Changes in the composition of invertebrate assemblages from wave-exposed intertidal mussel stands along the Nova Scotia coast, Canada.

Rocky intertidal habitats occur worldwide and are mainly characterized by primary space holders such as seaweeds and sessile invertebrates. Some of these organisms are foundation species, as they can form structurally complex stands that host many small invertebrates. The abundance of primary space holders is known to vary along coastlines driven directly or indirectly by environmental variation. However, it is less clear if the invertebrate assemblages associated to a foundation species may remain relatively unchanged along coastlines, as similar stands of a foundation species can generate similar microclimates. We examined this question using abundance data for invertebrate species found in mussel stands of a similar structure in wave-exposed rocky habitats at mid-intertidal elevations along the Atlantic coast of Nova Scotia (Canada). While the most abundant invertebrate species were found at three locations spanning 315 km of coastline, species composition (a combined measure of species identity and their relative abundance) differed significantly among the locations. One of the species explaining the highest amount of variation among locations (a barnacle) exhibited potential signs of bottom-up regulation involving pelagic food supply, suggesting benthic-pelagic coupling. The abundance of the species that explained the highest amount of variation (an oligochaete) was positively related to the abundance of their predators (mites), further suggesting bottom-up forcing in these communities. Overall, we conclude that species assemblages associated to structurally similar stands of a foundation species can show clear changes in species composition at a regional scale.

Outcomes of isolated medial tibial plateau fractures by fracture morphology.

PURPOSE: To identify a cohort of isolated medial tibial plateau fractures treated with surgical fixation and to categorize them by Moore and Wahlquist classifications in order to determine the rate of complications with each fracture morphology and the predictive value of each classification system. We hypothesized there would be high rates of neurovascular injury, compartment syndrome, and complications overall with a higher incidence of neurovascular injury in Moore type III rim avulsion fractures and Wahlquist type C fractures that enter the plateau lateral to the tibial spines. METHODS: Patients who presented to six Level I trauma centers between 2010 and 2021 who underwent surgical fixation for isolated medial tibial plateau fractures were retrospectively reviewed. Data including demographics, radiographs, complications, and functional outcomes were collected. RESULTS: One hundred and fifty isolated medial tibial plateau fractures were included. All patients were classified by the Wahlquist classification of medial tibial plateau fractures, and 139 patients were classifiable by the Moore classification of tibial plateau fracture-dislocations. Nine percent of fractures presented with neurovascular injury: 5 % with isolated vascular injury and 6 % with isolated nerve injury. There were no significant differences in neurovascular injury by fracture type (Wahlquist p = 0.16, Moore p = 0.33). Compartment syndrome developed in two patients (1.3 %). The average final range of motion was 0.8-122° with no difference by Wahlquist or Moore classifications (p = 0.11, p = 0.52). The overall complication rate was 32 % without differences by fracture morphology. The overall rate of return to the operating room (OR) was 25 %. CONCLUSIONS: Isolated medial tibial plateau fractures often represent fracture-dislocations of the knee and should receive a meticulous neurovascular exam on presentation with a high suspicion for neurovascular injury. No specific fracture pattern was found to be predictive of neurovascular injuries, complications, or final knee range of motion. Patients should be counseled pre-operatively regarding high rates of return to the OR after the index surgery.

Historic indications for fixation of posterior malleolus fractures- where did they come from and where are we now?

INTRODUCTION: The indications for reduction and fixation of the posterior malleolus component of rotational ankle fractures have been controversial for nearly a century. This study aims to identify the historical basis for surgical intervention and trace trends in management strategies over time. METHODS: In March 2023, a systematic review of full-text, English-language articles providing indications for surgical fixation of the posterior malleolus component of rotational ankle fractures was performed. Articles underwent title and abstract screening before undergoing full-text review. RESULTS: Historical indications for surgical fixation were size-dependent, with fractures comprising 25 % to 33 % of the plafond recommended for internal fixation. Modern studies suggest that nonoperative management of posterior malleolus fractures below this threshold results in residual malreduction of the articular surface, syndesmotic instability, and an increased need for independent fixation of the syndesmosis. CONCLUSIONS: Size-based indications for posterior malleolus fracture fixation are based on Level V evidence from small retrospective case series published nearly one century ago and should be retired. While the size of the posterior malleolus component cannot be ignored, additional factors like fracture morphology and location within the plafond should guide modern surgical indications. Contemporary studies indicate that reduction and fixation of small posterior malleolus fractures (comprising less than 25 % of the articular surface) are associated with improved articular reductions, tibiotalar contact pressures, syndesmotic stability with decreased need for independent fixation of the syndesmosis, and superior postoperative outcomes.

A novel B,O,N-doped mesogen with narrowband MR-TADF emission.

Modification of an unsymmetric B,O,N-doped aromatic core with peripheral mesogenic units triggers self-assembly into a columnar hexagonal mesophase, which is stable between 22 and 144 °C. The columnar assembly is preserved in a glassy state below 22 °C. The B,O,N-doped mesogen displays narrowband sky-blue multiresonance thermally activated delayed fluorescence (MR-TADF) under diluted conditions and bright excimer emission in condensed phase. Our combined experimental and theoretical approach provides insight into the development of strongly aggregating liquid crystalline MR-TADF emitters.

Stem cell-derived vessels-on-chip for cardiovascular disease modeling.

The metabolic syndrome is accompanied by vascular complications. Human in vitro disease models are hence required to better understand vascular dysfunctions and guide clinical therapies. Here, we engineered an open microfluidic vessel-on-chip platform that integrates human pluripotent stem cell-derived endothelial cells (SC-ECs). The open microfluidic design enables seamless integration with state-of-the-art analytical technologies, including single-cell RNA sequencing, proteomics by mass spectrometry, and high-resolution imaging. Beyond previous systems, we report SC-EC maturation by means of barrier formation, arterial toning, and high nitric oxide synthesis levels under gravity-driven flow. Functionally, we corroborate the hallmarks of early-onset atherosclerosis with low sample volumes and cell numbers under flow conditions by determining proteome and secretome changes in SC-ECs stimulated with oxidized low-density lipoprotein and free fatty acids. More broadly, our organ-on-chip platform enables the modeling of patient-specific human endothelial tissue and has the potential to become a general tool for animal-free vascular research.

3D Topographical Scanning for the Detection of Osteoporosis.

Objectives: Osteoporosis is associated with greater risk of fracture, which can lead to increased morbidity and mortality. DEXA scans are often inaccessible for patients, leaving many cases of osteoporosis undetected. A portable 3D topographical scan offers an easily accessible and inexpensive potential adjunct screening tool. We hypothesized that 3D scanning of arm and calf circumference and volume would correlate with DEXA T-scores. Methods: 96 female patients were enrolled. Patients were consented and completed a topographical scan of bilateral arms and lower legs with a mobile 3D scanner for arm and calf circumference and volume in clinic. Patient charts were then retrospectively reviewed for DEXA T-scores. Results: Forearm DEXA T-score was positively correlated with arm circumference (r = 0.49, p<0.01), arm volume (r=0.62, p<0.01), and calf volume (r=0.47, p<0.01). Femoral neck DEXA T-score was positively correlated with calf circumference (r=0.36, p<0.01) and calf volume (r=0.36, p<0.01). Conclusions: Our results showed significant correlations between DEXA T-scores and topographical measurements from mobile device acquired 3D scans, although these were in the "moderate" range. Mobile device-based 3D scanning may hold promise as an adjunct screening tool for osteoporosis when DEXA scanning is not available or feasible for patients, although further studies are needed to elucidate the full potential of its clinical utility. At a minimum, identifying a patient as high risk may promote earlier diagnostic DEXA scanning.

The use of hinged elbow orthosis following surgical management of terrible triad injuries of the elbow.

PURPOSE: To determine outcomes following surgical management of terrible triad injuries in patients treated with and without a hinged elbow orthosis (HEO) in the post-operative setting. METHODS: This study was a retrospective review of 41 patients who underwent surgical treatment of terrible triad injuries including radial head fracture, coronoid fracture, and ulnohumeral dislocation between 2008 and 2023 with at least 10-week follow-up. RESULTS: Nineteen patients were treated post-operatively without HEO, and 22 patients were treated with HEO. There were no differences in range of motion (ROM) between patients treated with and without HEO in final flexion-extension arc (118.4° no HEO, 114.6° HEO, p = 0.59) or pronation-supination arc (147.8° no HEO, 141.4° HEO, p = 0.27). Five patients treated without HEO and one patient treated with HEO returned to the operating room for stiffness (26%, 5%, p = 0.08). QuickDASH scores were similar between groups (p = 0.69). CONCLUSIONS: This study found no difference in post-operative ROM, complications, or QuickDASH scores in patients treated post-operatively with or without HEO. Based on these results, we cannot determine whether the use of HEO adds additional stability to the elbow while initiating ROM exercises post-operatively.

Factors affecting residency selection for underrepresented minorities pursuing orthopaedic surgery.

BACKGROUND: The United States is increasingly diverse and there are many benefits to an equally diverse physician workforce. Despite this, the percentage of under-represented minorities in orthopaedic surgery has remained stagnant. The purpose of this study was to describe the characteristics underrepresented minorities pursuing orthopaedic surgery value most when evaluating residency programs. METHODS: The contact information of current underrepresented minority orthopaedic surgery residents were obtained through professional society databases, residency program coordinators and residency program websites. Individuals were sent a survey through which they evaluated the importance of a variety of program characteristics. RESULTS: The most influential program characteristics were resident happiness and camaraderie, program reputation, geographic location, and relationships between residents and attendings. The least influential characteristics were sub-internship scholarship opportunities for minorities, program affiliation with diversity organizations, word of mouth from others, number of fellows, and centralized training sites. CONCLUSIONS: There is a need to diversify the field of orthopaedic surgery, which begins by selecting more diverse trainees. This study demonstrates that underrepresented applicants are most influenced by many of the same characteristics as their well-represented peers. However, diversity-related factors still play an important role in the decision-making process. Many residents highlighted the impact microaggressions and mistreatment played in their residency experience, emphasizing the need for residency programs to focus not only on recruitment, but also on the successes and retention of their residents. Only once this is done will the field of orthopaedic surgery find sustained improvement in its diversification efforts.

Arthroplasty for femoral neck fractures is at risk for under restoration of lateral femoral offset.

PURPOSE: The aim of the study was to determine the restoration of hip biomechanics through lateral offset, leg length, and acetabular component position when comparing non-arthroplasty surgeons (NAS) to elective arthroplasty surgeons (EAS). METHODS: 131 patients, with a femoral neck fracture treated with a THA by 7 EAS and 20 NAS, were retrospectively reviewed. 2 blinded observers measured leg-length discrepancy, femoral offset, and acetabular component position. Multivariate logistic regression models examined the association between the surgeon groups and restoration of lateral femoral, acetabular offset, leg length discrepancy, acetabular anteversion, acetabular position, and component size, while adjusting for surgical approach and spinal pathology. RESULTS: NAS under-restored 4.8 mm of lateral femoral offset (43.9 ± 8.7 mm) after THA when compared to the uninjured side (48.7 ± 7.1 mm, p = 0.044). NAS were at risk for under-restoring lateral femoral offset when compared to EAS (p = 0.040). There was no association between lateral acetabular offset, leg length, acetabular position, or component size and surgeon type. CONCLUSIONS: Lateral femoral offset is at risk for under-restoration after THA for femoral neck fractures, when performed by surgeons that do not regularly perform elective THA. This indicates that lateral femoral offset is an under-appreciated contributor to hip instability when performing THA for a femoral neck fracture. Lateral femoral offset deserves as much attention and awareness as acetabular component position since a secondary analysis of our data reveal that preoperative templating and intraoperative imaging did not prevent under-restoration.

Retrograde Intramedullary Nailing Versus Locked Plating for Extreme Distal Periprosthetic Femur Fractures: A Multicenter Retrospective Cohort Study.

OBJECTIVES: To compare clinical and radiographic outcomes after retrograde intramedullary nailing (rIMN) versus locked plating (LP) of "extreme distal" periprosthetic femur fractures, defined as those that contact or extend distal to the anterior flange. DESIGN: Retrospective review. SETTING: Eight academic level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMN or LP. OUTCOME MEASURES AND COMPARISONS: The primary outcome was reoperation to promote healing or to treat infection (reoperation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Outcomes were compared between patients treated with rIMN or LP. RESULTS: Seventy-one patients treated with rIMN and 224 patients treated with LP were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 ± 1.1 vs. LP: 6.0 ± 1.1, P < 0.001) and more patients who were allowed to weight-bear as tolerated immediately postoperatively (rIMN: 45%; LP: 9%, P < 0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group ( P = 0.122). There were no significant differences in nonunion ( P > 0.999), delayed union ( P = 0.079), fixation failure ( P > 0.999), infection ( P = 0.084), or overall reoperation rate ( P > 0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, P = 0.008). CONCLUSIONS: rIMN of extreme distal periprosthetic femur fractures has similar complication rates compared with LP, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Incisional negative pressure wound therapy may not protect against post-operative surgical site complications in bicondylar tibial plateau fractures.

PURPOSE: To determine if incisional negative pressure wound therapy is protective against post-operative surgical site complications following definitive fixation of bicondylar tibial plateau fractures. METHODS: A retrospective analysis of patients diagnosed with an acute bicondylar tibial plateau fracture (AO/OTA 41-C) undergoing ORIF from 2010 to 2020 was performed. Patients received either a standard sterile dressing (SD) or incisional negative pressure wound therapy (iNPWT). Primary outcomes included surgical site infection, osteomyelitis, and wound dehiscence. Secondary outcomes included non-union and return to the operating room. Multivariate logistic regression analyses were performed. RESULTS: 180 patients were included and 22% received iNPWT (n = 40) and 78% received standard dressings (n = 140). iNPWT was more common in active smokers (24.7% vs. 19.3%, p = 0.002) and the SD group was more likely to be lost to follow up (3.6% vs. 0%, p = 0.025). iNPWT was not protective against infection or surgical site complications, and in fact, was associated with higher odds of post-operative infection (OR: 8.96, p = 0.005) and surgical site complications (OR:4.874, p = 0.009) overall. Alcohol abuse (OR: 19, p = 0.005), tobacco use (OR: 4.67, p = 0.009), and time to definitive surgery (OR = 1.21, p = 0.033) were all independent risk factors for post-operative infection. CONCLUSION: In this series of operatively treated bicondylar tibial plateau fractures, iNPWT did not protect against post-operative surgical site complications compared to conventional dressings. Tobacco use, alcohol abuse, and time to definitive surgery, were independent risk factors for post-operative infection. Further studies are needed to determine if iNPWT offers a protective benefit in exclusively high-risk patients with relevant medical and social history.

Efficient Estimation of the Human Circadian Phase via Kalman Filtering.

Circadian rhythms play a vital role in maintaining a person's well-being but remain difficult to quantify accurately. Numerous approaches exist to measure these rhythms, but they often suffer from performance issues on the individual level. This work implements a Steady-State Kalman Filter as a method for estimating the circadian phase shifts from biometric signals. Our framework can automatically fit the filter's parameters to biometric data obtained for each individual, and we were able to consistently estimate the phase shift within 1 hour of melatonin estimates on 100% of all subjects in this study. The estimation method opens up the possibility of real-time control and assessment of the circadian system, as well as chronotherapeutic intervention.Clinical relevance- This establishes a near real-time alternative to melatonin measurements for the estimation of circadian phase shifts, with potential applications in feedback circadian control and chronotherapeutics.

Game of Crowns: Na+ Is Coming! Red NIR-Emissive Hybrid Liquid Crystals Containing Discotic Crown Ethers and Na2Mo6X8iCl6 (Xi = Cl or Br).

Molecular or supramolecular materials that can self-organize into columns such as discotic liquid crystals are of interest for several applications in the field of optoelectronics. We show in this work that red near-infrared (NIR)-emissive metal cluster compounds of general formula Na2Mo6X8iCl6 (Xi = Cl or Br) can be readily complexed with discotic liquid crystals containing a crown ether. Three cavity sizes have been tested with crown ethers bearing 4, 5, or 6 oxygen atoms. In all cases, 1:1 complexes were formed, thanks to the well-known supramolecular interactions existing between the Na+ cations of the metal cluster salt and the crown ether derivatives. All obtained hybrids are homogeneous, emit in the red NIR region, and show liquid crystalline properties on a wider temperature range than their precursors. Charge transport properties have been investigated by using a space charge limited current device. Obtained results demonstrate that metal cluster compounds can enhance the charge carrier mobility by 5 orders of magnitude compared to the native discotic organic ligands. Considering that the presented organic crown ether derivatives are not the best candidates to design optoelectronic devices because of their inherently low conductivity, but that similar compounds were developed to design proton conductive porous framework, our results open promising perspectives for the use of metal cluster compounds in devices dedicated to such a field.

Characterization of three plastic forms: Plasticoncrete, plastimetal and plastisessiles.

Plastic forms, including plastiglomerate, pyroplastic, plasticrusts, anthropoquinas, plastistone and plastitar, were recorded worldwide. These plastic forms derive from geochemical or geophysical interactions such as heat-induced plastic fusion with rock in campfires, incomplete plastic combustion, water motion-driven plastic abrasion in the rocky intertidal zone, plastic deposition in hardened sediments and plastic bonding with tar. Thereby, these interactions can profoundly influence the fate of plastics in the environment. This study characterized three novel plastic forms (plasticoncrete, plastimetal and plastisessiles) discovered on Helgoland island (North Sea). Plasticoncrete consisted of common polyethylene (PE) and polypropylene (PP) fibers hardened in concrete. Plastimetal included PE fibers rusted with metal. Plastisessiles consisted of PE fibers attached to benthic substrates by sessile invertebrates (oysters and polychaetes). Plasticoncrete and plastimetal are the first plastic forms composed of two man-made materials. Plastisessiles show that plastic forms not only result from human- or environment-mediated interactions but also from biological interactions between invertebrates and plastic. All plastic forms (bulk density ≥ 1.4 g/cm3) sunk during floating tests and hardly changed their positions during a 13-day field experiment and 153- to 306-day field monitorings, indicating their local formation, limited mobility and longevity. Still, experimentally detached plastic fibers floated, confirming that the formation of these plastic forms influences the fate of plastic fibers in the environment. Furthermore, the experiment showed that plasticoncrete got deposited in beach sand under wavy and windy conditions, indicating that coastal waves and onshore winds drive plasticoncrete deposition in coastal sediments. We also provide first records of plasticoncrete on Mallorca island (Mediterranean Sea) and plastimetal on Hikoshima island (Sea of Japan), respectively, which show that these plastic forms are no local phenomena. Thereby, our study contributes to the growing fundamental knowledge of plastic forms that is essential to understand the role and fate of these pollutants in coastal habitats worldwide.

Plasticrust generation and degeneration in rocky intertidal habitats contribute to microplastic pollution.

Plasticrusts are a plastic form that consists of plastic encrusting intertidal rocks. To date, plasticrusts have been reported on Madeira island (Atlantic Ocean), Giglio island (Mediterranean Sea) and in Peru (Pacific Ocean) but information on plasticrust sources, generation, degeneration and fate is largely missing. To address these knowledge gaps, we combined plasticrust field surveys, experiments and monitorings along the Yamaguchi Prefecture (Honshu, Japan) coastline (Sea of Japan) with macro-, micro- and spectroscopic analyses in Koblenz, Germany. Our surveys detected polyethylene (PE) plasticrusts that derived from very common PE containers and polyester (PEST) plasticrusts that resulted from PEST-based paint. We also confirmed that plasticrust abundance, cover and distribution were positively related to wave exposure and tidal amplitude. Our experiments showed that plasticrusts are generated by cobbles scratching across plastic containers, plastic containers being dragged across cobbles during beach clean-ups, and waves abrading plastic containers on intertidal rocks. Our monitorings found that plasticrust abundance and cover decreased over time and the macro- and microscopic examinations indicated that detached plasticrusts contribute to microplastic pollution. The monitorings also suggested that hydrodynamics (wave occurrence, tidal height) and precipitation drive plasticrust degeneration. Finally, floating tests revealed that low density (PE) plasticrusts float whereas high density (PEST) plasticrusts sink suggesting that polymer type floatability influences the fate of plasticrusts. By tracking the entire lifespan of plasticrusts for the first time, our study contributes fundamental knowledge of plasticrust generation and degeneration in the rocky intertidal zone and identified plasticrusts as novel microplastic sources.

Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films.

The use of thermally activated delayed fluorescence (TADF) emitters and emitters that show preferential horizontal orientation of their transition dipole moment (TDM) are two emerging strategies to enhance the efficiency of OLEDs. We present the first example of a liquid crystalline multi-resonance TADF (MR-TADF) emitter, DiKTa-LC. The compound possesses a nematic liquid crystalline phase between 80 °C and 110 °C. Importantly, the TDM of the spin-coated film shows preferential horizontal orientation, with an anisotropy factor, a, of 0.28, which is preserved in doped poly(vinylcarbazole) films. Green-emitting (λEL =492 nm) solution-processed OLEDs based on DiKTa-LC showed an EQEmax of 13.6 %. We thus demonstrate for the first time how self-assembly of a liquid crystalline TADF emitter can lead to the so-far elusive control of the orientation of the transition dipole in solution-processed films, which will be of relevance for high-performance solution-processed OLEDs.

External Fixator Usage and Delayed MRI Scans: A National Survey Study.

OBJECTIVE: To report the current state of institutional protocols regarding the use of MRI in patients with external fixation devices (EFDs) in the United States. DESIGN: National Survey Study. PARTICIPANTS: Practicing orthopaedic surgeons frequenting the Orthopaedic Trauma Association website were invited to participate in this study. RESULTS: Sixty-two eligible orthopaedic surgeons completed the survey. No respondents reported any known harmful complications of MRI use with an EFD. Eight respondents (13%) reported at least one early scan termination because of mild warmth or vibration without any lasting complications. Fifty-six respondents (90%) reported delays to care related to MRI-EFD compatibility labeling, and 27 respondents (48%) reported delayed MRI scans in every patient with an EFD who needed one. Twenty-six surgeons (42%) had modified their practice in some way in response to these barriers. Examples include delaying EFD placement until after MRI, relying on CT arthrograms over MRI for surgical planning, and taking patients to the operating room to remove EFDs temporarily and then replace them. Nineteen respondents (31%) had developed formal protocols to address this issue, but having a written protocol was not associated with any decrease in delays ( P = 0.119). Eighty-nine percent of respondents thought there was a need for a national consensus guideline on this issue. CONCLUSION: Despite no previous reports of harmful complications, MRI utilization is frequently delayed or prevented in patients with EFDs in place. This is a pervasive problem nationally, which persists despite the implementation of written institutional protocols. Additional research is needed, potentially at the national level, to address this common issue. LEVEL OF EVIDENCE: V.

Drilling the cement mantle in well-fixed periprosthetic femur fractures is not associated with arthroplasty-related complications.

OBJECTIVE: To determine if screw fixation across a cement mantle is safe and effective during plate fixation of well-fixed periprosthetic femur fractures. DESIGN: Retrospective cohort study. SETTING: Academic Level I Trauma Center. PATIENTS: Twenty-eight patients with AO/OTA 32A[B1] or 32A[C] periprosthetic femur fractures treated with open reduction and internal plate and screw fixation after cemented or uncemented hip arthroplasty. INTERVENTION: Screw placement into the cement mantle during internal fixation. OUTCOME MEASUREMENTS: Primary outcome was revision arthroplasty for aseptic loosening. Secondary outcomes included radiographic evidence of aseptic loosening, infection, nonunion, implant failure, and overall reoperation rate. RESULTS: There were 28 patients who met inclusion criteria. A total of 9 patients had screws placed in the cement mantle while the remaining 19 patients had screws placed around an uncemented stem. At a mean of 3.7-year follow-up, there were no cases of revision arthroplasty or aseptic loosening in either group. There were no significant differences in rates of infection, nonunion, implant failure, or reoperation rate between patients who had screw placement into a cement mantle vs around an uncemented stem. CONCLUSION: Drilling into the cement mantle during fixation of a periprosthetic femur fracture around a well-fixed cemented hip stem appears safe and effective. When possible, surgeons can consider bicortical screws around a cemented stem, given the biomechanical advantages over unicortical screw or cerclage fixation. Larger prospective trials confirming the safety of this technique are warranted prior to routine implementation. LEVEL OF EVIDENCE: III.

COVID-19 Risk Perception and Support for COVID-19 Mitigation Measures among Local Government Officials in the U.S.: A Test of a Cultural Theory of Risk.

This study relies on a cultural theory of risk to examine how cultural biases (hierarchy, individualism, egalitarianism, and fatalism) of local government officials affect their COVID-19 risk perception and support for COVID-19 mitigation measures. After controlling for partisanship, religiosity, and other factors, the analysis of survey data from county governments in the U.S. revealed that cultural biases matter. Officials with egalitarian and hierarchical cultural biases report higher support for adopting COVID-19 mitigation measures, while those with individualistic cultural biases report lower support. These findings highlight the need to understand cultural worldviews and develop cultural competencies necessary for governing traumatic events.