Pool-Based Surfboard Elicits Activation of Posterior Shoulder Muscles During a Surfing Stroke.

ABSTRACT: Pexa, BS, Johnston, CD, Elder, EE, Ford, KR, Patterson, MQ, and Myers, JB. Pool-based surfboard elicits activation of posterior shoulder muscles during a surfing stroke. J Strength Cond Res 38(7): 1300-1304, 2024-Surfboard paddling may activate posterior shoulder muscles, which are critical to baseball pitchers' injury risk and performance. The purpose of this study was to measure posterior shoulder muscle activation during different phases of the surf stroke (propulsion vs. recovery) on a pool-based surfboard. Twenty healthy active adult subjects completed a familiarization and testing session with the pool-based surfboard. During the testing session, electromyography (EMG) sensors were placed on 6 posterior shoulder muscles: latissimus dorsi, infraspinatus, posterior deltoid, upper trapezius, middle trapezius, and lower trapezius. Subjects completed 4 laps in a pool at 3 separate resistances (low, moderate, and heavy) in a randomized order. The peak EMG signal during each phase (propulsion and recovery) was recorded. A 2-way within subject ANOVA (resistance-by-phase) with post hoc Bonferroni's corrections was used to identify differences in EMG activation. There was a significant main effect of phase for the latissimus dorsi (F = 91.3, p < 0.001), upper trapezius (F = 36.5, p < 0.001), middle trapezius (F = 33.8, p < 0.001), and lower trapezius (F = 21.6, p < 0.001). The latissimus dorsi demonstrated higher activation during the propulsion phase (p < 0.001), and all trapezius muscles demonstrated higher activation during the recovery phase (p < 0.001). There was a significant main effect of resistance for the posterior deltoid (F = 3.4, p = 0.043), with higher muscle activation in the low resistance trials compared with the heavy resistance trials (p = 0.036). Recreationally active individuals demonstrate activation of the posterior shoulder when using a pool-based surfboard. This pool-based surfboard may be beneficial to activate the posterior musculature and may be more accessible than standard surfing to baseball athletes.

Stepping up with GGIR: Validity of step cadence derived from wrist-worn research-grade accelerometers using the verisense step count algorithm.

The Verisense Step Count Algorithm facilitates generation of steps from wrist-worn accelerometers. Based on preliminary evidence suggesting a proportional bias with overestimation at low steps/day, but underestimation at high steps/day, the algorithm parameters have been revised. We aimed to establish validity of the original and revised algorithms relative to waist-worn ActiGraph step cadence. We also assessed whether step cadence was similar across accelerometer brand and wrist. Ninety-eight participants (age: 58.6±11.1 y) undertook six walks (~500 m hard path) at different speeds (cadence: 92.9±9.5-127.9±8.7 steps/min) while wearing three accelerometers on each wrist (Axivity, GENEActiv, ActiGraph) and an ActiGraph on the waist. Of these, 24 participants also undertook one run (~1000 m). Mean bias for the original algorithm was -21 to -26.1 steps/min (95% limits of agreement (LoA) ~±65 steps/min) and mean absolute percentage error (MAPE) 17-22%. This was unevenly distributed with increasing error as speed increased. Mean bias and 95%LoA were halved with the revised algorithm parameters (~-10 to -12 steps/min, 95%LoA ~30 steps/min, MAPE ~10-12%). Performance was similar across brand and wrist. The revised step algorithm provides a more valid measure of step cadence than the original, with MAPE similar to recently reported wrist-wear summary MAPE (7-11%).

Stepping towards More Intuitive Physical Activity Metrics with Wrist-Worn Accelerometry: Validity of an Open-Source Step-Count Algorithm.

Stepping-based targets such as the number of steps per day provide an intuitive and commonly used method of prescribing and self-monitoring physical activity goals. Physical activity surveillance is increasingly being obtained from wrist-worn accelerometers. However, the ability to derive stepping-based metrics from this wear location still lacks validation and open-source methods. This study aimed to assess the concurrent validity of two versions (1. original and 2. optimized) of the Verisense step-count algorithm at estimating step-counts from wrist-worn accelerometry, compared with steps from the thigh-worn activPAL as the comparator. Participants (n = 713), across three datasets, had >24 h continuous concurrent accelerometry wear on the non-dominant wrist and thigh. Compared with activPAL, total daily steps were overestimated by 913 ± 141 (mean bias ± 95% limits of agreement) and 742 ± 150 steps/day with Verisense algorithms 1 and 2, respectively, but moderate-to-vigorous physical activity (MVPA) steps were underestimated by 2207 ± 145 and 1204 ± 103 steps/day in Verisense algorithms 1 and 2, respectively. In summary, the optimized Verisense algorithm was more accurate in detecting total and MVPA steps. Findings highlight the importance of assessing algorithm performance beyond total step count, as not all steps are equal. The optimized Verisense open-source algorithm presents acceptable accuracy for derivation of stepping-based metrics from wrist-worn accelerometry.

The Effect of the IPACK Block on Pain After Primary TKA: A Double-Blinded, Prospective, Randomized Trial.

BACKGROUND: The purpose of this study was to determine if infiltration of local anesthetic between the interspace between the popliteal artery and capsule of the knee (IPACK) provides benefit in total knee arthroplasty. METHODS: Patients were randomized into continuous adductor canal block with IPACK block or continuous adductor canal block with sham subcutaneous saline injection. Only the anesthesiologist performing the block was aware of randomization status. After surgery, a blinded assessor recorded opioid consumption, pain scores, and gait distance. RESULTS: There were 35 patients in the IPACK group and 34 in the NO IPACK group. There was no difference demographically between the groups. In the postanesthesia care unit (PACU), the average (P = .0122) and worst (P = .0168) pain scores at rest were statistically lower in the IPACK group. There was no difference in the pain scores during physical therapy (P = .2080). There was no difference in opioid consumption in the PACU (P = .7928), or at 24 hours (P = .7456). There was no difference in pain scores on POD 1 in the AM (P = .4597) or PM (P = .6273), or in the walking distance (P = .5197). There was also no difference in length of stay in the PACU (P = .9426) or hospital (P = .2141). CONCLUSION: The IPACK group had lower pain scores at rest in the PACU, but this is likely not clinically significant. The routine use of the IPACK is not supported by the results of this study. There may be indications for the use of the IPACK block as a rescue block or in patients who have contraindications to our standard multimodal treatment regimen or in patients with chronic pain or opioid dependence.

A 30-day prospective audit of all inpatient complications following acute care surgery: How well do we really perform?

Background: Acute care surgery (ACS) and emergency general surgery (EGS) services must provide timely care and intervention for patients who have some of the most challenging needs. Patients treated by ACS services are often critically ill and have both substantial comorbidities and poor physiologic reserve. Despite the widespread implemention of ACS/EGS services across North America, the true postoperative morbidity rates remain largely unknown. Methods: In this prospective study, inpatients at 8 high-volume ACS/EGS centres in geographically diverse locations in Canada who underwent operative interventions were followed for 30 days or until they were discharged. Readmissions during the 30-day window were also captured. Preoperative, intraoperative and postoperative variables were tracked. Standard statistical methodology was employed. Results: A total of 601 ACS/EGS patients were followed for up to 30 inpatient or readmission days after their index emergent operation. Fifty-one percent of patients were female, and the median age was 51 years. They frequently had substantial medical comorbidities (42%) and morbid obesity (15%). The majority of procedures were minimally invasive (66% laparoscopic). Median length of stay was 3.3 days and the early readmission (< 30 d) rate was 6%. Six percent of patients were admitted to the critical care unit. The overall complication and mortality rates were 34% and 2%, respectively. Cholecystitis (31%), appendicitis (21%), bowel obstruction (18%), incarcerated hernia (12%), gastrointestinal hemorrhage (7%) and soft tissue infections (7%) were the most common diagnoses. The morbidity and mortality rates for open surgical procedures were 73% and 5%, respectively. Conclusion: Nontrauma ACS/EGS procedures are associated with a high postoperative morbidity rate. This study will serve as a prospective benchmark for postoperative complications among ACS/EGS patients and subsequent quality improvement across Canada.

Contexte: Les services de chirurgie dans les unités de soins actifs (CSA) et de chirurgie générale dans les services d'urgence (CGSU) doivent fournir rapidement des soins et des interventions à des patients dont les besoins sont parmi les plus complexes. En effet, les patients pris en charge par les services de CSA sont souvent gravement malades et présentent des comorbidités sur fond de faible réserve physiologique. Même si les services de CSA/CGSU se sont répandus en Amérique du Nord, les taux réels de morbidité postopératoire demeurent pour une bonne part inconnus. Méthodes: Dans cette étude prospective, on a suivi pendant 30 jours ou jusqu'à leur congé, les patients hospitalisés pour des interventions chirurgicales dans 8 centres de CSA/CGSU achalandés de divers endroits au Canada. On a également tenu compte des réadmissions dans les 30 jours. Les paramètres pré-, per- et postopératoires ont été enregistrés. Une méthodologie statistique standard a été appliquée. Résultats: En tout, 601 patients de CSA/CGSU ont ainsi été suivis pendant une durée allant jusqu'à 30 jours d'hospitalisation ou de réadmission après leur intervention urgente initiale. Cinquante et un pour cent étaient de sexe féminin et l'âge moyen était de 51 ans. Ces patients étaient nombreux à présenter des comorbidités de nature médicale substantielles (42 %) et une obésité morbide (15 %). La majorité des interventions ont été minimalement effractives (66 % laparoscopiques). La durée médiane des séjours a été de 3,3 jours et le taux de réadmission précoce (< 30 j) a été de 6 %. Six pour cent des patients ont été admis aux soins intensifs. Les taux globaux de complications et de mortalité ont été respectivement de 34 % et de 2 %. Cholécystite (31 %), appendicite (21 %), obstruction intestinale (18 %), hernie incarcérée (12 %), hémorragie digestive (7 %) et infections des tissus mous (7 %) comptent parmi les diagnostics les plus fréquents. Les taux de morbidité et de mortalité dans les cas de chirurgies ouvertes ont été respectivement de 73 % et 5 %. Conclusion: Les interventions de CSA/CGSU non liées à la traumatologie sont associées à un taux de morbidité postopératoire élevé. Cette étude fournira un ensemble de valeurs de références pour l'étude prospective des complications chez les patients pris en charge par les services de CSA/CGSU et l'amélioration subséquente des soins partout au Canada.

Vibrational and Structural Studies of Environmentally Persistent Free Radicals Formed by Phenol-Dosed Metal Oxide Nanoparticles.

Environmentally persistent free radicals (EPFRs) are formed by the adsorption of substituted aromatic precursors on the surface of metal oxides and are known to have significant health and environmental impact due to their unique stability. In this article, the formation of EPFRs is studied by adsorption of phenol on ZnO, CuO, Fe2O3, and TiO2 nanoparticles (∼10-50 nm) at high temperatures. Electron paramagnetic resonance indicates the formation of phenoxyl-type radicals. Fourier transform infrared spectroscopy provides further evidence of EPFR formation by the disappearance of -OH groups, indicating the chemisorption of the organic precursor on the metal oxide surface. These results are further confirmed by inelastic neutron scattering, which shows both ring out-of-plane bend and C-H in-plane bend motions characteristic of phenol adsorption on the studied systems. Also, the changes in the oxidation state of the metal cations are investigated by X-ray photoelectron spectroscopy, which shows that the direction of electron transfer (redox) during phenol chemisorption is strongly dependent on surface properties as well as surface defects of the metal oxide surface.

Biophysical characterization of monofilm model systems composed of selected tear film phospholipids.

The tear film protects the eye from foreign particles and pathogens, prevents excess evaporation, provides lubrication, and maintains a high quality optical surface necessary for vision. The anterior layer of tear film consists of polar and non-polar lipid layers. The polar lipids form a monolayer on the aqueous subphase, acting as surfactants for the non-polar lipid multilayer. A tear film polar lipid biomimetic consisting of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylethanolamine (DPPE), palmitoyl glucosylceramide (PGC), and palmitoyl sphingomyelin (PSM) was characterized using Langmuir monolayers and Brewster angle microscopy (BAM). Lipid combinations formed very stable monolayers, especially those containing DPPC or PSM. Surface experiments and elasticity analyses revealed that PGC resulted in more condensed and rigid mixed monolayers. DPPE provided resistance to large changes in lipid ordering over a wide surface pressure range. Ternary mixtures containing DPPE and PGC with either DPPC or PSM experienced the greatest lipid ordering within the natural tear film surface pressure range suggesting that these lipids are important to maintain tear film integrity during the inter-blink period. Finally, BAM images revealed unique structures within monolayers of DPPC, DPPE, and PGC at the natural tear film surface pressure. 3D analysis of these domains suggested either the formation of multilayers or outward protrusions at surface pressures far below the point of irreversible collapse as seen on the isotherm. This entails that the polar lipids of tear film may be capable of multilayer formation or outward folding as a mechanism to prevent rupture of the tear film during a blink.

The effect of repeated lateral compression and expansions mimicking blinking on selected tear film polar lipid monofilms.

The tear film lipid layer is formed on the anterior surface of the eye, functioning as a barrier to excess evaporation and foreign particles, while also providing stability to the tear film. The lipid layer is organized into a polar lipid layer consisting of phospholipids, ceramides, and free fatty acids that act as a surfactant to a non-polar multilayer of wax and cholesterol esters. Due to shear forces from eye movement and the compression and expansion of blinking, the tear lipids are under constant stress. However, tear film is able to resist immediate rupture and remains intact over multiple blinks. This work aimed to better understand the lateral organization of selected tear film polar lipids. The polar lipid biomimetic studied here consisted of dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylethanolamine (DPPE), palmitoyl glucosylceramide (PGC), and palmitoyl sphingomyelin (PSM). Surface pressure-area isocycles mimicked blinking and films were visualized by Brewster angle microscopy (BAM). All lipid systems formed relatively reversible films as indicated by limited hysteresis. However, pure DPPC and PSM films experienced greater changes in lipid packing upon compression and expansion compared to pure PGC and DPPE. This suggests that the driving force behind maintaining the lateral organization of the polar lipids from tear film may be the hydrogen bonding propensities of the head groups. Additionally, isocycles of films containing DPPC, DPPE, and PGC mixtures exhibited evidence for reversible multilayer formation or folding. This was supported by 3D analysis of structures that formed during compression but reintegrated back into the bulk lipid film during expansion near the in vitro tear film surface pressure of the open eye. Therefore, the polar lipids of tear film may be directly involved in preventing film rupture during a blink.

Formation of environmentally persistent free radicals (EPFRs) on ZnO at room temperature: Implications for the fundamental model of EPFR generation.

Environmentally persistent free radicals (EPFRs) have significant environmental and public health impacts. In this study, we demonstrate that EPFRs formed on ZnO nanoparticles provide two significant surprises. First, EPR spectroscopy shows that phenoxy radicals form readily on ZnO nanoparticles at room temperature, yielding EPR signals similar to those previously measured after 250°C exposures. Vibrational spectroscopy supports the conclusion that phenoxy-derived species chemisorb to ZnO nanoparticles under both exposure temperatures. Second, DFT calculations indicate that electrons are transferred from ZnO to the adsorbed organic (oxidizing the Zn), the opposite direction proposed by previous descriptions of EPFR formation on metal oxides.

Ultrasound-guided popliteal sciatic nerve blockade in the severely and morbidly obese: a prospective and randomized study.

PURPOSE: Limited research data exist regarding optimal block techniques in the severely and morbidly obese patient population. We compared two approaches to sciatic nerve blockade at the popliteal fossa in severely and morbidly obese patients. The purpose of this study was to identify differences in pain scores, block onset characteristics, and adverse events between the proximal (prebifurcation) and the distal (postbifurcation) sites. METHODS: Patients with a body mass index ≥35 scheduled for unilateral foot surgery with a popliteal block were randomized to receive an ultrasound-guided popliteal block proximal or distal to the bifurcation of the sciatic nerve. The primary endpoint was numerical rating scale (NRS) scores in the post anesthesia care unit (PACU). RESULTS: Thirty patients were enrolled in each group for a total of 60 participants. Patients in the distal group had lower NRS scores upon entry into the PACU (0.70 ± 1.91) compared with the proximal group (2.17 ± 3.37), had a faster onset of sensorimotor blockade, and were less likely to require a repeat block procedure, conversion to general anesthesia, or local anesthetic supplementation by the surgical team. There was no difference in block procedure times or incidence of nerve injury between the two groups. CONCLUSIONS: The distal approach to the popliteal block provided several intraoperative and analgesic benefits without a difference in block procedural times in the severely and morbidly obese. It is a cost-free intervention that results in a higher likelihood of a successful block in a population where avoidance of opioids is desirable.

Electronic signatures of a model pollutant-particle system: chemisorbed phenol on TiO2(110).

Environmentally persistent free radicals (EPFRs) are a class of composite organic/metal oxide pollutants that have recently been discovered to form from a wide variety of substituted benzenes chemisorbed to commonly encountered oxides. Although a qualitative understanding of EPFR formation on particulate metal oxides has been achieved, a detailed understanding of the charge transfer mechanism that must accompany the creation of an unpaired radical electron is lacking. In this study, we perform photoelectron spectroscopy and electron energy loss spectroscopy on a well-defined model system-phenol chemisorbed on TiO2(110) to directly observe changes in the electronic structure of the oxide and chemisorbed phenol as a function of adsorption temperature. We show strong evidence that, upon exposure at high temperature, empty states in the TiO2 are filled and the phenol HOMO is depopulated, as has been proposed in a conceptual model of EPFR formation. This experimental evidence of charge transfer provides a deeper understanding of the EPFR formation mechanism to guide future experimental and computational studies as well as potential environmental remediation strategies.

Probing environmentally significant surface radicals: Crystallographic and temperature dependent adsorption of phenol on ZnO.

Environmentally persistent free radicals (EPFRs) are toxic organic/metal oxide composite particles that have been discovered to form from substituted benzenes chemisorbed to metal oxides. Here, we perform photoelectron spectroscopy, electron energy loss spectroscopy, and low energy electron diffraction of phenol chemisorbed to ZnO(1 0 1̱ 0) and (0 0 0 1̱)-Zn to observe electronic structure changes and charge transfer as a function adsorption temperature. We show direct evidence of charge transfer from the ZnO surfaces to the phenol. This evidence can help gain a better understanding of EPFRs and be used to develop possible future remediation strategies.

An ambulatory method of identifying anterior cruciate ligament reconstructed gait patterns.

The use of inertial sensors to characterize pathological gait has traditionally been based on the calculation of temporal and spatial gait variables from inertial sensor data. This approach has proved successful in the identification of gait deviations in populations where substantial differences from normal gait patterns exist; such as in Parkinsonian gait. However, it is not currently clear if this approach could identify more subtle gait deviations, such as those associated with musculoskeletal injury. This study investigates whether additional analysis of inertial sensor data, based on quantification of gyroscope features of interest, would provide further discriminant capability in this regard. The tested cohort consisted of a group of anterior cruciate ligament reconstructed (ACL-R) females and a group of non-injured female controls, each performed ten walking trials. Gait performance was measured simultaneously using inertial sensors and an optoelectronic marker based system. The ACL-R group displayed kinematic and kinetic deviations from the control group, but no temporal or spatial deviations. This study demonstrates that quantification of gyroscope features can successfully identify changes associated with ACL-R gait, which was not possible using spatial or temporal variables. This finding may also have a role in other clinical applications where small gait deviations exist.

EPFR Formation from Phenol adsorption on Al2O3 and TiO2: EPR and EELS studies.

We have examined the formation of environmentally persistent free radicals (EPFRs) from phenol over alumina and titania using both powder and single-crystal samples. Electron paramagnetic resonance (EPR) studies of phenol adsorbed on metal oxide powders indicates radical formation on both titania and alumina, with both oxides forming one faster-decaying species (lifetime on the order of 50-100 hours) and one slower-decayng species (lifetimes on the order of 1000 hours or more). Electron energy loss spectroscopy (EELS) measurements comparing physisorbed phenol on single-crystal TiO2(110) to phenoxyl radicals on the same substrate indicate distinct changes in the π-π* transitions from phenol after radical formation. The identical shifts are observed from EELS studies of phenoxyl radicals on ultrathin alumina grown on NiAl(110), indicating that this shift in the π-π* transition may be taken as a general hallmark of phenoxyl radical formation.

40 years of actigraphy in sleep medicine and current state of the art algorithms.

For the last 40 years, actigraphy or wearable accelerometry has provided an objective, low-burden and ecologically valid approach to assess real-world sleep and circadian patterns, contributing valuable data to epidemiological and clinical insights on sleep and sleep disorders. The proper use of wearable technology in sleep research requires validated algorithms that can derive sleep outcomes from the sensor data. Since the publication of the first automated scoring algorithm by Webster in 1982, a variety of sleep algorithms have been developed and contributed to sleep research, including many recent ones that leverage machine learning and / or deep learning approaches. However, it remains unclear how these algorithms compare to each other on the same data set and if these modern data science approaches improve the analytical validity of sleep outcomes based on wrist-worn acceleration data. This work provides a systematic evaluation across 8 state-of-the-art sleep algorithms on a common sleep data set with polysomnography (PSG) as ground truth. Despite the inclusion of recently published complex algorithms, simple regression-based and heuristic algorithms demonstrated slightly superior performance in sleep-wake classification and sleep outcome estimation. The performance of complex machine learning and deep learning models seem to suffer from poor generalization. This independent and systematic analytical validation of sleep algorithms provides key evidence on the use of wearable digital health technologies for sleep research and care.

Fang shape varies with ontogeny and sex in the venomous elapid snake Pseudonaja affinis.

A predator's preferred prey often changes over the course of its life as it grows from an inexperienced juvenile through to a sexually mature adult. For species with highly specialised feeding strategies, this may require its anatomy to change over the course of its life. The dugite (Pseudonaja affinis, Günther 1872) is a venomous snake from Australia that displays such a diet shift, with juveniles feeding on small reptiles, while adults mainly target mammals. We examined the morphology of fangs across both sexes and throughout ontogeny using geometric morphometrics and cross-sectional sharpness measurements of key functional regions on these teeth. This highlighted key differences in shape that likely relate to the varied properties of their adult and juvenile diet. We found that juveniles display a more robust and blunter fang, which likely relates to feeding on scaly lizard prey, whereas adults have slender fangs with sharper tips, which reflects their diet of softer mammalian prey. There were also differences between males and females, with male snakes having significantly more slender fangs than females, which might be an indication of niche partitioning between the sexes. Using snout-vent length as a proxy for age, we found that the ontogenetic shift in fang shape occurs when P. affinis is around 60 cm long, corresponding with previous studies that found this size to be the moment where these snakes switch from their juvenile to adult diet.

Chlamydophila pneumoniae infection among Basic Underwater Demolition/SEAL (BUD/S) candidates, Coronado, California, July 2008.

Community-acquired pneumonia can compromise readiness of recruits and service members operating in confined spaces. Often respiratory pathogens are implicated in outbreaks. In July 2008, 5 Basic Underwater Demolition/SEAL students entering an intense period of training at Naval Amphibious Base Coronado reported with clinical symptoms and chest radiographs consistent with pneumonia. Throat and nasal swabs were tested for respiratory pathogens. Molecular evidence indicated that they were infected with the atypical bacterium Chlamydophila pneumoniae. Thirty contemporaneous Basic Underwater Demolition/SEAL students were tested to determine the extent of C pneumoniae infection burden. Five additional cases were captured within this group. The 10 individuals diagnosed with C pneumoniae were treated with a course of azithromycin, Avelox (moxifloxacin hydrochloride), and doxycycline. The cases ended following the isolation of cases and prophylaxis with oral antibiotics. This work highlights the importance of rapid respiratory disease diagnoses to guide the clinical response following the emergence of respiratory infections among military trainees.

Myeloid Sarcoma Presenting as Obstructive Jaundice.

Myeloid sarcoma (MS) is a rare solid neoplasm that consists of extramedullary myeloid precursor cells. Generally, it is associated with underlying acute myeloid leukemia (AML) or AML yet to manifest clinically. It can present as isolated, also known as primary MS without evidence of AML or other myeloproliferative neoplasms. We present the case of a previously healthy 36-year-old male, who was admitted to hospital with new-onset painful obstructive jaundice and final diagnosis of isolated MS was made after through investigations. We are pleased to report that he had favorable response to the treatment and remains well.

Perioperative population management for primary hip arthroplasty reduces hospital and postacute care utilization while maintaining or improving care quality.

STUDY OBJECTIVE: Physician-led multidisciplinary care coordination decreases hospital-associated care needs. We aimed to determine whether such care coordination can show benefits through the posthospital discharge period for elective hip surgery. DESIGN: Time Series of prospectively recorded and historical data. SETTING: Academic tertiary care medical center and health system. PATIENTS: 449 patients undergoing elective primary hip surgery. INTERVENTIONS: For the intervention group we redesigned care with a comprehensive 14-16 week multidisciplinary standardized clinical pathway, the Ochsner hip arthroplasty perioperative surgical home (PSH). Essential pathway components were preoperative medical risk assessment, frailty scoring, home assessment, education and expectation setting. Collaborative team-based care, rigorous application of perioperative milestones, and proactive postoperative care coordination were key elements. MEASUREMENTS: The intervention group was compared to historical controls with regard to demographics, risk factors, quality metrics, resource utilization and discharge disposition, the primary outcomes were hospital length of stay and postacute facility utilization. MAIN RESULTS: Compared to historical controls, the intervention group had similar risk factors and the same or better quality outcomes. It had less combined skilled nursing facility (SNF) and inpatient rehabilitation facility (IRF) utilization compared to controls (16.5% vs. 27.5%). More intervention patients were discharged with home self-care compared to historical controls (10.7% vs 5.3%). During the intervention period combined SNF/IRF utilization decreased substantially from 19.8% early on, to 13.2% during a later phase. Intervention patients had fewer hospital days compared to historical controls (1.86 vs 3.34 days, respectively; P < 0.0001). CONCLUSIONS: A perioperative population management oriented care model redesign was effective in decreasing hospital days and postacute facility-based care utilization, while quality metrics were maintained or improved.