the control and 160 in the treatment group., Results: There were 194 (94.6%) patients in the control group who required 1 or more physiotherapy visits compared to only 97 (60.6%) patients in the treatment group (P < .001). Emergency department visits within 1 year occurred in 13 (5.4%) patients and 2 (1.3%) patients in the control and treatment groups, respectively (P = .03). The change in mean Knee Injury and Osteoarthritis Outcome Score for joint replacement scores at 1 year was similar between both the groups (32.1 ± 1 6.8 versus 30.1 ± 18.1, P = .32)., Conclusion: Implementation of this smartphone/smart watch care platform showed similar outcomes to traditional care models at 1 year postoperative. Traditional physiotherapy and emergency department visits occurred at much lower rates in this cohort, which could alleviate the need for health care dollars spent by reducing postoperative costs and enhancing communication across the health care system., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Non-traditional physical education (PE) programs may facilitate functional movement patterns and develop fitness and work capacity to facilitate long-term physical activity. This program evaluation study compared changes in body composition, movement competency, work capacity, and fitness for high school students in CrossFit or weight training PE; both classes were hypothesized to improve each area, with greater improvements in the CrossFit class. Students participated in 57 min classes 4 days per week for 9 months. Measures including body composition, movement competencies (squat, lunge, push-up, pull-up, hinge, and brace), work capacity (two CrossFit workouts), and fitness (air squats, push-ups, inverted row, plank hold, horizontal and vertical jumps, 5 rep max back squat and press, 500 m bike, and 12 min run) were taken at baseline, midpoint, and post-test. Focus groups to assess students' experiences and outcomes were conducted at post-test. Students significantly improved in movement competencies ( ps = 0.034 to <0.001), work capacity ( ps < 0.001), and all fitness tests ( ps = 0.036 to <0.001). The CrossFit class was only superior on the 500 m bike. Four themes were identified from the focus groups: (1) increased self-confidence, (2) health improvements, (3) newfound community, and (4) translational sports improvements. Future research should examine changes using an experimental design., Competing Interests: The authors declare no conflict of interest.

Background and Purpose: Healthy aging allows older adults to remain active in their communities; however, sedentary behaviors can lead to physical deconditioning and decreased physical function. Structured exercise programs are recommended to facilitate activity engagement and prevent muscle atrophy due to aging to facilitate older adults' abilities to complete activities of daily living. In particular, high-intensity functional training (HIFT) is a multicomponent group exercise program that has previously been shown to increase physical function for middle-age cancer survivors. This study examined the preliminary feasibility and effectiveness of HIFT for improving physical function and participation in physical activity for community-dwelling older adults., Methods: The 8-week pilot study included two 60-minute HIFT sessions per week. Participants (n = 8) were 75% female with a mean age of 71 (6) years. Study initiation, adherence, and acceptability were assessed to determine feasibility. Effectiveness was assessed via 5 physical function measures conducted during sessions 1 and 16 and included the Timed Up and Go, lift and carry test, chair stand test, a repeated stair climb test, and the 6-minute walk test. Participants also self-reported confidence and difficulty for activities of daily living via the Outpatient Physical Therapy Improvement in Movement Assessment Log and physical activity participation via the Community Health Activities Model Program for Seniors questionnaire., Results and Discussion: The study recruitment rate was 88.9% and 87.5% of participants adhered. Intervention acceptability was promising, as 4 participants reported liking multiple aspects of the intervention (eg, coaching/supervision and similar age peers). Intervention effectiveness was promising with significant improvement in 1 of 5 physical function measures, although clinical effects were most likely trivial. Participants reported increased participation in both leisure and structured physical activities., Conclusions: HIFT appeared feasible and showed promise for counteracting the loss of physical function and sedentary behaviors associated with aging. Results should be confirmed in a longer, fully powered study., Competing Interests: The authors declare that they have no conflicts of interest to disclose., (Copyright © 2019 Academy of Geriatric Physical Therapy, APTA.)

Background: Total joint arthroplasty is rapidly shifting to the outpatient space. One of the challenges of same-day discharge adoption has been determining which patients are suitable candidates. Risk assessment tools have been developed, including the Outpatient Arthroplasty Risk Assessment (OARA) score. The purpose of this study was to assess its predictive utility., Methods: A retrospective review was performed on all total joint arthroplasties performed at a single ambulatory surgery center in 2018, yielding a cohort of 1,105 patients (1,332 arthroplasties). The institution's outpatient criteria required optimization of all medical conditions; if the patient had no failing organ, they were candidates for same-day discharge. OARA scores were calculated based on preoperative histories and physical examinations. Analyses were performed on the statistical utility of the OARA score in predicting successful same-day discharge. The mean age was 59 years (range, 27-82), the mean body mass index was 33.3 kg/m 2 (range, 16-66), and 51.5% were women. A total of 45% of patients had one or more major comorbidity., Results: There were 81.6% of patients who had an acceptable OARA score (<60). In addition, 97% of patients who had an "unacceptable" OARA score were successfully discharged the same day. There were 23 patients who required inpatient observation; of these, 7 (30.4%) had an OARA score ≥60., Conclusion: The OARA score was accurate in predicting patients who successfully had same-day discharge but poor at predicting who would not. This system is time consuming and may be too restrictive on which patients are candidates for outpatient arthroplasty. Surgeons may consider a more simplified criteria for outpatient arthroplasty., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Total knee arthroplasty (TKA) is typically performed to restore a neutral mechanical alignment. Recently, there has been increased interest in kinematic alignment to restore the patient's individual alignment. The purpose of this study is to determine if kinematic balancing reduces the need for intraoperative soft tissue releases and rates of manipulation under anesthesia compared to mechanical alignment., Materials and Methods: A query was performed between January 2021 and July 2022 to identify all patients who underwent a primary TKA that was performed with kinematic alignment (KA), which revealed 97 patients (107 TKAs). A cohort of consecutive patients from the preceding six months was gathered of patients who underwent primary TKA with mechanical alignment (MA). This cohort consisted of 199 patients (223 TKAs), yielding a total study cohort of 296 patients (330 knees). Mean age was 64.7 years, mean body mass index (BMI) was 33.1 kg/m2, and 57.1% of patients were female. Rates of manipulation under anesthesia and intraoperative release status were analyzed., Results: Average range of motion preoperatively improved from 108.9° to 114.4° in the KA group but decreased from 112.3° to 109.9° in the MA group at six weeks (p<0.0001). Three of 107 knees (2.8%) required an additional pie-crusting of the superficial MCL in the KA group, whereas 58 of 223 knees (26.0%) did in the MA group (p<0.0001). Three of 107 knees (2.8%) in the KA group and 24 of 223 knees (10.8%) in the MA group required MUA (p<0.0001)., Conclusion: Kinematic alignment significantly reduced the need for intraoperative soft tissue releases and postoperative manipulation under anesthesia. Further studies of the influence of kinematic alignment on these outcomes across multiple surgeons should be performed and/or compared to mechanical alignment.

Introduction: A primary total knee arthroplasty (TKA) system was introduced with a modern universal femoral design with a wide range of size and constraint options to accommodate a variety of patient anatomy, while incorporating streamlined instrumentation for maximum operating room efficiency and economy. The purpose of this study is to review the early clinical outcomes and survivorship at minimum two-year follow up with this knee system., Materials and Methods: From September 2015 to December 2019, 797 patients (1004 knees) underwent primary total knee arthroplasty (TKA) at our center with the TJO Klassic® Complete Primary Knee System (Total Joint Orthopedics Inc., Salt Lake City, Utah) with ultracongruent bearings and were available for study with minimum two-year follow up. All office and hospital records were reviewed for patient demographics, preoperative and postoperative clinical assessments, including range of motion, Knee Society Scores (KSS), University of California at Los Angeles (UCLA) activity scales, complications, and reoperations., Results: Mean follow up was 3.1 years (range, 2-6; standard deviation [SD] ±1.0). There were 471 female patients (59%) and 326 male patients (41%). Mean age at surgery was 69.3 years and mean body mass index was 32.9kg/m2. An all-polyethylene tibial component was used in 305 knees (30.4%) while a modular titanium tibial baseplate with polyethylene insert was used in 699 (69.6%). The patella was left unresurfaced in 381 knees (37.9%). KS scores, including pain component, clinical, and functional, as well as UCLA scores, all improved significantly (p<0.001). Two patients (3 knees) underwent revision. One patient required two-staged revision for treatment of infection in both knees, and one patient required patellar revision for aseptic loosening. Kaplan-Meier survival at 6.2 years was 98.4% (95% CI: ±0.97%) to endpoint of revision of any part for any cause and 99.6% (95% CI: ±0.36%) to endpoint of aseptic revision., Conclusions: At early minimum two-year follow up, this modern universal complete knee system used with ultracongruent bearings demonstrates excellent clinical outcomes and survival.

Acetabular reamers are a mainstay in the preparation of the acetabulum in total hip arthroplasty. Many surgeons, however, have noticed a discrepancy in the preparation of the socket and the reported size of reamers during this crucial phase of the procedure. A cross-sectional study performed by measuring a variety of sets of acetabular reamers was performed. The results showed that 17 of 21 sizes (81%) measured at least 2mm less than their reported size. Given that these differences beget unintended consequences, the industry may consider replacing or sharpening reamers already in use or even switching to a single-use reamer model.

Studies of animal abundance and distribution are often conducted independently of research on movement, despite the important links between processes. Movement can cause rapid changes in spatial variation in density, and movement influences detection probability and therefore estimates of abundance from inferential methods such as spatial capture-recapture (SCR). Technological developments including camera traps and GPS telemetry have opened new opportunities for studying animal demography and movement, yet statistical models for these two data types have largely developed along parallel tracks. We present a hierarchical model in which both datasets are conditioned on a movement process for a clearly defined population. We fitted the model to data from 60 camera traps and 23,572 GPS telemetry locations collected on 17 male white-tailed deer in the Big Cypress National Preserve, Florida, USA during July 2015. Telemetry data were collected on a 3-4 h acquisition schedule, and we modeled the movement paths of all individuals in the region with a Ornstein-Uhlenbeck process that included individual-specific random effects. Two of the 17 deer with GPS collars were detected on cameras. An additional 20 male deer without collars were detected on cameras and individually identified based on their unique antler characteristics. Abundance was 126 (95% CI: 88-177) in the 228 km 2 region, only slightly higher than estimated using a standard SCR model: 119 (84-168). The standard SCR model, however, was unable to describe individual heterogeneity in movement rates and space use as revealed by the joint model. Joint modeling allowed the telemetry data to inform the movement model and the SCR encounter model, while leveraging information in the camera data to inform abundance, distribution and movement. Unlike most existing methods for population-level inference on movement, the joint SCR-movement model can yield unbiased inferences even if non-uniform sampling is used to deploy transmitters. Potential extensions of the model include the addition of resource selection parameters, and relaxation of the closure assumption when interest lies in survival and recruitment. These developments would contribute to the emerging holistic framework for the study of animal ecology, one that uses modern technology and spatio-temporal statistics to learn about interactions between behavior and demography., (© 2021 The Ecological Society of America.)

Background: Use of metal-on-metal (MoM) articulations in total hip arthroplasty (THA) has sharply declined due to high failure rates from metal-related complications. Although certain MoM designs have demonstrated only 46% survival, not all MoM designs have performed the same. The purpose of this study is to evaluate mid-term to long-term survival of a specific MoM implant with a modular titanium taper adapter., Methods: A retrospective review was performed on all patients who underwent primary THA at our center with the M 2 a-Magnum system (Zimmer Biomet, Warsaw, IN). Of 829 patients (956 hips) identified, 754 patients (869 hips) met inclusion criteria of signed research consent, minimum 2-year follow-up, and/or any revision surgery., Results: Mean follow-up was 11.0 years (range 2-16; ±3.5). Mean cup angle of inclination was 42.8° (range 24°-70°, ±6.3°), with 88.0% reconstructed within the 40° ± 10° safe zone. There were 64 revisions (7.36%): 7 (0.81%) septic and 57 (6.56%) aseptic. Of those, 32 (3.68%) were adverse reactions to metal debris. Kaplan-Meier survival free of revision for all causes was 88.6% at 16 years (95% confidence interval 86.8-90.4). Univariate analysis of risk factors for all-cause, aseptic, and adverse reaction to metal debris revision found no relationship with female gender, age ≥65 years, body mass index >30 kg/m 2 , higher activity level, or inclination angle outlier., Conclusion: The results of this study demonstrate a more favorable mid-term to long-term survivorship with this specific MoM implant compared to other designs. Although our institution no longer performs MoM THA, further investigation into differences in MoM implant designs is warranted., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Survivorship of total hip arthroplasty (THA) in younger patients is concerning given the inverse relationship between age and lifetime risk for revision. The purpose of this study is to determine if risk of revision has improved for patients aged 55 years or younger who undergo primary THA using modern polyethylene liners., Methods: A retrospective review identified 2,461 consented patients (2,814 hips) with minimum 2-year follow-up who underwent primary THA at our institution between September 2007 and August 2014 using components from a single manufacturer (Zimmer Biomet), all with vitamin E-infused highly crosslinked polyethylene acetabular inserts. There were 561 patients (643 THA; 23%) aged 55 or younger and 1,900 (2,171 THA; 77%) older than 55., Results: Mean follow-up was 5.0 years for both groups. There were more male patients in the younger (55%) than older (41%) group. Body mass index (BMI) was higher in younger patients independent of gender. Improvement in Harris hip score (HHS) was similar between groups. Kaplan-Meier survival to endpoint of all cause revision was similar between groups at 12 years (P = .8808) with 97.5% (95% CI: ±0.7%) for younger versus 97.1% (95% CI: ±0.6%) for older patients. Most frequent reason for revision overall was periprosthetic femoral fracture (21; 0.75%); univariate analysis revealed risk factors were female gender (P = .28) and age ≥65 years (P = .012)., Conclusion: Use of modern polyethylene, such as vitamin E-stabilized highly cross-linked, liners during THA may improve survivorship in younger patients undergoing THA. Younger patients undergoing primary THA with highly cross-linked polyethylene liners had no increased rate of revision at mid-term follow-up., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate the correlation between objective knee range of motion (ROM) and patient "happiness" with knee ROM after total knee arthroplasty., Methods: This was a retrospective review of all primary total knee arthroplasties from June through December 2019, yielding 902 patients (1,009 knees). Records were reviewed for knee ROM preoperatively and postoperatively at 6-week follow-up as well as whether patients self-reported being "Happy with their ROM" (HWROM). Clinical records were reviewed for documents ROM as well as manipulation under anesthesia (MUA)., Results: The mean preoperative ROM was 110 ± 16 degrees, and 40% of patients were happy with their ROM. Postoperatively, the mean ROM was 106 ± 13 degrees (P < .001), and 76% of patients were HWROM (P < .001). The mean change in knee ROM was (-) 5 ± 17 degrees. The mean postoperative ROM and change in ROM of patients who were HWROM after surgery were 109 ± 12 degrees and (-)2 ± 16 degrees. In patients not HWROM postoperatively, the mean ROM and change in ROM were 98 ± 14 degrees and (-)12 ± 18 degrees (P < .001). Patients with a lower preoperative ROM were statistically significantly more likely to have a positive change in their HWROM (f ratio = 41, P < .001). MUAs were performed in 7.2% of knees, and 28% of patients who underwent an MUA were HWROM before MUA., Conclusion: Early postoperative knee ROM was correlated with patient HWROM. However, further longer term follow-up and more detailed analysis of patient happiness with ROM are needed., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The purpose of this study is to report midterm outcomes and survivorship of a bicruciate retaining knee arthroplasty compared with a bicruciate sacrificing anterior stabilized knee arthroplasty., Methods: A retrospective comparative cohort analysis was performed of all patients who underwent primary total knee arthroplasty with the bicruciate retaining (XP) knee arthroplasty compared with an anterior stabilized (AS) cruciate sacrificing bearing. The XP system was used in 195 knees and was compared with 1471 knees in which the AS bearing was used. Patients were included in analysis if they had minimum 2-year follow-up or had a revision at any point. Preoperative and postoperative range of motion, Knee Society Scores, complications, and reoperations were evaluated. Unpaired t-test and chi-square analysis were performed. Kaplan-Meier survival analysis was performed for all-cause and aseptic survival., Results: At an average of 5.2-year follow-up, 22 (11.3%) XP knees had been revised, compared with 23 (1.6%) AS knees (P < .001). Nineteen (9.7%) XP knees were revised for aseptic tibial loosening; one (0.1%) of the AS knees was revised for the same (P < .001). Nineteen of the XR revision surgeries (86.4%) were for aseptic tibial loosening. Compared with AS knees, the XP knees had significantly lower improvement in range of motion (3.2 deg vs 2.2 deg, P < .001), Knee Society (KS) pain scores (39 vs 35.7, P = .014), KS clinical scores (52.4 vs 46, P < .001), and KS functional scores (20.9 vs 15.5, P = .01)., Conclusion: The bicruciate retaining Vanguard XP Total Knee System demonstrated an unacceptably high rate of aseptic tibial loosening without conferring the benefit of improved postoperative function relative to other available bearings., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Many strategies have been employed to improve operating room efficiency when performing total knee arthroplasty. The goals of efficiency improvements are to decrease operative time and reduce healthcare expenses while providing patients the best quality surgical care. Single-use disposable instruments are one technique to accomplish efficiency. The authors describe their experience with a specific implant manufacturer's disposable single-use instruments for total knee arthroplasty and analyze the cost and time savings compared to traditional instrumentation. Single-use disposable instruments are a viable option to improve OR efficiency, decrease sterile processing burden, and ensure sterile instrumentation for total knee arthroplasty. Furthermore, cost savings can be realized based on an institution's sterile processing expenses and whether the manufacturer or facility covers the cost of the single-use instruments.

Over the last few years, researchers and sport scientists have expressed an increased interest in the effects of interlimb asymmetry on aspects of sport performance such as jumping, sprinting, and changing direction. This study aimed to evaluate the diagnostic utility of three different means of classifying asymmetry to highlight if a 6-week resistance training intervention can meaningfully reduce levels of asymmetry, and to determine the relation between asymmetry reduction and improvements in change of direction (CoD) performance, if any. Eighteen, division-two collegiate American football skill position players completed all pre- and post-intervention procedures. These procedures involved the completion of the Bulgarian Split Squat (BSS) exercise from which asymmetries in relative average power (Rel.AP), and relative peak power (Rel.PP) were derived. Additionally, participants completed three repetitions within the 505 and L-drill tests to quantify CoD performance. Results from our study show that participants classified as asymmetrical, exhibiting observed asymmetry in Rel.PP scores larger than the sample mean plus one standard deviation, had the greatest likelihood of reducing asymmetry (OR = 6.99, 95% CI: 1.4, 12.5) and improving L-drill performance (OR = 1.33, 95% CI: -2.1, 4.8). Further, our training intervention meaningfully reduced Rel.AP asymmetry ( p = 0.027, Cohen's d = 0.73). At the group level, these reductions in asymmetry were accompanied by improvements in L-drill performance that were larger than the sample smallest worthwhile change (SWC). At the individual level, however, change scores in asymmetry and change scores in CoD performance only showed small, non-significant correlations.

Fear of the human 'super predator' has been demonstrated to so alter the feeding behavior of large carnivores as to cause trophic cascades. It has yet to be experimentally tested if fear of humans has comparably large effects on the feeding behavior of large herbivores. We conducted a predator playback experiment exposing white-tailed deer to the vocalizations of humans, extant or locally extirpated non-human predators (coyotes, cougars, dogs, wolves), or non-predator controls (birds), at supplemental food patches to measure the relative impacts on deer feeding behavior. Deer were more than twice as likely to flee upon hearing humans than other predators, and hearing humans was matched only by hearing wolves in reducing overall feeding time gaged by visits to the food patch in the following hour. Combined with previous, site-specific research linking deer fecundity to predator abundance, this study reveals that fear of humans has the potential to induce a larger effect on ungulate reproduction than has ever been reported. By demonstrating that deer most fear the human 'super predator', our results point to the fear humans induce in large ungulates having population- and community-level impacts comparable to those caused by the fear humans induce in large carnivores., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The purpose of this study is to determine if a fellow's involvement, as well as duration of a fellow's training, impacts complications, outcomes, and survivorship in primary total knee arthroplasty (TKA). A retrospective review identified 2,790 consecutive patients (3,530 knees) who underwent primary TKA between 2003 and 2008. A 2-year minimum follow-up was available on 2,785 knees (2,195 patients). Operative data, clinical outcomes, complications, and survivorship were compared between cases with and without a fellow involved as well as comparing cases in the first quarter (Q1) of the academic year to the last three quarters (Q2-4). Mean follow-up was 9.7 years. Fellows were involved in 1,434 (41%) surgeries. Fellow cases had significantly longer tourniquet times (59.5 vs. 49 minutes, p  < 0.001) and operative times (82.4 vs. 70.8 minutes, p  < 0.001). Overall, there was no difference in clinical, functional, or pain outcomes between attending and fellow cases. Fellow cases during Q1 had significantly worse pain scores ( p  = 0.009) and clinical scores ( p  < 0.001). Revision rate, infection rates, and survivorship were not significantly different between fellow and attendings or during Q1 of fellowship compared with attendings. Primary TKA survivorship and complications were not affected by fellow involvement or academic quarter. An "August Effect" may be suggested for clinical and pain outcomes in the first 3 months of fellowship., Competing Interests: K. R. B. and A. V. L. receives royalties from Zimmer Biomet, Innomed; are paid consultants for Zimmer Biomet, Total Joint Orthopaedics; and has minority interest in SPR Therapeutics, Elutibone, Joint Development Corporation., (Thieme. All rights reserved.)

Heart rate variability (HRV) may be useful for prescribing high-intensity functional training (HIFT) exercise programs. This study aimed to compare effects of HRV-guided and predetermined HIFT on cardiovascular function, body composition, and performance., Methods: Recreationally-active adults ( n = 55) were randomly assigned to predetermined HIFT ( n = 29, age = 24.1 ± 4.1 years) or HRV-guided HIFT ( n = 26, age = 23.7 ± 4.5) groups. Both groups completed 11 weeks of daily HRV recordings, 6 weeks of HIFT (5 d·week-1), and pre- and post-test body composition and fitness assessments. Meaningful changes in resting HRV were used to modulate (i.e., reduce) HRV-guided participants' exercise intensity. Linear mixed models were used with Bonferroni post hoc adjustment for analysis., Results: All participants significantly improved resting heart rate, lean mass, fat mass, strength, and work capacity. However, no significant between-groups differences were observed for cardiovascular function, body composition, or fitness changes. The HRV-guided group spent significantly fewer training days at high intensity (mean difference = -13.56 ± 0.83 days; p < 0.001)., Conclusion: HRV-guided HIFT produced similar improvements in cardiovascular function, body composition, and fitness as predetermined HIFT, despite fewer days at high intensity. HRV shows promise for prescribing individualized exercise intensity during HIFT.

Background: Thigh pain following a well-fixed total hip arthroplasty (THA) remains problematic and a source of patient dissatisfaction. The purpose of this study is to evaluate if the development of distal femoral cortical hypertrophy (DFCH) is associated with postoperative thigh pain after THA., Methods: All patients who underwent an uncomplicated primary THA via a direct anterior approach with the Taperloc Microplasty (Zimmer Biomet, Warsaw, IN, USA) implant between 2011 and 2015 were mailed a pain drawing questionnaire. Radiographs were reviewed at 1 year minimum to determine cortical thickness change from immediate post-op. Thigh pain was compared to DFCH. 293 patients were included in the study., Results: Mean follow-up was 3.2 years. A total of 218 hips (74%) had cortical hypertrophy in Gruen zone 3 and 165 hips (56%) had cortical hypertrophy in Gruen zone 5. 52 hips (18%) had ⩾25% cortical hypertrophy in zone 3 and 91 hips (31%) had ⩾25% cortical hypertrophy in zone 5. A total of 44 patients (15%) reported anterior thigh pain and 43 patients (15%) reported lateral thigh pain. Development of DFCH in either Gruen zone 3 or 5 was not associated with anterior or lateral thigh pain. Stem size was positively correlated with zone 3 hypertrophy and inversely related to zone 5 hypertrophy. Thigh pain was not associated with patient age, gender, activity level or stem size., Conclusions: The development of distal femoral cortical hypertrophy after THA with a short stem implant was high, but not associated with patient-reported anterior or lateral thigh pain.

Ligament balancing in revision knee arthroplasty is crucial to the success of the procedure. The medial collateral ligament and lateral ligament complex are the primary ligamentous structures that provide stability. Revisions can be performed with nonconstrained cruciate-retaining, posterior cruciate substituting, or anterior-stabilized/ultracongruent inserts when there are symmetrical flexion/extension gaps and intact collateral ligaments. When the collateral ligaments are insufficient either due to attenuation or incompetence from bone loss, a more constrained knee system is needed. Constrained condylar knees provide increased stability to both varus/valgus and rotation forces with a nonlinked construct. This increased constraint, however, does lead to increased stress at the implant-bone interface which requires more robust metaphyseal fixation. In cases of significant soft tissue disruption, severe flexion/extension gap mismatch or extensor mechanism disruption, a rotating hinge knee is needed to restore stability. Advances in revision implant design have led to improved outcomes and longer survivorship then earlier iterations of these implants. Surgeons should always strive to use the least constraint needed to achieve stability but must have a low threshold to increase constraint when ligament integrity is compromised., Competing Interests: None declared., (Thieme. All rights reserved.)

The direct anterior approach (DAA) is gaining popularity in primary total hip arthroplasty (THA). Although DAA has demonstrated many advantages over other surgical approaches, periprosthetic femur fractures (PPFF) rates continue to be higher. Femoral stem designs that allow for easier insertion via a DAA may contribute to the higher rates of fracture seen in this approach. Certain stem designs and fixation methods may reduce the risk of PPFF via a DAA in primary THA., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Prostaglandin E2 (PGE2) is a bioactive signalling molecule metabolized from the phospholipid membranes by the enzymatic activity of cycloxygenase-2 (COX-2). In the developing brain, COX-2 constitutively regulates the production of PGE2, which is important in neuronal development. However, abnormal COX-2/PGE2 signalling has been linked to neurodevelopmental disorders including autism spectrum disorders (ASDs). We have previously demonstrated that COX-2 - -KI mice show autism-related behaviours including social deficits, repetitive behaviours and anxious behaviours. COX-2-deficient mice also have deficits in pathways involved in synaptic transmission and dendritic spine formation. In this study, we use a Golgi-COX staining method to examine sex-dependent differences in dendritic and dendritic spine morphology in neurons of COX-2 - -KI mice cerebellum compared with wild-type (WT) matched controls at postnatal day 25 (P25). We show that COX-2 - -KI mice have increased dendritic arborization closer to the cell soma and increased dendritic looping. We also observed a sex-dependent effect of the COX-2 - -KI on dendritic thickness, dendritic spine density, dendritic spine morphology, and the expression of β-actin and the actin-binding protein spinophilin. Our findings show that changes in COX-2/PGE2 signalling lead to impaired morphology of dendrites and dendritic spines in a sex-dependant manner and may contribute the pathology of the cerebellum seen in individuals with ASD. This study provides further evidence that the COX-2 - -KI mouse model can be used to study a subset of ASD pathologies., (© 2021 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Background: The purpose of this study is to evaluate survivorship and outcomes of high-activity patients compared to low-activity patients after total hip arthroplasty., Methods: A retrospective review identified 2002 patients (2532 hip) that underwent a primary total hip arthroplasty with vitamin E-infused highly crosslinked polyethylene liner. Patients were divided into 2 groups based on their University of California Los Angeles (UCLA) activity level: low activity (LA) (UCLA ≤5) and high activity (HA) (UCLA ≥6). Outcomes included Harris Hip Score, UCLA activity score, and reoperations. A multivariate nominal regression analysis was performed to evaluate the significance of postoperative activity level on survivorship., Results: The mean follow-up duration was 4.5 years (range, 0.3 to 9.9 years). HA group had significantly higher improvements in Harris Hip Score (HHS) ( P < .001) and UCLA activity score ( P < .001). Aseptic revisions were performed in 2.1% of the LA group and in 0.4% hips of the HA group ( P < .001). After controlling for age, gender, preoperative pain, HHS, and body mass index, a higher postoperative activity level remained a significant factor for improved aseptic survivorship with an odds ratio of 4.9 (95% confidence interval, 1.1 to 21.2, P  = .03). The all-cause 5-year survivorship was 99% for the HA group and 96% to for the LA group ( P < .001). The aseptic 5-year survivorship was 99.6% for the HA group and 98% for the LA group ( P < .001)., Conclusions: This study found that a higher activity level after primary THA was not deleterious to survivorship at short to midterm follow-up with modern implants., (© 2021 The Authors.)

Aims: The purpose of this study is to evaluate early outcomes with the use of a smartphone-based exercise and educational care management system after total hip arthroplasty (THA) and demonstrate decreased use of in-person physiotherapy (PT)., Methods: A multicentre, prospective randomized controlled trial was conducted to evaluate a smartphone-based care platform for primary THA. Patients randomized to the control group (198) received the institution's standard of care. Those randomized to the treatment group (167) were provided with a smartwatch and smartphone application. PT use, THA complications, readmissions, emergency department/urgent care visits, and physician office visits were evaluated. Outcome scores include the Hip disability and Osteoarthritis Outcome Score (HOOS, JR), health-related quality-of-life EuroQol five-dimension five-level score (EQ-5D-5L), single leg stance (SLS) test, and the Timed Up and Go (TUG) test., Results: The control group was significantly younger by a mean 3.0 years (SD 9.8 for control, 10.4 for treatment group; p = 0.007), but there were no significant differences between groups in BMI, sex, or preoperative diagnosis. Postoperative PT use was significantly lower in the treatment group (34%) than in the control group (55.4%; p = 0.001). There were no statistically significant differences in complications, readmissions, or outpatient visits. The 90-day outcomes showed no significant differences in mean hip flexion between controls (101° (SD 10.8)) and treatment (100° (SD 11.3); p = 0.507) groups. The HOOS, JR scores were not significantly different between control group (73 points (SD 13.8)) and treatment group (73.6 points (SD 13); p = 0.660). Mean 30-day SLS time was 22.9 seconds (SD 19.8) in the control group and 20.7 seconds (SD 19.5) in the treatment group (p = 0.342). Mean TUG time was 11.8 seconds (SD 5.1) for the control group and 11.9 (SD 5) seconds for the treatment group (p = 0.859)., Conclusion: The use of the smartphone care management system demonstrated similar early outcomes to those achieved using traditional care models, along with a significant decrease in PT use. Noninferiority was demonstrated with regard to complications, readmissions, and ED and urgent care visits. This technology allows patients to rehabilitate on a more flexible schedule and avoid unnecessary healthcare visits, as well as potentially reducing overall healthcare costs. Cite this article: Bone Joint J  2021;103-B(7 Supple B):91-97.

Background: The thickness of the polyethylene bearing in medial unicondylar knee arthroplasty (UKA) is determined by the depth of the tibial resection, degree of correctable deformity, and balance of the knee. The purpose of this study is to evaluate whether polyethylene thickness in medial mobile-bearing UKA impacts clinical outcomes and survivorship., Methods: A retrospective review from 2004 to 2017 identified patients who underwent a primary mobile-bearing medial UKA with 2-year minimum follow-up or revision. A total of 2305 patients (3030 knees) met inclusion criteria. Patients were divided in 2 groups: thin bearing (group 1): 3-mm or 4-mm bearing and thick bearing (group 2): ≥ 5 mm. The thin group consisted of 2640 knees (87%), whereas the thick group had 390 knees (13%). Preoperative and postoperative demographics, range of motion, Knee Society scores, complications, and reoperations were evaluated., Results: Mean follow-up was 5.2 years (range, 0.5 to 12.6). There was no significant difference between groups in postoperative range of motion or Knee Society scores (P > .05). Manipulations were performed in 1.3% of patients and not significantly different between groups. The all-cause revision rate for group 1 was 4.02% and group 2 was 4.58% (P = .6). Revision rates for tibial aseptic loosening were significantly higher in group 2 (1.8%) than those in group 1 (0.7%) (P = .04). There was no significant difference in failure rates between groups for tibial collapse or fracture, femoral aseptic loosening, arthritic progression, bearing dislocation, or other cause of revision., Conclusion: This study demonstrated that thicker bearings in medial UKA increased the risk of tibial aseptic loosening, but not all-cause failures or clinical outcomes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aims: A limited number of investigations with conflicting results have described perivascular lymphocytic infiltration (PVLI) in the setting of total knee arthroplasty (TKA). The purpose of this study was to determine if PVLI found in TKAs at the time of aseptic revision surgery was associated with worse clinical outcomes and survivorship., Methods: A retrospective review was conducted on 617 patients who underwent aseptic TKA revision who had histological analysis for PVLI at the time of surgery. Clinical and radiological data were obtained pre- and postoperatively, six weeks postoperatively, and then every year thereafter., Results: Within this cohort, 118 patients (19.1%) were found to have PVLI on histological analysis. Re-revision was performed on 83 patients (13.4%) with no significant differences in all-cause or aseptic revisions between groups. A higher incidence of PVLI was noted in female patients (p = 0.037). There was no significant difference in improvement in the range of motion (p = 0.536), or improvement of KSC (p = 0.66), KSP (p = 0.61), or KSF (p = 0.3) clinical outcome scores between PVLI and no PVLI sub-groups. There was a higher incidence of a preoperative diagnosis of pain in the PVLI group compared with patients without PVLI (p = 0.002) present., Conclusion: PVLI found on large-scale histological analysis in TKAs at aseptic revision surgery was not associated with worse clinical outcomes or rates of re-revision. Cite this article: Bone Joint J  2021;103-B(6 Supple A):145-149.

The literature is mixed on the long-term fate of knees that undergo manipulation under anesthesia (MUA). The purpose of this study is to evaluate the long-term outcomes and survivorship of patients who required a MUA after primary total knee arthroplasty (TKA) compared with a cohort of patients who did not undergo a MUA. Between 2003 and 2007, 2,193 patients (2,783 knees) underwent primary TKA with 2-year minimum follow-up; 182 knees (6.5%) had a MUA. Patients who had a manipulation were younger ( p  < 0.001) and had worse preoperative range of motion (ROM) ( p  < 0.001). Postoperative ROM, Knee Society clinical (KSC), functional, and pain (KSP) scores, revisions, and survivorship were compared between MUA and no MUA. Mean follow-up was 9.7 years. MUA patients had lower postoperative ROM ( p  < 0.001), change in ROM ( p  < 0.001), KSC ( p  < 0.001), KSP ( p  < 0.001), and change in KSP scores (0.013). Revisions occurred in 18 knees (9.9%) in the MUA group compared with 77 knees (3%) without a MUA ( p  < 0.001). Most common reason for revision after MUA was continued stiffness (50%). Relative risk for revision after one MUA was 2.01 (95% confidence interval [CI], 1.1-3.8, p  < 0.001) and after three or more MUAs were 27.02 (95% CI, 16.5-44.1, p  < 0.001). Ten-year survival after MUA was 89.4% (95% CI, 87.1-91.7%) compared with 97.2% (95% CI, 96.9-97.5%) without a MUA ( p  < 0.001). Patients who undergo a MUA after primary TKA may have a knee at risk with higher revision rates, worse long-term clinical scores, ROM and survivorship., Competing Interests: None declared., (Thieme. All rights reserved.)

Aims: The purpose is to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model., Methods: A multicentre prospective randomized controlled trial was conducted evaluating the use of a smartphone-based care management system for primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA). Patients in the control group (n = 244) received the respective institution's standard of care with formal physiotherapy. The treatment group (n = 208) were provided a smartwatch and smartphone application. Early outcomes assessed included 90-day knee range of movement, EuroQoL five-dimension five-level score, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score, 30-day single leg stance (SLS) time, Time up and Go (TUG) time, and need for manipulation under anaesthesia (MUA)., Results: Overall, 90-day mean flexion was not significantly different between the control (121° (SD 11.7°)) and treatment groups (121 o ; p = 0.559); 90-day mean SLS was 22.7 seconds (SD 9.8) in controls and 24.3 seconds (SD 20.8) in treatment (p = 0.519); 90-day mean TUG times were 10.1 seconds (SD 4.8) in control and 9.3 seconds (SD 3.3) in treatment (p = 0.139). Mean KOOS JR scores were significantly different between control group (73.6 (SD 13.4)) and treatment group (70.4 (SD 12.6); p = 0.026). MUAs were performed in nine (3.7%) patients in the control group and four (1.9%) in the treatment group (p = 0.398). Physiotherapy was performed by 230 (94.4%) of control group and 123 (59.3%) of treatment group (p < 0.001). There were no significant differences between groups in postoperative urgent care visits, or readmissions within 90 days, with significantly fewer emergency department visits in the treatment group (16 (8.2%) vs five (2.5%), p = 0.014)., Conclusion: The use of the smartwatch/smartphone care platform demonstrated non-inferiority of clinically significant outcomes to traditional care models, while requiring significantly less postoperative physiotherapy and fewer emergency department visits. This platform could aid in decreasing postoperative costs, while improving patient engagement and communication with the healthcare team. Cite this article: Bone Joint J  2021;103-B(6 Supple A):3-12.