Percutaneous elevation of radial head fractures without fixation - a promising technique.

The aim of the study is to describe the surgical technique and to report the outcomes of triceps reflecting anconeus pedicle (TRAP) approach for intercondylar fractures of the humerus. Twenty two patients with intercondylar fractures of the humerus were operated on by open reduction via the TRAP approach and internal fixation with dual precontoured locking plates. Data were collected on union time, postoperative complications, range of motion (ROM), triceps power, and objective clinical measurement. All fractures were united with a mean union time of 16.5 weeks (range 12-22). All patients had good-to-excellent Mayo Elbow Performance (MEP) score results with a mean ROM of 118.2 degrees (range 90-135). Triceps power was grade 5 in 16 patients and grade 4 in 6. There were 3 transient ulnar nerve palsy and 1 heterotopic ossification. TRAP approach is safe and effective in terms of utility for articular reduction, restoration of elbow motion, and triceps function for intercondylar fractures of the humerus.

Total hip arthroplasty in acute acetabulum fractures: a systematic review.

INTRODUCTION: The incidence of acetabular fractures has increased significantly in recent years due to demographic change. It can be divided into high-energy acetabular fractures primarily seen in adult patients versus geriatric patients mostly suffering from low-energy trauma. Historically, acetabular fractures have been treated either non-operatively or surgically following open reduction and internal fixation (ORIF), whereas nowadays total hip arthroplasty (THA) provides a true alternative. Aim of this study was to perform a systematic review on the outcome following THA in acute acetabulum fractures. METHODS: PubMed/MEDLINE, Cochrane and Google databases were systematically searched on December 9, 2021. The key terms were [acetabular fracture] AND [[arthroplasty] OR [fixation]]. All retrospective and prospective original studies in English and German were analyzed the outcome following THA in acute acetabulum fractures were included. RESULTS: A total of 2459 studies were screened, which includes 15 studies that met the inclusion criteria with a total of 590 patients at a mean age of 61.3 years (SD 11.48). Most studies described good to excellent results. Especially, THA allows elderly patients quicker mobilization and rehabilitation as well as symptomatic relief, as compared to ORIF or non-operative treatment. Patients who underwent non-operative treatment showed better results compared to those who underwent ORIF initially. CONCLUSION: In acetabulum fractures, THA provides a good alternative with very good results when patients are carefully selected. Good to excellent outcomes are reported for both acute and delayed use of THA in elderly patients. LEVEL OF EVIDENCE: Level 2, systematic review.

Combining radiographic and CT measurements to rival MRI for the diagnosis of acute isolated syndesmotic injury.

BACKGROUND: Acute isolated syndesmotic injuries (AISIs) have a high potential to be misdiagnosed or underdiagnosed at initial presentation to the hospital. Although magnetic resonance imaging (MRI) is the gold standard in noninvasive diagnostics, it is not always available immediately and is much more expensive than other imaging modalities. This study identifies improvements in conventional radiography and computed tomography (CT) to diagnose AISI and aims to reduce the number of MRI scans needed to verify the diagnosis. METHODS: A retrospective case match control study was conducted by searching our trauma database between 2008 and 2022. A study group of patients with AISI (n = 64) and a control group of patients without AISI (n = 76) were formed to generate an equal number of images from both groups (62 radiographs and 22 CT scans). A total of 16 parameters that quantify the distal tibiofibular relation in injured and uninjured ankles were analyzed. For statistical analysis, a two-sided t-test was applied to calculate significant differences (p < 0.05). In a further step, a receiver operating characteristic curve (ROC) was used to determine cut-off values for the most significant parameters. RESULTS: The most significant measurement (p < 0.001) on axial CT scans was the syndesmotic area (SA). The ROC curve revealed an area under the curve (AUC) of 0.94 (95% CI 0.86-1.0) and a cut-off value of 71.68 mm2 that shows a sensitivity and specificity of 95.5% and 81.8%, respectively. CONCLUSION: This study suggests that radiographic imaging could represent an equally accurate alternative to MRI. These methods might generate the correct diagnosis faster due to their availability and inexpensiveness. By applying our new cut-off values in a clinical setting, the number of underdiagnosed and untreated unstable syndesmotic injuries could be reduced. LEVEL OF EVIDENCE: III, retrospective comparative study.

Variation of blubber thickness for three marine mammal species in the southern Baltic Sea.

Evaluating populational trends of health condition has become an important topic for marine mammal populations under the Marine Strategy Framework Directive (MSFD). In the Baltic Sea, under the recommendation of Helsinki Commission (HELCOM), efforts have been undertaken to use blubber thickness as an indicator of energy reserves in marine mammals. Current values lack geographical representation from the entire Baltic Sea area and a large dataset is only available for grey seals (Halichoerus grypus) from Sweden and Finland. Knowledge on variation of blubber thickness related to geography throughout the Baltic Sea is important for its usage as an indicator. Such evaluation can provide important information about the energy reserves, and hence, food availability. It is expected that methodological standardization under HELCOM should include relevant datasets with good geographical coverage that can also account for natural variability in the resident marine mammal populations. In this study, seasonal and temporal trends of blubber thickness were evaluated for three marine mammal species-harbor seal (Phoca vitulina), grey seal (Halichoerus grypus) and harbor porpoise (Phocoena phocoena)-resident in the southern Baltic Sea collected and investigated under stranding networks. Additionally, the effects of age, season and sex were analyzed. Seasonal variation of blubber thickness was evident for all species, with harbor seals presenting more pronounced effects in adults and grey seals and harbor porpoises presenting more pronounced effects in juveniles. For harbor seals and porpoises, fluctuations were present over the years included in the analysis. In the seal species, blubber thickness values were generally higher in males. In harbor seals and porpoises, blubber thickness values differed between the age classes: while adult harbor seals displayed thicker blubber layers than juveniles, the opposite was observed for harbor porpoises. Furthermore, while an important initial screening tool, blubber thickness assessment cannot be considered a valid methodology for overall health assessment in marine mammals and should be complemented with data on specific health parameters developed for each species.

In vitro forestomach digestion experiments give less-biased estimates of food composition in odontocetes.

Diet composition of odontocetes is usually inferred from stomach content analyses and accounts for digestion rates derived from in vitro digestion experiments based on seal physiology. However, pinnipeds, being carnivores, have only one stomach compartment, while odontocetes, being cetartiodactyla, have up to four. Inappropriate extrapolation from digestion processes in simulated seal stomachs may result in biased estimates of odontocete diets. We simulated a forestomach accounting for muscle contractions and a pH=4 using in vitro experiments with three fish species. Whiting (Merlangius merlangus), black goby (Gobius niger) and sprat (Sprattus sprattus) showed highly variable exponential, sigmoid or linear digestion functions, and high digestion rates, taking between 50 and 230 min for completed digestion. Previous pinniped models (pH=2, lacking simulated muscular digestion) showed much slower and more similar digestion process. Our results suggest that present biomass intake estimates of odontocetes are biased towards bigger and fattier fish and need to be revised in general.

The Animal Audiogram Database: A community-based resource for consolidated audiogram data and metadata.

Knowledge of hearing ability, as represented in audiograms, is essential for understanding how animals acoustically perceive their environment, predicting and counteracting the effects of anthropogenic noise, and managing wildlife. Audiogram data and relevant background information are currently only available embedded in the text of individual scientific publications in various unstandardized formats. This heterogeneity makes it hard to access, compare, and integrate audiograms. The Animal Audiogram Database (https://animalaudiograms.org) assembles published audiogram data, metadata about the corresponding experiments, and links to the original publications in a consistent format. The database content is the result of an extensive survey of the scientific literature and manual curation of the audiometric data found therein. As of November 1, 2021, the database contains 306 audiogram datasets from 34 animal species. The scope and format of the provided metadata and design of the database interface were established by active research community involvement. Options to compare audiograms and download datasets in structured formats are provided. With the focus currently on vertebrates and hearing in underwater environments, the database is drafted as a free and open resource for facilitating the review and correction of the contained data and collaborative extension with audiogram data from any taxonomic group and habitat.

Estimating the abundance of the critically endangered Baltic Proper harbour porpoise (Phocoena phocoena) population using passive acoustic monitoring.

Knowing the abundance of a population is a crucial component to assess its conservation status and develop effective conservation plans. For most cetaceans, abundance estimation is difficult given their cryptic and mobile nature, especially when the population is small and has a transnational distribution. In the Baltic Sea, the number of harbour porpoises (Phocoena phocoena) has collapsed since the mid-20th century and the Baltic Proper harbour porpoise is listed as Critically Endangered by the IUCN and HELCOM; however, its abundance remains unknown. Here, one of the largest ever passive acoustic monitoring studies was carried out by eight Baltic Sea nations to estimate the abundance of the Baltic Proper harbour porpoise for the first time. By logging porpoise echolocation signals at 298 stations during May 2011-April 2013, calibrating the loggers' spatial detection performance at sea, and measuring the click rate of tagged individuals, we estimated an abundance of 71-1105 individuals (95% CI, point estimate 491) during May-October within the population's proposed management border. The small abundance estimate strongly supports that the Baltic Proper harbour porpoise is facing an extremely high risk of extinction, and highlights the need for immediate and efficient conservation actions through international cooperation. It also provides a starting point in monitoring the trend of the population abundance to evaluate the effectiveness of management measures and determine its interactions with the larger neighboring Belt Sea population. Further, we offer evidence that design-based passive acoustic monitoring can generate reliable estimates of the abundance of rare and cryptic animal populations across large spatial scales.

Femoral Neck Stress Fracture of a Male, Healthy Marathon Runner - Case Report and Literature Review.

In the present report, a case of a healthy, 38-year-old male recreational marathon runner who presented in the emergency department is discussed. He was diagnosed with a stress fracture of the femoral neck and treated surgically using a dynamic hip screw (DHS). One year after surgery, the patient was able to return to most of his previous sports activities. In the present report, the existing literature on the subject is exhibited and the points of interest in terms of incidence, risk factors, diagnosis, classification, treatment, and long-term outcome are analyzed. We suggest operative treatment of stress fractures of the femoral neck even in cases of complete undisplaced ones. This way, the risk of a displacement is counteracted, and patients can quickly return to daily activities without having to withstand long-term immobilization.

E-scooter incidents in Berlin: an evaluation of risk factors and injury patterns.

BACKGROUND: E-scooters have emerged as a frequently used vehicle in German cities due to their high availability and easy access. However, investigations about the causes and mechanisms of E-scooter incidents and their trauma-specific consequences are rare. METHODS: We analysed all patients involved in E-scooter incidents from June to December 2019 who presented to four inner-city EDs in Berlin. The prospective data included patient-related and incident-related data, information on injury patterns and therapy, responses in a voluntary questionnaire concerning E-scooter use and general traffic experience. RESULTS: 248 patients (129 males; median age 29 years (5-81)) were included: 41% were tourists and 4% were children. Most incidents (71%) occurred between July and September 2019, the majority occurring at weekends (58%). The injury pattern was mostly multifocal, affecting the lower (42%) and upper limbs (37%) and the head (40%). Traumatic brain injury was associated with alcohol consumption. Inpatient admission was recorded in 25%, surgery in 23%. CONCLUSION: This study has defined the incidence of injury related to E-scooter use in a major European city. Stricter laws governing the use of E-scooters, the wearing of helmets and technical modifications to the E-scooter platforms might decrease E-scooter-associated incidents and resulting injuries in the future. TRIAL REGISTRATION NUMBER: German Clinical Trials Registry (DRKS00018061).

Nematode Parasites in Baltic Sea Mammals, Grey Seal (Halichoerus grypus (Fabricius, 1791)) and Harbour Porpoise (Phocoena phocoena (L.)), from the German Coast.

PURPOSE: Endoparasitic nematodes of six harbour porpoises Phocoena phocoena and four grey seals Halichoerus grypus, stranded at the eastern coast of the Baltic Sea in Germany in winter 2019, were analysed in order to identify nematode parasites and to compare with recent studies from the same area. METHODS: Endoparasitic nematodes were identified by using both morphological and molecular characters. The successfully obtained sequences of the rDNA marker regions ITS-1, 5.8S, ITS-2 from 29 anisakid and the rDNA marker region ITS-2 of 11 pseudalid nematodes were amplified. RESULTS: Analyses revealed the presence of three parasite species, the anisakid nematode Contracaecum osculatum from grey seals and the pseudalid nematodes Pseudalius inflexus and Stenurus minor from the harbour porpoises. Other anisakid nematodes regularly occurring in the Baltic Sea, e.g. Anisakis simplex or Pseudoterranova decipiens, were not found. CONCLUSIONS: The prevalence of 100% and a severe parasite load in grey seals demonstrated a very high C. osculatum infection of Baltic Sea fish as their regular prey. Prevalence of 33% for parasites in harbour porpoises and minor infection rates, combined with a distinct lack of anisakid nematodes, are typical for the current situation of the porpoise parasite fauna in the Baltic Sea. Invasive parasite species as possible indicators for climate change could not be detected.

No need to shout? Harbor porpoises (Phocoena phocoena) echolocate quietly in confined murky waters of the Wadden Sea.

Porpoise echolocation parameters may vary depending on their acoustic habitat and predominant behavior. Research was conducted in the Wadden Sea, an acoustically complex, tidally driven habitat with high particle resuspension. Source levels and echolocation parameters of wild harbor porpoises were estimated from time-of-arrival-differences of a six-element hydrophone array. The back-calculated peak-to-peak apparent source level of 169 ± 5 dB re 1 µPa was significantly lower than reported from Inner Danish Waters (-20 dB) and British Columbia (-9 dB) with narrower bandwidth. Porpoises therefore reduce their source level in the Wadden Sea under acoustically complex conditions suggesting an avoidance of cluttering.

Fatty Acid Composition in Blubber, Liver, and Muscle of Marine Mammals in the Southern Baltic Sea.

To date, only limited results on the fatty composition in different tissues of the top predators in the Baltic Sea are available. In the current study, tissue samples of blubber, skeletal muscle, and liver from 8 harbour porpoise (Phocoena phocoena) and 17 grey seals (Halichoerus grypus) in the Baltic Sea off Mecklenburg-Western Pomerania were included in the investigation. While the total fatty acid content in liver and blubber tissue revealed no differences between both species, the total fatty acid content of muscle tissue was significantly differentand showed higher concentrations in harbour porpoise muscle compared with grey seals. The most abundant fatty acids in the blubber of grey seals and harbour porpoises (18:1cis-9, 16:1cis-9, 16:0 and 22:6n-3) were present in similar quantities and ratios to each other as known from other marine top predators. If future studies can show that differences in tissue fatty acid content are caused by variation in the nutritional status, and this may lead to the development of a more objective assessment of body condition in seals and porpoises recovered via stranding schemes.

Pathological findings in North Sea and Baltic grey seal and harbour seal intestines associated with acanthocephalan infections.

Grey seals Halichoerus grypus and harbour seals Phoca vitulina are common seal species in the North and Baltic seas and final hosts of Corynosoma acanthocephalans. C. strumosum and C. magdaleni infect the small intestines of both seal species. In contrast to harbour seals, Baltic grey seals in the past have regularly displayed severe C. semerme infections in the caecum and colon, with associated tunica muscularis hypertrophy, inflammation and ulcerations as part of the Baltic seal disease complex (BSDC). Pathogenesis and correlation of acanthocephalan infections with these lesions are still unknown. This study describes the intestinal pathology and parasitic distribution in each seal species. Grey seal (n = 83) and harbour seal (n = 1156) intestines of all age groups and sexes, collected in Poland, Germany and Estonia from 1998 to 2017, were investigated. Most harbour seals came from the North Sea, whereas grey seals were predominantly derived from the Baltic Sea. Both species featured mild to moderate small intestinal infections. Grey seals showed colonic infections not found in harbour seals and featured a chronic erosive to ulcerative, eosinophilic or lympho-plasmacytic colitis with tunica muscularis hypertrophy, indicating still prevailing clinical signs of the BSDC. Harbour seals displayed granulomatous, eosinophilic, lympho-plasmacytic or catarrhal enteritis. The prevalence of acanthocephalan infections in harbour seals increased from 2012 onwards. Furthermore, significant associations between acanthocephalan infection and the presence of intestinal inflammation were found for both seal species. This study suggests that the level of acanthocephalan infection and associated lesions are suitable seal population health indicators, with the colon being a specific target organ for Baltic grey seal health monitoring.

Individual Effector/Regulator T Cell Ratios Impact Bone Regeneration.

There is increasing evidence that T lymphocytes play a key role in controlling endogenous regeneration. Regeneration appears to be impaired in case of local accumulation of CD8+ effector T cells (TEFF), impairing endogenous regeneration by increasing a primary "useful" inflammation toward a damaging level. Thus, rescuing regeneration by regulating the heightened pro-inflammatory reaction employing regulatory CD4+ T (TReg) cells could represent an immunomodulatory option to enhance healing. Hypothesis was that CD4+ TReg might counteract undesired effects of CD8+ TEFF. Using adoptive TReg transfer, bone healing was consistently improved in mice possessing an inexperienced immune system with low amounts of CD8+ TEFF. In contrast, mice with an experienced immune system (high amounts of CD8+ TEFF) showed heterogeneous bone repair with regeneration being dependent upon the individual TEFF/TReg ratio. Thus, the healing outcome can only be improved by an adoptive TReg therapy, if an unfavorable TEFF/TReg ratio can be reshaped; if the individual CD8+ TEFF percentage, which is dependent on the individual immune experience can be changed toward a favorable ratio by the TReg transfer. Remarkably, also in patients with impaired fracture healing the TEFF/TReg ratio was higher compared to uneventful healers, validating our finding in the mouse osteotomy model. Our data demonstrate for the first time the key-role of a balanced TEFF/TReg response following injury needed to reach successful regeneration using bone as a model system. Considering this strategy, novel opportunities for immunotherapy in patients, which are at risk for impaired healing by targeting TEFF cells and supporting TReg cells to enhance healing are possible.

Time and tide: Seasonal, diel and tidal rhythms in Wadden Sea Harbour porpoises (Phocoena phocoena).

Odontocetes have evolved a rich diversity of prey- and habitat-specific foraging strategies, which allows them to feed opportunistically on locally and temporally abundant prey. While habitat-specific foraging strategies have been documented for some odontocete species, this is less known for the harbour porpoise (Phocoena phocoena). We collected multiple years of acoustic data using echolocation click loggers to analyse porpoise occurrence and buzzing behaviour, indicating feeding, in the German Wadden Sea (North Sea). Seasonal, diel and tidal effects were studied using Generalised Estimating Equations (GEE-GAMs). Locally season, time of day and tidal time significantly influenced the probability of porpoise detections and detection of foraging sequences (buzzes). Hunting strategies, and therefore frequency of buzzes, were likely affected by prey distribution and large differences between POD locations indicated that porpoises used highly specific behaviour adapted to tide and time of day to efficiently feed on the available prey. Strong seasonal and spatial variation in diel and tidal effects underline the importance of long-term observations. Studies on porpoise behaviour are often based on short-term observations and might rather reflect a seasonal than a general pattern. The results of this study show clearly that significant changes in porpoise behaviour can be found in short and long-term observations. Here some features are based on short term determinants and others are stable over years and care should be taken about drawing general conclusions based on local patterns. Highly variable spatio-temporal patterns indicate a high flexibility of porpoises in a highly variable environment and address a challenge for complex conservation management plans.

Why is auditory frequency weighting so important in regulation of underwater noise?

A key question related to regulating noise from pile driving, air guns, and sonars is how to take into account the hearing abilities of different animals by means of auditory frequency weighting. Recordings of pile driving sounds, both in the presence and absence of a bubble curtain, were evaluated against recent thresholds for temporary threshold shift (TTS) for harbor porpoises by means of four different weighting functions. The assessed effectivity, expressed as time until TTS, depended strongly on choice of weighting function: 2 orders of magnitude larger for an audiogram-weighted TTS criterion relative to an unweighted criterion, highlighting the importance of selecting the right frequency weighting.

Assessing auditory evoked potentials of wild harbor porpoises (Phocoena phocoena).

Testing the hearing abilities of marine mammals under water is a challenging task. Sample sizes are usually low, thus limiting the ability to generalize findings of susceptibility towards noise influences. A method to measure harbor porpoise hearing thresholds in situ in outdoor conditions using auditory steady state responses of the brainstem was developed and tested. The method was used on 15 live-stranded animals from the North Sea during rehabilitation, shortly before release into the wild, and on 12 wild animals incidentally caught in pound nets in Denmark (inner Danish waters). Results indicated that although the variability between individuals is wide, the shape of the hearing curve is generally similar to previously published results from behavioral trials. Using 10-kHz frequency intervals between 10 and 160 kHz, best hearing was found between 120 and 130 kHz. Additional testing using one-third octave frequency intervals (from 16 to 160 kHz) allowed for a much faster hearing assessment, but eliminated the fine scale threshold characteristics. For further investigations, the method will be used to better understand the factors influencing sensitivity differences across individuals and to establish population-level parameters describing hearing abilities of harbor porpoises.

Impacts of Underwater Noise on Marine Vertebrates: Project Introduction and First Results.

The project conducts application-oriented research on impacts of underwater noise on marine vertebrates in the North and Baltic Seas. In distinct subprojects, the hearing sensitivity of harbor porpoises and gray seals as well as the acoustic tolerance limit of harbor porpoises to impulsive noise from pile driving and stress reactions caused by anthropogenic noise is investigated. Animals are equipped with DTAGs capable of recording the actual surrounding noise field of free-swimming harbor porpoises and seals. Acoustic noise mapping including porpoise detectors in the Natura 2000 sites of the North and Baltic Seas will help to fully understand current noise impacts.

Development of a Model to Assess Masking Potential for Marine Mammals by the Use of Air Guns in Antarctic Waters.

We estimated the long-range effects of air gun array noise on marine mammal communication ranges in the Southern Ocean. Air gun impulses are subject to significant distortion during propagation, potentially resulting in a quasi-continuous sound. Propagation modeling to estimate the received waveform was conducted. A leaky integrator was used as a hearing model to assess communication masking in three species due to intermittent/continuous air gun sounds. Air gun noise is most probably changing from impulse to continuous noise between 1,000 and 2,000 km from the source, leading to a reduced communication range for, e.g., blue and fin whales up to 2,000 km from the source.

In-air evoked potential audiometry of grey seals (Halichoerus grypus) from the North and Baltic Seas.

In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1-20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4-20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal.