Distal Tibiofibular Syndesmosis Injuries in the National Football League (NFL): A Spectrum of Pathology That Correlates With Time to Return to Full Participation.

BACKGROUND: Studies routinely evaluate high ankle sprains in isolation, but recent data suggest that these injuries are often associated with concomitant pathology, potentially influencing return to full participation. HYPOTHESIS: In National Football League (NFL) players, isolated high ankle sprains are rare and syndesmosis injuries with concomitant pathology will result in increased time to return to full participation. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: Distal tibiofibular syndesmosis injuries sustained by NFL players between 2017 and 2019 were identified through NFL Injury Surveillance Database queries and verified with video analysis. Each injury underwent a comprehensive magnetic resonance imaging (MRI) review. Regression modeling was utilized to explore the influence of numerous imaging findings on time to return to full participation. RESULTS: There were 83 external rotation ankle injuries involving the syndesmosis. Isolated distal tibiofibular syndesmosis injuries were rare (n = 11; 13%) and more often associated with other ligamentous injury (deltoid ligament and lateral ligamentous complex) and/or fractures. Regression modeling resulted in clustering of 3 injury pattern groups for time to return to full participation across numerous imaging findings: syndesmosis injury-fracture combinations (250 days [interquartile range [IQR,] 142-266 days]), syndesmosis injury with complete deep deltoid tear or acute diastasis (175 days [IQR, 20-248 days]), and all other syndesmosis injuries (27 days [IQR, 18-46 days]). CONCLUSION: In NFL athletes with external rotation ankle injuries, isolated distal tibiofibular syndesmosis injuries were rare and more often associated with concomitant pathology. Time to return to full participation was affected by an associated fracture and complete deep deltoid ligament tear or diastasis but no other relevant MRI variables such as lateral ligament complex involvement or the presence of osteochondral lesions or bone contusions.

Low-latency gravitational wave alert products and their performance at the time of the fourth LIGO-Virgo-KAGRA observing run.

Multimessenger searches for binary neutron star (BNS) and neutron star-black hole (NSBH) mergers are currently one of the most exciting areas of astronomy. The search for joint electromagnetic and neutrino counterparts to gravitational wave (GW)s has resumed with ALIGO's, AdVirgo's and KAGRA's fourth observing run (O4). To support this effort, public semiautomated data products are sent in near real-time and include localization and source properties to guide complementary observations. In preparation for O4, we have conducted a study using a simulated population of compact binaries and a mock data challenge (MDC) in the form of a real-time replay to optimize and profile the software infrastructure and scientific deliverables. End-toend performance was tested, including data ingestion, running online search pipelines, performing annotations, and issuing alerts to the astrophysics community. We present an overview of the low-latency infrastructure and the performance of the data products that are now being released during O4 based on the MDC. We report the expected median latency for the preliminary alert of full bandwidth searches (29.5 s) and show consistency and accuracy of released data products using the MDC. We report the expected median latency for triggers from early warning searches (-3.1 s), which are new in O4 and target neutron star mergers during inspiral phase. This paper provides a performance overview for LIGO-Virgo-KAGRA (LVK) low-latency alert infrastructure and data products using theMDCand serves as a useful reference for the interpretation of O4 detections.

An updated nuclear-physics and multi-messenger astrophysics framework for binary neutron star mergers.

The multi-messenger detection of the gravitational-wave signal GW170817, the corresponding kilonova AT2017gfo and the short gamma-ray burst GRB170817A, as well as the observed afterglow has delivered a scientific breakthrough. For an accurate interpretation of all these different messengers, one requires robust theoretical models that describe the emitted gravitational-wave, the electromagnetic emission, and dense matter reliably. In addition, one needs efficient and accurate computational tools to ensure a correct cross-correlation between the models and the observational data. For this purpose, we have developed the Nuclear-physics and Multi-Messenger Astrophysics framework NMMA. The code allows incorporation of nuclear-physics constraints at low densities as well as X-ray and radio observations of isolated neutron stars. In previous works, the NMMA code has allowed us to constrain the equation of state of supranuclear dense matter, to measure the Hubble constant, and to compare dense-matter physics probed in neutron-star mergers and in heavy-ion collisions, and to classify electromagnetic observations and perform model selection. Here, we show an extension of the NMMA code as a first attempt of analyzing the gravitational-wave signal, the kilonova, and the gamma-ray burst afterglow simultaneously. Incorporating all available information, we estimate the radius of a 1.4M⊙ neutron star to be [Formula: see text] km.

Minutes-duration optical flares with supernova luminosities.

In recent years, certain luminous extragalactic optical transients have been observed to last only a few days1. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae), whose timescale is weeks2. Some short-duration transients, most notably AT2018cow (ref. 3), show blue optical colours and bright radio and X-ray emission4. Several AT2018cow-like transients have shown hints of a long-lived embedded energy source5, such as X-ray variability6,7, prolonged ultraviolet emission8, a tentative X-ray quasiperiodic oscillation9,10 and large energies coupled to fast (but subrelativistic) radio-emitting ejecta11,12. Here we report observations of minutes-duration optical flares in the aftermath of an AT2018cow-like transient, AT2022tsd (the 'Tasmanian Devil'). The flares occur over a period of months, are highly energetic and are probably nonthermal, implying that they arise from a near-relativistic outflow or jet. Our observations confirm that, in some AT2018cow-like transients, the embedded energy source is a compact object, either a magnetar or an accreting black hole.

A very luminous jet from the disruption of a star by a massive black hole.

Tidal disruption events (TDEs) are bursts of electromagnetic energy that are released when supermassive black holes at the centres of galaxies violently disrupt a star that passes too close1. TDEs provide a window through which to study accretion onto supermassive black holes; in some rare cases, this accretion leads to launching of a relativistic jet2-9, but the necessary conditions are not fully understood. The best-studied jetted TDE so far is Swift J1644+57, which was discovered in γ-rays, but was too obscured by dust to be seen at optical wavelengths. Here we report the optical detection of AT2022cmc, a rapidly fading source at cosmological distance (redshift z = 1.19325) the unique light curve of which transitioned into a luminous plateau within days. Observations of a bright counterpart at other wavelengths, including X-ray, submillimetre and radio, supports the interpretation of AT2022cmc as a jetted TDE containing a synchrotron 'afterglow', probably launched by a supermassive black hole with spin greater than approximately 0.3. Using four years of Zwicky Transient Facility10 survey data, we calculate a rate of [Formula: see text] per gigapascals cubed per year for on-axis jetted TDEs on the basis of the luminous, fast-fading red component, thus providing a measurement complementary to the rates derived from X-ray and radio observations11. Correcting for the beaming angle effects, this rate confirms that approximately 1 per cent of TDEs have relativistic jets. Optical surveys can use AT2022cmc as a prototype to unveil a population of jetted TDEs.

Constraining neutron-star matter with microscopic and macroscopic collisions.

Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not probed only in astrophysical observations, but also in terrestrial heavy-ion collision experiments. Here we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars1-9 and from heavy-ion collisions of gold nuclei at relativistic energies10,11 with microscopic nuclear theory calculations12-17 to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent observations by the Neutron Star Interior Composition Explorer mission5-8,18. Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars.

Candidate Tidal Disruption Event AT2019fdr Coincident with a High-Energy Neutrino.

The origins of the high-energy cosmic neutrino flux remain largely unknown. Recently, one high-energy neutrino was associated with a tidal disruption event (TDE). Here we present AT2019fdr, an exceptionally luminous TDE candidate, coincident with another high-energy neutrino. Our observations, including a bright dust echo and soft late-time x-ray emission, further support a TDE origin of this flare. The probability of finding two such bright events by chance is just 0.034%. We evaluate several models for neutrino production and show that AT2019fdr is capable of producing the observed high-energy neutrino, reinforcing the case for TDEs as neutrino sources.

A 62-minute orbital period black widow binary in a wide hierarchical triple.

Over a dozen millisecond pulsars are ablating low-mass companions in close binary systems. In the original 'black widow', the eight-hour orbital period eclipsing pulsar PSR J1959+2048 (PSR B1957+20)1, high-energy emission originating from the pulsar2 is irradiating and may eventually destroy3 a low-mass companion. These systems are not only physical laboratories that reveal the interesting results of exposing a close companion star to the relativistic energy output of a pulsar, but are also believed to harbour some of the most massive neutron stars4, allowing for robust tests of the neutron star equation of state. Here we report observations of ZTF J1406+1222, a wide hierarchical triple hosting a 62-minute orbital period black widow candidate, the optical flux of which varies by a factor of more than ten. ZTF J1406+1222 pushes the boundaries of evolutionary models5, falling below the 80-minute minimum orbital period of hydrogen-rich systems. The wide tertiary companion is a rare low-metallicity cool subdwarf star, and the system has a Galactic halo orbit consistent with passing near the Galactic Centre, making it a probe of formation channels, neutron star kick physics6 and binary evolution.

Nitinol, Stainless Steel, and Titanium Kirschner Wire Durability.

Kirschner wires (K wires) are a common fixation device in foot and ankle surgery, particularly in lesser-toe fixation. Fatigue failure is a known complication of this fixation. The material properties of the K wire are a factor in the strength and durability of the wire. The purpose of this study is to compare the durability of K wires made of stainless steel, titanium, and Nitinol. Ten samples each of stainless steel, titanium. and Nitinol underwent cyclic durability testing using a rotating beam approach, and S-N curves (applied stress vs the number of cycles to failure) were generated. The results demonstrate that, generally, Nitinol K wires have a shorter life for the same applied stress than the stainless steel or titanium wires. Titanium had a longer life at low stresses compared with stainless steel, and stainless steel had a longer life at higher stresses. This study provides comparative durability data for K wires made of different metals, which have not been previously reported. Although there was a statistically significant difference in durability for wires used in K wire fixation, all 3 metal types are reasonable choices for temporary K wire fixation.Levels of Evidence: Level 5: Mechanical study.

Multimessenger constraints on the neutron-star equation of state and the Hubble constant.

Observations of neutron-star mergers with distinct messengers, including gravitational waves and electromagnetic signals, can be used to study the behavior of matter denser than an atomic nucleus and to measure the expansion rate of the Universe as quantified by the Hubble constant. We performed a joint analysis of the gravitational-wave event GW170817 with its electromagnetic counterparts AT2017gfo and GRB170817A, and the gravitational-wave event GW190425, both originating from neutron-star mergers. We combined these with previous measurements of pulsars using x-ray and radio observations, and nuclear-theory computations using chiral effective field theory, to constrain the neutron-star equation of state. We found that the radius of a 1.4-solar mass neutron star is [Formula: see text] km at 90% confidence and the Hubble constant is [Formula: see text] at 1σ uncertainty.

Locked Dorsal Compression Plate Arthrodesis for Degenerative Arthritis of the Midfoot.

Midfoot arthrodesis is the accepted surgical treatment for symptomatic midfoot arthritis. The published literature has focused on joint-spanning static fixation. Several companies have developed diamond-shaped locked dorsal compression plates, which allow for longitudinal joint compression. After dorsal plate insertion, a spreader device opens the arms of the plate mediolaterally, which allows the plate to compress longitudinally. This work describes outcomes of such locked dorsal compression plates for midfoot arthritis at a single institution. We reviewed 62 patients who underwent midfoot arthrodesis for symptomatic midfoot arthritis using locked dorsal compression plates over a 7-year period. A total of 173 joints were spanned for fusion. The primary outcome measure was radiographic union and visual analog scale pain scores. Characteristics of patients who experienced nonunion versus those who had union were evaluated. Of the 173 joints, there was a 81.5% fusion rate (141/173 joints) and 14 patients experienced nonunion. There was a statistically significant difference in the average number of joints spanned in patients with nonunion (3.6) and patients with union (2.5) (p = .02). Locked dorsal compression plate arthrodesis is a viable technique for achieving midfoot fusion. This mechanical method of compression does not, however, lend itself to improved fusion rates compared with prior reports. A greater number of arthrodesis sites is associated with a higher nonunion rate. Emerging technology using newer materials and improved biomechanical designs may show improved results.

Measuring the Hubble constant with a sample of kilonovae.

Kilonovae produced by the coalescence of compact binaries with at least one neutron star are promising standard sirens for an independent measurement of the Hubble constant (H0). Through their detection via follow-up of gravitational-wave (GW), short gamma-ray bursts (sGRBs) or optical surveys, a large sample of kilonovae (even without GW data) can be used for H0 contraints. Here, we show measurement of H0 using light curves associated with four sGRBs, assuming these are attributable to kilonovae, combined with GW170817. Including a systematic uncertainty on the models that is as large as the statistical ones, we find [Formula: see text] and [Formula: see text] for two different kilonova models that are consistent with the local and inverse-distance ladder measurements. For a given model, this measurement is about a factor of 2-3 more precise than the standard-siren measurement for GW170817 using only GWs.

Incidence of Lower Extremity Injury in the National Football League: 2015 to 2018.

BACKGROUND: Lower extremity injuries are the most common injuries in professional sports and carry a high burden to players and teams in the National Football League (NFL). Injury prevention strategies can be refined by a foundational understanding of the occurrence and effect of these injuries on NFL players. PURPOSE: To determine the incidence of specific lower extremity injuries sustained by NFL players across 4 NFL seasons. STUDY DESIGN: Descriptive epidemiology study. METHODS: This retrospective, observational study included all time-loss lower extremity injuries that occurred during football-related activities during the 2015 through 2018 seasons. Injury data were collected prospectively through a leaguewide electronic health record (EHR) system and linked with NFL game statistics and player participation to calculate injury incidence per season and per 10,000 player-plays for lower extremity injuries overall and for specific injuries. Days lost due to injury were estimated through 2018 for injuries occurring in the 2015 to 2017 seasons. RESULTS: An average of 2006 time-loss lower extremity injuries were reported each season over this 4-year study, representing a 1-season risk of 41% for an NFL player. Incidence was stable from 2015 to 2018, with an estimated total missed time burden each NFL season of approximately 56,700 player-days lost. Most (58.7%) of these injuries occurred during games, with an overall higher rate of injuries observed in preseason compared with regular season (11.5 vs 9.4 injuries per 10,000 player-plays in games). The knee was the most commonly injured lower extremity region (29.3% of lower body injuries), followed by the ankle (22.4%), thigh (17.2%), and foot (9.1%). Hamstring strains were the most common lower extremity injury, followed by lateral ankle sprains, adductor strains, high ankle sprains, and medial collateral ligament tears. CONCLUSION: Lower extremity injuries affect a high number of NFL players, and the incidence did not decrease over the 4 seasons studied. Prevention and rehabilitation protocols for these injuries should continue to be prioritized.

Mallet Toes, Hammertoes, Neuromas, and Metatarsophalangeal Joint Instability: 40 Years of Development in Forefoot Surgery.

BACKGROUND: Today's foot and ankle surgeon has an enhanced understanding of forefoot pathology and treatment options compared to surgeons who practiced in previous decades. This paper summarizes developments in forefoot surgery in the past 40 years, specifically in treatments for mallet toe, hammertoe, neuroma, and metatarsophalangeal joint instability. MATERIALS AND METHODS: A review of the literature was conducted using the PubMed search engine, with key terms including, "mallet toe," "hammertoe," "neuroma," "metatarsophalangeal joint instability," "plantar plate," and "forefoot surgery." Chapters in major orthopaedic textbooks covering these topics were also reviewed. We then chronicled the history of the diagnosis and treatment of these pathologies, with a focus on the past 40 years. CONCLUSIONS: There have been major advances in understanding and treating forefoot pathologies in the past four decades; however, there remain areas for improvement both in the diagnosis and treatment of these problems. LEVEL OF EVIDENCE: Level V, meta-synthesis.

General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system.

General relativity1 predicts that short-orbital-period binaries emit considerable amounts of gravitational radiation. The upcoming Laser Interferometer Space Antenna2 (LISA) is expected to detect tens of thousands of such systems3 but few have been identified4, of which only one5 is eclipsing-the double-white-dwarf binary SDSS J065133.338+284423.37, which has an orbital period of 12.75 minutes. Here we report the discovery of an eclipsing double-white-dwarf binary system, ZTF J153932.16+502738.8, with an orbital period of 6.91 minutes. This system has an orbit so compact that the entire binary could fit within the diameter of the planet Saturn. The system exhibits a deep eclipse, and a double-lined spectroscopic nature. We see rapid orbital decay, consistent with that expected from general relativity. ZTF J153932.16+502738.8 is a strong source of gravitational radiation close to the peak of LISA's sensitivity, and we expect it to be detected within the first week of LISA observations, once LISA launches in approximately 2034.

Rigid Internal Fixation of Proximal Crescentic Metatarsal Osteotomy in Hallux Valgus Correction.

BACKGROUND: The purpose of this study was to evaluate outcomes utilizing a low-profile titanium plate and screw construct for rigid fixation of first ray proximal crescentic osteotomies in the treatment of hallux valgus. METHODS: Forty-eight patients (53 feet) with mild to severe hallux valgus were prospectively enrolled and completed 12-month follow-up. All were treated with a proximal crescentic osteotomy, fixed with a low-profile titanium plate, distal soft tissue correction, with or without an Akin osteotomy. Recorded outcomes included change in first ray dorsiflexion angles, need for hardware removal, radiographic and clinical evaluation, pain, and American Orthopaedic Foot & Ankle Society (AOFAS) scores. RESULTS: All patients achieved radiographic union of their osteotomy. An Akin osteotomy was performed in 83% of patients. Seventeen feet (32%) had hardware removed. First ray dorsiflexion angles increased from a mean of 1.6 degrees preoperatively to 5.0 degrees postoperatively (P < .001). Dorsal malunion, defined as change in dorsiflexion angle greater than 1 standard deviation above the mean, occurred in 7 feet. The mean hallux valgus angle improved from 29 to 9 degrees (P < .001). The mean 1-2 intermetatarsal angle decreased from 14 to 6 degrees (P < .001). The first metatarsophalangeal joint range of motion decreased from 77 to 59 degrees (P < .001). The mean visual analog scale score improved from 4 to 0.7 (P < .0001). The mean AOFAS score improved from 55 to 89 points (P < .001). CONCLUSION: Proximal crescentic metatarsal osteotomy, fixed with a low-profile titanium plate and screw construct, with distal soft tissue repair, and Akin osteotomy as indicated, was a safe and reliable method for operative treatment of hallux valgus. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Synthetic Turf: History, Design, Maintenance, and Athlete Safety.

CONTEXT:: Synthetic turf has become an increasingly common playing surface for athletics and has changed dramatically since its introduction more than 50 years ago. Along with changes to surface design, maintenance needs and recommendations have become more standardized and attentive both to upkeep and player-level factors. In particular, synthetic turf maintenance as it relates to athlete health and safety is an important consideration at all levels of play. EVIDENCE ACQUISITION:: A literature search of MEDLINE and PubMed for publications between the years 1990 and 2018 was conducted. Keywords included s ynthetic turf, artificial turf, field turf, and playing surface. Additionally, expert opinion through systematic interviews and practical implementation were obtained on synthetic turf design and maintenance practices in the National Football League. STUDY DESIGN:: Clinical review. LEVEL OF EVIDENCE:: Level 5. RESULTS:: Synthetic turf has changed considerably since its inception. Playing surface is a critical component of the athletic environment, playing a role both in performance and in athlete safety. There are several important structural considerations of third-generation synthetic turf systems currently used in the United States that rely heavily on strong and consistent maintenance. A common misconception is that synthetic turf is maintenance free; in fact, however, these surfaces require routine maintenance. Whether athletes experience more injuries on synthetic over natural surfaces is also of interest among various levels and types of sport. CONCLUSION:: Modern synthetic turf is far different than when originally introduced. It requires routine maintenance, even at the level of local athletics. It is important for sports medicine personnel to be familiar with playing surface issues as they are often treating athletes at the time of injury and should maintain a level of awareness of contemporary research and practices regarding the relationships between synthetic turf and injury.

Higher Rates of Lower Extremity Injury on Synthetic Turf Compared With Natural Turf Among National Football League Athletes: Epidemiologic Confirmation of a Biomechanical Hypothesis.

BACKGROUND: Biomechanical studies have shown that synthetic turf surfaces do not release cleats as readily as natural turf, and it has been hypothesized that concomitant increased loading on the foot contributes to the incidence of lower body injuries. This study evaluates this hypothesis from an epidemiologic perspective, examining whether the lower extremity injury rate in National Football League (NFL) games is greater on contemporary synthetic turfs as compared with natural surfaces. HYPOTHESIS: Incidence of lower body injury is higher on synthetic turf than on natural turf among elite NFL athletes playing on modern-generation surfaces. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Lower extremity injuries reported during 2012-2016 regular season games were included, with all 32 NFL teams reporting injuries under mandated, consistent data collection guidelines. Poisson models were used to construct crude and adjusted incidence rate ratios (IRRs) to estimate the influence of surface type on lower body injury groupings (all lower extremity, knee, ankle/foot) for any injury reported as causing a player to miss football participation as well as injuries resulting in ≥8 days missed. A secondary analysis was performed on noncontact/surface contact injuries. RESULTS: Play on synthetic turf resulted in a 16% increase in lower extremity injuries per play than that on natural turf (IRR, 1.16; 95% CI, 1.10-1.23). This association between synthetic turf and injury remained when injuries were restricted to those that resulted in ≥8 days missed, as well as when categorizations were narrowed to focus on distal injuries anatomically closer to the playing surface (knee, ankle/foot). The higher rate of injury on synthetic turf was notably stronger when injuries were restricted to noncontact/surface contact injuries (IRRs, 1.20-2.03; all statistically significant). CONCLUSION: These results support the biomechanical mechanism hypothesized and add confidence to the conclusion that synthetic turf surfaces have a causal impact on lower extremity injury.

Development of a Footwear Sizing System in the National Football League.

CONTEXT:: Footwear performance and injury mitigation may be compromised if the footwear is not properly sized for an athlete. Additionally, poor fit may result in discomfort and foot injury such as fifth metatarsal stress fracture, foot deformities, turf toe, and blisters. Current footwear fitting methods consist of foot length and width measurements, which may not properly describe the shape of the individual foot, correlated with shoe size descriptors that are not standardized. Footwear manufacturers employ a range of sizing rubrics, which introduces shoe size and shape variability between and even within footwear companies. This article describes the synthesis of literature to inform the development and deployment of an objective footwear fitting system in the National Football League (NFL). The process may inform athletic footwear fitting at other levels of play and in other sports. EVIDENCE ACQUISITION:: Literature related to footwear fitting, sizing, and foot scanning from 1980 through 2017 was compiled using electronic databases. Reference lists of articles were examined for additional relevant studies. Sixty-five sources are included in this descriptive review. STUDY TYPE:: Descriptive review. LEVEL OF EVIDENCE:: Level 5. RESULTS:: Current methods of footwear fitting and variability in the size and shape of athletic footwear complicate proper fitting of footwear to athletes. An objective measurement and recommendation system that can match the 3-dimensional shape of an athlete's foot to the internal shape of available shoe models can provide important guidance for footwear selection. One such system has been deployed in the NFL. CONCLUSION:: An objective footwear fitting system based on 3-dimensional shape matching of feet and shoes can facilitate the selection of footwear that properly fits an athlete's foot.