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Abstract The high incidence of deep vein thrombosis (DVT) in evacuees has been recognized since the 2004 Niigata-Chuetsu Earthquake in Japan. We hypothesized that the number and location of communicating branches of the soleal veins might influence thrombus development and that the median septum of the soleus muscle influences the venous network of the soleal veins. This study aimed to investigate how the network of soleal veins varies with the shape and thickness of the median septum and to elucidate factors predisposing soleal veins to DVT. The lower legs of 30 sides from 15 formalin-preserved cadavers were observed. The central soleal vein, the predilection site for thrombus among the six veins within the soleus muscle, divides into three branches: medial, central, and lateral. The soleus muscle has a unique architecture with converging muscle fibers on the anterior surface of the median septum. We examined the positional relationship between the central soleal vein and the median septum. The median septum morphology was either straight (14 sides, 46.7%) or curved (16 sides, 53.3%). The number of communicating branches was significantly higher in the curved type. The curved type also had a communicating vein penetrating the median septum, with the central branch passing deeper than in the straight type. The median septum could restrict the enlargement of communicating branches, causing thrombosis through disturbance of venous blood flow. Future research will clarify the median septum’s influence on the soleal vein, potentially identifying soleus muscles at high risk of developing DVT.

The state of California, USA, has developed regulations for projects that want to pursue direct potable reuse. One of the most significant requirements is that the treatment train must include ozone and biological activated carbon (ozone/BAC) as pretreatment to a membrane-based treatment train. Ozone/BAC mitigates chemical peaks and diversifies the removal mechanisms of low molecular weight compounds likely to persist in advanced treated water. This paper will present the process benefits of ozone/BAC as pretreatment to the membrane-based treatment train based on testing at a 3,785 m3/d demonstration facility in San Diego, California, USA. One of the most significant benefits of ozone/BAC pretreatment is the improved water quality that benefits not only the product water produced for potable consumption but also the residual stream that is generated with the implementation of the RO process, commonly known as RO concentrate. This improved water quality originates from TOC reduction which is achieved through a combination of chemical oxidation with ozonation and biological growth in the BAC process that results in reduced operating pressures and chemical use for the membrane systems. These process benefits were quantified to develop an overall water cost comparison between a DPR and an indirect potable reuse train. HIGHLIGHTS Benefits of O3/BAC for potable reuse are substantial but underappreciated.; O3/BAC-MF-RO-UV/AOP treatment train provides a greater degree of public health protection.; The experimental DPR treatment train operated at lower O&M costs compared to FAT.; Benefits were quantified for a 30-year basis and show that this train has a similar cost despite higher CAPEX.; O3/BAC-based DPR treatment trains are economically viable.;

Properties of the nuclear equation of state (EoS) can be probed by measuring the dynamical properties of nucleus-nucleus collisions. In this study, we present the directed flow (v1), elliptic flow (v2) and stopping (VarXZ) measured in fixed target Sn + Sn collisions at Image 1 with the SπRIT Time Projection Chamber. We perform Bayesian analyses in which EoS parameters are varied simultaneously within the Improved Quantum Molecular Dynamics-Skyrme (ImQMD-Sky) transport code to obtain a multivariate correlated constraint. The varied parameters include symmetry energy, S0, and slope of the symmetry energy, L, at saturation density, isoscalar effective mass, ms⁎/mN, isovector effective mass, mv⁎/mN and the in-medium cross-section enhancement factor η. We find that the flow and VarXZ observables are sensitive to the splitting of proton and neutron effective masses and the in-medium cross-section. Comparisons of ImQMD-Sky predictions to the SπRIT data suggest a narrow range of preferred values for ms⁎/mN, mv⁎/mN and η.

Background: This report aims to supplement the existing knowledge on the inferior oblique muscle. In particular, this study presents detailed anatomical and histological data concerning the muscle’s entry point (or entry zone) of the nerve to the inferior oblique muscle. Particular attention was paid to the topographical relationships of the nerve to the inferior oblique muscle (NTIO), including the location of its entry point to the muscle’s belly and its anatomical variations. Methods: Sixty orbits from cadaveric hemi-heads fixed in 10% formalin were studied. The course of the NTIO was traced along the lateral border of the inferior rectus muscle as far as its entry point to the inferior oblique muscle. Particular attention was paid to the various ways in which the NTIO’s muscular sub-branches penetrated between the fibers of the inferior oblique muscle. Results: Three types of NTIO entries to the inferior oblique muscle’s belly were distinguished. In the most common type (48.3%), the nerve entered the muscle’s inferior (orbital) surface. In the next most common type (36.7%), terminal muscular sub-branches of the NTIO joined the superior (also referred to as ocular or global) surface of the inferior oblique muscle. In the remaining four cases (15%), the terminal sub-branches of the NTIO were divided into two main groups (superior and inferior) that joined both the superior and inferior surfaces of the muscle. Histological examination confirmed that the distal part of the NTIO shows a characteristic arcuate course (angulation) just before reaching the muscle’s belly. The process for splitting and forming separate muscular sub-branches of the NTIO was observed for all the examined histological specimens at the level of the nerve’s angulation. Conclusions: The presented findings enhance the understanding of the anatomical variations and precise distribution of motor sub-branches reaching the inferior oblique muscle, which may deepen anatomical knowledge and potentially enhance the management of ocular motor disorders.

This study consists of a retrospective cohort study, a systematic review, and a meta-analysis which were separately conducted. This study aimed to investigate the prevalence of atlas arch defects, generate an evidence-based synthesis, and propose a common classification system for the anterior and combined atlas arch defects. Atlas arch defects are well-corticated gaps in the anterior or posterior arch of the atlas. When both arches are involved, it is known as a combined arch defect. Awareness of these defects is essential for avoiding complications during surgical procedures on the upper spine. The prevalence of arch defects was investigated in an open-access OPC-Radiomics (Radiomic Biomarkers in Oropharyngeal Carcinoma) dataset comprising 606 head and neck computed tomography scans from oropharyngeal cancer patients. A systematic review and meta-analysis were performed to generate prevalence estimates of atlas arch defects and propose a classification system for the anterior and combined atlas arch defects. The posterior arch defect was found in 20 patients (3.3%) out of the 606 patients investigated. The anterior arch defect was not observed in any patient, while a combined arch defect was observed in one patient (0.2%). A meta-analysis of 13,539 participants from 14 studies, including the present study, yielded a pooled-posterior arch defect prevalence of 2.07% (95% confidence interval [CI], 1.22%–2.92%). The prevalences of anterior and combined arch defects were 0.00% (95% CI, 0.00%–0.10%) and 0.14% (95% CI, 0.04%–0.25%), respectively. The anterior and combined arch defects were classified into five subtypes based on their morphology and frequency. The present study showed that atlas arch defects were present in approximately 2% of the general population. For future studies, larger sample sizes should be used for studying arch defects to avoid the small-study effect and to predict the prevalence accurately.

ABSTRACTMicrobial communities have evolved to colonize all ecosystems of the planet, from the deep sea to the human gut. Microbes survive by sensing, responding, and adapting to immediate environmental cues. This process is driven by signal transduction proteins such as histidine kinases, which use their sensing domains to bind or otherwise detect environmental cues and “transduce” signals to adjust internal processes. We hypothesized that an ecosystem’s unique stimuli leave a sensor “fingerprint,” able to identify and shed insight on ecosystem conditions. To test this, we collected 20,712 publicly available metagenomes from Host-associated, Environmental, and Engineered ecosystems across the globe. We extracted and clustered the collection’s nearly 18M unique sensory domains into 113,712 similar groupings with MMseqs2. We built gradient-boosted decision tree machine learning models and found we could classify the ecosystem type (accuracy: 87%) and predict the levels of different physical parameters (R2 score: 83%) using the sensor cluster abundance as features. Feature importance enables identification of the most predictive sensors to differentiate between ecosystems which can lead to mechanistic interpretations if the sensor domains are well annotated. To demonstrate this, a machine learning model was trained to predict patient’s disease state and used to identify domains related to oxygen sensing present in a healthy gut but missing in patients with abnormal conditions. Moreover, since 98.7% of identified sensor domains are uncharacterized, importance ranking can be used to prioritize sensors to determine what ecosystem function they may be sensing. Furthermore, these new predictive sensors can function as targets for novel sensor engineering with applications in biotechnology, ecosystem maintenance, and medicine.IMPORTANCEMicrobes infect, colonize, and proliferate due to their ability to sense and respond quickly to their surroundings. In this research, we extract the sensory proteins from a diverse range of environmental, engineered, and host-associated metagenomes. We trained machine learning classifiers using sensors as features such that it is possible to predict the ecosystem for a metagenome from its sensor profile. We use the optimized model’s feature importance to identify the most impactful and predictive sensors in different environments. We next use the sensor profile from human gut metagenomes to classify their disease states and explore which sensors can explain differences between diseases. The sensors most predictive of environmental labels here, most of which correspond to uncharacterized proteins, are a useful starting point for the discovery of important environment signals and the development of possible diagnostic interventions.

Background/purpose: A Stafne bone cavity (SBC) is an incidental depression in the lingual surface of the mandible. The aim of this study is to provide pooled estimates of the frequency of Stafne bone cavity and to correlate its presence with such variables as sex, laterality, diagnostic methods and population. Materials and methods: Potential studies were searched through four electronic databases: Google Scholar, PubMed, Scopus, and Journal Storage. Titles, abstracts, and full texts of the articles were screened. Results: A total of 54 studies relating to 355,890 subjects met the inclusion criteria for meta-analysis. A meta-analysis using the DerSimonian-Laird model revealed an overall prevalence of 0.17% (CI:0.14%–0.21%, I2 = 80.7%). SBC was four times more common in males than females (z = 6.94, P

Total hip arthroplasty is a widely performed operation allowing disabled patients to improve their quality of life to a degree greater than any other elective procedure. Planning for a THA requires adequate patient assessment and preoperative characterizations of acetabular bone loss via radiographs and specific classification schemes. Some surgeons may be inclined to ream at a larger diameter thinking it would lead to a more stable press-fit, but this could be detrimental to the acetabular wall, leading to intraoperative fracture. In the attempt to reduce the incidence of intraoperative fractures, the current study aims to identify how increased reaming diameter degrades and weakens the acetabular rim strength. We hypothesized that there is proportionality between the reaming diameter and the reduction in acetabular strength. To test this hypothesis, this study used bone surrogates, templated from CT scans, and reamed at different diameters. The obtained bone surrogate models were then tested using an Intron 8874 mechanical testing machine (Instron, Norwood, MA) equipped with a custom-made fixture. Analysis of variance (ANOVA) was used to identify differences among reamed diameters while linear regression was used to identify the relationship between reamed diameters and acetabular strength. We found a moderate correlation between increasing reaming diameter that induced thinning of the acetabular wall and radial load damage. For the simplified acetabular model used in this study, it supported our hypothesis and is a promising first attempt in providing quantitative data for acetabular weakening induced by reaming.

Abstract Background Distal first metatarsal osteotomy is used to correct mild or moderate hallux valgus (HV). We designed a cadaveric study to compare the resistance to axial load between two percutaneous distal first metatarsal osteotomies: Bösch osteotomy and percutaneous chevron. The first aim of this study was to develop a systematic technique for measuring the sagittal displacement on lateral foot X-rays. Our second objective was to measure the resistance to axial load for both of these osteotomies. Methods Ten pairs of freshly frozen cadaveric feet were randomly assigned to one of the two techniques investigated. Pre- and post-operative lateral X-rays were obtained. After surgery, the feet were placed under progressive axial loads up to 60 kg. Metaphyseo-diaphyseal angle (MDA) and the distance between bone fragments were measured, and the differences between the two techniques were statistically assessed. Results The MDA decreased in both surgical techniques. The mean plantar tilt was −6.90 degrees (SD = 10.251) for chevron osteotomy and −5.34 degrees (SD = 16.621) for Bösch osteotomy. There was no significant difference between the techniques (p = 0.41). Regarding the distance between the bone fragments, the Bösch osteotomy produced more plantar displacement than the chevron osteotomy, which was statistically significant for the 10 and 20 kg loads (p = 0.031 and 0.04, respectively). At loads ≥ 30 kg, the bone fragment distance did not differ significantly between the techniques (p = 0.114). Conclusions Although the chevron technique confers higher stability regarding fragment displacement during axial loading, both techniques increase the plantar angulation of the metatarsal head. Level of evidence Cadaveric study. Level V.

BackgroundThis study aimed to determine the patterns of invasion of oral squamous cell carcinoma (OSCC) into the bucco-mandibular space (BMS) using detailed histopathological analysis and to assess clinical outcomes.MethodsPatients with OSCC who underwent segmental mandibulectomy or hemi-mandibulectomy combined with resection of the BMS between 2012 and 2021 were included. The invasions of the BMS were classified into three patterns. Pattern A was defined as a horizontal invasion, Pattern B as a vertical invasion, and Pattern C as an expansive invasion.ResultsIn total, 109 patients were reviewed. Of these 109 patients, the primary tumor affected the lower gingiva in 78 patients, the buccal mucosa in 18 patients, and was a primary intraosseous carcinoma of the mandible in 13 patients. Invasion of the BMS was significantly associated with a higher pathological T stage, positive/close margins, and lower disease-free survival (DFS) rates. The DFS rates were 86.7% and 66.0% in the BMS non-invasion and invasion groups, respectively. The DFS rates for each type of invasion were 82.1% for Pattern A, 67.4% for Pattern B, and 48.0% for Pattern C (P=0.277).ConclusionPatients with BMS invasion have a poorer prognosis than those without invasion of the BMS. Therefore, adjuvant therapy is necessary, especially in Patterns B and C. Evaluation of preoperative BMS invasion patterns is important for predicting the prognosis of OSCC.

Abstract Painful lesions on the plantar aspect of the first interphalangeal joint (IPJ) of the hallux can be attributed to structures called ossicles, nodules, or sesamoids. The aims of the present study were first to verify that ultrasonography (US) is a high-sensitivity tool for diagnosing an interphalangeal ossicle (IO), and second to prove that US-guided-shaving surgery (“milling”) is a safe and feasible technique for remodeling the IO. The study is divided into three parts. In the first part, the prevalence of IOs was estimated in 12 cadaver feet using US, anatomical dissection, and fluoroscopy. In the second, a detailed US and morphological description of the IO was obtained. In the third, six cadaver feet were subjected to surgical milling. IO prevalence was 41.6% in gross anatomy, 41.6% in US examination and just 16.6% in fluoroscopy. The ossicles had a mean length of 4 mm (± 2 mm) and a width of 7 mm (± 2 mm). The ossicles could be completely shaved in all specimens without injuring important anatomical structures. Our results indicate that US is a more precise tool for diagnosing an IO than X-ray. Moreover, our US-guided mini-invasive surgical technique appears feasible and safe.

Neurovascular compression syndromes (NVC) are challenging disorders resulting from the compression of cranial nerves at the root entry/exit zone. Clinically, we can distinguish the following NVC conditions: trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia. Also, rare cases of geniculate neuralgia and superior laryngeal neuralgia are reported. Other syndromes, e.g., disabling positional vertigo, arterial hypertension in the course of NVC at the CN IX-X REZ and torticollis, have insufficient clinical evidence for microvascular decompression. The exact pathomechanism leading to characteristic NVC-related symptoms remains unclear. Proposed etiologies have limited explanatory scope. Therefore, we have examined the underlying pathomechanisms stated in the medical literature. To achieve our goal, we systematically reviewed original English language papers available in Pubmed and Web of Science databases before 2 October 2021. We obtained 1694 papers after eliminating duplicates. Only 357 original papers potentially pertaining to the pathogenesis of NVC were enrolled in full-text assessment for eligibility. Of these, 63 were included in the final analysis. The systematic review suggests that the anatomical and/or hemodynamical changes described are insufficient to account for NVC-related symptoms by themselves. They must coexist with additional changes such as factors associated with the affected nerve (e.g., demyelination, REZ modeling, vasculature pathology), nucleus hyperexcitability, white and/or gray matter changes in the brain, or disturbances in ion channels. Moreover, the effects of inflammatory background, altered proteome, and biochemical parameters on symptomatic NVC cannot be ignored. Further studies are needed to gain better insight into NVC pathophysiology.

In humans, the incidence of congenital defects of the intraembryonic celom and its associated structures has increased over recent decades. Surgical treatment of abdominal and diaphragmatic malformations resulting in congenital hernia requires deep knowledge of ventral body closure and the separation of the primary body cavities during embryogenesis. The correct development of both structures requires the coordinated and fine-tuned synergy of different anlagen, including a set of molecules governing those processes. They have mainly been investigated in a range of vertebrate species (e.g., mouse, birds, and fish), but studies of embryogenesis in humans are rather rare because samples are seldom available. Therefore, we have to deal with a large body of conflicting data concerning the formation of the abdominal wall and the etiology of diaphragmatic defects. This review summarizes the current state of knowledge and focuses on the histological and molecular events leading to the establishment of the abdominal and thoracic cavities in several vertebrate species. In chronological order, we start with the onset of gastrulation, continue with the establishment of the three-dimensional body shape, and end with the partition of body cavities. We also discuss well-known human etiologies.

Background: Although Meckel's diverticulum is a well-known variation, there is rarely an opportunity to trace the detailed anatomy of this structure in dissection material with resin-injected arteries, especially in fetuses. This report presents a detailed description of the ileal diverticulum found in a human fetus, including its vascularization and relationship to the mesentery. Case description: A persistent and well-developed Meckel's diverticulum was found during dissection of a female fetus (CRL = 19 cm). The diverticulum was located in the distal portion of the ileum, among the small intestine loops, and occupied the antimesenteric border of the intestine. It had a broad base and narrowed towards the end; its end was free. Since the arteries were injected with red resin, nutrient branches to the diverticulum from the ileal arteries could be traced in detail. Conclusions: Anatomically, diverse variants of Meckel's diverticulum can occur. The diverticulum can have its own mesentery, and its primary blood supply is from the remnant vitelline artery.

Introduction: The petrosphenoidal ligament (also termed as petroclival ligament) was described in 1859 by Wenzel Gruber, a Russian anatomist. Hence, the popular eponym of Gruber's ligament. Typically, the petrosphenoidal ligament is stretched between the petrous apex and in the vicinity of the posterior clinoid process, forming the posteromedial wall of the Dorello's canal located within the inferomedial paraclival triangle. This report presents a previously unreported attachment of the petrosphenoidal ligament to the posterior genu of the cavernous internal carotid artery. Since the ligament can be a helpful landmark during neurosurgical procedures, our report might have practical value. Case description: During routine dissection of the isolated sagittal section of the head from a male cadaver, an atypical attachment of the petrosphenoidal (petroclival) ligament was observed. The proximal ligament's attachment was bifid. Some ligament bundles originated from the lateral aspect of the clivus, while another group of bundles originated from the posteromedial aspect of the posterior genu of the cavernous internal carotid artery. The ligament had a triangular shape with a broader distal attachment to the petrous apex. The meningohypophysial trunk was in juxtaposition to the arterial attachment of the ligament. It was noted that the arterial attachment was well-fixed to the internal carotid artery's adventitia. Conclusions: The dual origin of the petrosphenoidal ligament to the clivus and internal carotid artery's posterior genu causes atypical fixation of both structures. It can potentially alter selected surgical procedures, such as mobilization of the internal carotid artery's short vertical segment and posterior genu.

Purpose: To evaluate Workers’ Compensation (WC) patients who underwent arthroscopic shoulder surgery for workplace shoulder injuries and to determine whether there was an association between earlier return to light duty and earlier return to full duty. Methods: After receiving institutional review board approval, we performed a retrospective chart review of all WC patients treated with shoulder arthroscopic surgery by 2 senior authors between 2011 and 2018. The patients were divided into 2 groups: Group 1 went back to light-duty work within the first 100 days after surgery, whereas group 2 performed light-duty work after 100 days or performed no light-duty work. The primary outcomes included the length of time from surgery to light-duty work and the length of time from surgery to return to the full-duty work level. Results: A total of 59 patients met the inclusion criteria. There was a moderate correlation between the number of days at which the patients were released to light duty and the days they were able to be released to full duty (r = 0.35). In group 1 (light duty ≤ 100 days), 18 patients (75%) went back to full duty, whereas only 16 patients (46%) in group 2 were able to return to full-duty work (P = .025). Conclusions: Earlier return to light duty is associated with earlier return to full duty after shoulder arthroscopic surgery in patients with a Workers’ Compensation claim. Additionally, WC patients who returned to early light duty in the first 100 days postoperatively had a higher rate of return to full duty than did patients who did not return to early light duty. Level of Evidence: Level III, case-control study.

Background: The profunda brachii artery (PBA), also known as the deep brachial artery or deep artery of the arm, is one of the principal branches of the brachial artery. Typically The PBA accompanies the radial nerve in the posterior compartment of the arm. Both the PBA and radial nerve pass backward through the triangular interval of the arm and enter the radial sulcus. Since there are few studies on the anatomy of the PBA, the data on its course and branching pattern have remained unchanged for years. However, everyday clinical practice shows that anatomical variability is common, so a detailed description of the divergences from the most typical morphology is needed. Methods: In this report, three different anatomical variants of the course and division of the PBA were described, including a detailed description of its topographical relationships especially with the radial nerve. Results: Case No. 1 involves a variant of the PBA in which both terminal branches of the artery take separate origins directly from the posterior aspect of the brachial artery. Case No. 2 presents a variant in which both terminal branches of the artery have a very distal origin. Case No. 3 is a variant in which the PBA crosses the radial nerve's posterior aspect. Conclusions: Variations of the PBA and its terminal branches should be considered in planning and conducting orthopedic, plastic, and reconstructive surgeries.

Background: The ulnar collateral ligament (UCL) complex of the elbow plays a primary role in valgus and posteromedial stability of the elbow. The anterior oblique ligament (AOL) of the UCL is believed to provide the majority of resistance to external forces on the medial elbow. The transverse ligament (TL) of the UCL is generally thought to have minimal contribution to the elbow’s overall stability. However, recent studies have suggested a more significant role for the TL. The primary aim of this study was to identify the TL’s contribution to the stability of the elbow joint in determining the joint stiffness and neutral zone variation in internal rotation. Methods: Twelve cadaveric elbows, set at a 90° flexion angle, were tested by applying an internal rotational force on the humerus to generate a medial opening torque at the level of the elbow. The specimens were preconditioned with 10 cycles of humeral internal rotation with sinusoidal torque ranging from 0 to 5 Nm. Elbow stiffness measures and joint neutral zone were first evaluated in its integrity during a final ramp loading. The test was subsequently repeated after cutting the TL at 33%, 66%, and 100% followed by the AOL in the same fashion. Results: The native UCL complex joint stiffness to internal rotation measured 1.52 ± 0.51 Nm/°. The first observable change occurred with 33% sectioning of the AOL, with further sectioning of the AOL minimizing the joint stiffness to 1.26 ± 0.32 Nm/° (P = .004). A 33% resection of the TL found an initial neutral zone variation of 0.376 ± 0.23° that increased to 0.771 ± 0.41° (P

Background and Objectives: Anatomical variations in the head, neck and chest are common, and are observed as occasional findings on computed tomography (CT). Although anatomical variations are mostly asymptomatic and do not cause any negative influence on the body function, they may jeopardize diagnosis and may be confused with pathological conditions. The presence of variations may also limit surgical access during tumor removal. The aim of this study was to investigate the prevalence of six anatomical variations—os acromiale, episternal ossicles, cervical rib, Stafne bone cavity, azygos lobe and tracheal bronchus—in an open-access computed tomography dataset obtained from oropharyngeal cancer patients. Materials and Methods: A total of 606 upper-chest and neck computed-tomography scans (79.4% male and 20.6% female) were retrospectively investigated. Sex difference was evaluated using the z-test for two proportions. Results: Os acromiale, episternal ossicles, cervical rib, Stafne bone cavity, azygos lobe, and tracheal bronchus were present in 3.1%, 2.2%, 0.2%, 0%, 0.3% and 0.5%, respectively, of all patients. Os acromiale was identified as meso-acromion in 86.6%, and as pre-acromion in 17.4%, of all acromia. Episternal ossicles were present unilaterally in 58.3%, and bilaterally in 41.7%, of all sterna. Only the cervical rib showed a sex difference in prevalence. Conclusions: awareness of these variations is important for radiologists interpreting head, neck and chest CTs; for example, those of oropharyngeal cancer patients. This study also illustrates the applicability of publicly available datasets in prevalence-based anatomical research. While most of the variations investigated in the present study are well-known, the episternal ossicles are not well explored, and need further investigation.

Abstract There are countless morphological variations among the muscles, tendons, ligaments, arteries, veins and nerves of the human body, many of which remain undescribed. Anatomical structures are also subject to evolution, many disappearing and others continually emerging. The main goal of this pilot study was to describe a previously undetected anatomical structure, the plantaris ligamentous tendon, and to determine its frequency and histology. Twenty-two lower limbs from 11 adult cadavers (11 left, and 11 right) fixed in 10% formalin were examined. The mean age of the cadavers at death was 60.1 years (range 38–85). The group comprised six women and five men from a Central European population. All anatomical dissections of the leg and foot area accorded with the pre-established protocol. Among the 22 lower limbs, the PLT was present in 16 (72.7%) and absent in six (27.3%). It originated as a strong fan-shaped ligamentous tendon from the superior part of the plantaris muscle, the posterior surface of the femur and the lateral aspect of the knee joint capsule. It inserted to the ilio-tibial band. Histologically, a tendon and ligament were observed extending parallel to each other. A new anatomical structure has been found, for which the name plantaris ligamentous tendon is proposed. It occurs around the popliteal region between the plantaris muscle, the posterior surface of the femur, and the ilio-tibial band.

Purpose: The aim of this review is to reflect on the question of gross anatomical normality and variability. Particular attention has been paid to what is considered normal in gross anatomy and the premises for recognizing a given structure as normal. The earliest historical sources referring to anatomical variations are described in the paper. The general significance of anatomical variations is also discussed. Results: Having established and classified the laws of nature, scientists gradually achieved the skill of judging what is most typical and what is rare or deviates from the commonly-observed pattern. Normality in anatomy can be considered relative (linked to a specific set of assumptions) and is inferred from numerous repeated observations. In anatomy textbooks, the term “norm” is associated with such concepts as general pattern, rule, or canon. Deviations from the most common (assumed to be typical) morphology are described as variants or types of organs or anatomical structures. The term “anomaly” is also used in the anatomical and medical literature to describe variations; however, this designation can also be applied to pathological conditions. Nevertheless, the “norm” in anatomy is not as precise a concept as one would wish, and can be considered an approximation. In fact, anatomical variability is the rule, though most variations are within the normal range. Thus, the idea of a medical and anatomical norm is analogous the sorites paradox because the boundaries between what is considered normal and what is anomalous are blurred. Nevertheless, the anatomical norm should only be regarded as an idealized scientific model; anatomical variations should be kept in mind in clinical practice. Conclusions: “Anatomical norm” can be considered on the one hand as a useful reference point for clinicians and on the other as an idealized scientific model.

Background:. Radiation exposure of orthopaedic residents should be accurately monitored to monitor and mitigate risk. The purpose of this study was to determine whether a personalized lead protocol (PLP) with a radiation monitoring officer would improve radiation exposure monitoring of orthopaedic surgery residents. Materials and Methods:. This was a retrospective case-control study of 15 orthopaedic surgery residents monitored for radiation exposure during a 2-year period (March 2017 until February 2019). During the first 12-month period (phase 1), residents were given monthly radiation dosimeter badges and instructed to attach them daily to the communal lead aprons hanging outside the operating rooms. During the second 12-month period (phase 2), a PLP (PLP group) was instituted in which residents were given lead aprons embroidered with their individual names. A radiation safety officer was appointed who placed the badges monthly on all lead aprons and collected them at the end of the month, whereas faculty ensured residents wore their personalized lead apron. Data collected included fluoroscopy use time and radiation dosimeter readings during all orthopaedic surgeries in the study period. Results:. There were 1,252 orthopaedic surgeries using fluoroscopy during phase 1 in the control group and 1,269 during phase 2 in the PLP group. The total monthly fluoroscopy exposure time for all cases averaged 190 minutes during phase 1 and 169 minutes during phase 2, with no significant difference between the groups (p < 0.45). During phase 1, 73.1% of the dosimeters reported radiation exposure, whereas during phase 2, 88.7% of the dosimeters reported radiation exposure (p < 0.001). During phase 1, the average monthly resident dosimeter exposure reading was 7.26 millirems (mrem) ± 37.07, vs. 19.00 mrem ± 51.16 during phase 2, which was significantly higher (p < 0.036). Conclusions:. Institution of a PLP increased the compliance and exposure readings of radiation dosimeter badges for orthopaedic surgery residents, whereas the actual monthly fluoroscopy time did not change. Teaching hospitals should consider implementing a PLP to more accurately monitor exposure. Level of Evidence:. 3.

We report a rare case of concomitant abdominal aortic aneurysm (AAA) and left renal cell carcinoma (RCC). The patient was an 81-year old man who presented with vague abdominal pain. The investigations revealed a 110*73*62 mm AAA together with 69*56 left renal mass. Open repair of AAA with left radical nephrectomy was conducted. A simultaneous procedure is safe and does not increase morbidity and mortality in selected cases.

Objectives The aim of this study was to elucidate the positional relationship between the courses of the angular veins and the facial muscles, and the possible roles of the latter as alternative venous valves. Methods The angular veins of 44 specimens of embalmed Korean adult cadavers were examined. Facial muscles were studied to establish their relationships with the angular vein, including the orbicularis oculi (OOc), depressor supercilii (DS), zygomaticus minor (Zmi), zygomaticus major (Zmj), and levator labii superioris (LLS). Results In the upper face of all specimens, the angular vein passed through the DS and descended to the medial palpebral ligament. In the midface, it passed between the origin of the levator labii superioris alaeque nasi (LLSAN) and the inferior OOc fibers. The vein coursed along the deep surface of the inferior margin of the OOc in all specimens. At the level of the nasal ala, the course of the angular vein was classified into three types: in type I it passed between the LLS and Zmi (38.6%), in type II it passed between the superficial and deep fibers of the Zmi (47.7%), and in type III it passed between the Zmi and Zmj (13.6%). In the lower face of all specimens, the angular or facial vein passed through the anterior lobe of the buccal fat pad. Conclusion This study found that the angular vein coursed along the sites where facial muscle contractions are assumed to efficiently compress the veins, likely controlling venous flow as valves. The observations made and analysis performed in this study will improve the understanding of the physiological function of the facial muscles as alternative venous valves.

Abstract According to current literature, 90% of knee ligament injuries involve the medial collateral ligament or the anterior cruciate ligament. In contrast to the medial collateral ligament, which regenerates relatively well, the anterior cruciate ligament demonstrates compromised healing. In the past, there were numerous studies in animal models that examined the healing process of these ligaments, and different explanations were established. Although the healing of these ligaments has been largely investigated and different theories exist, unanswered questions persist. Therefore, the aim of this article is 1) to review the different historical aspects of healing of the medial collateral ligament and present the theories for healing failure of the anterior cruciate ligament; 2) to examine the novel epiligament theory explaining the medial collateral ligament healing process and failure of anterior cruciate ligament healing; and 3) to discuss why the enveloping tissue microstructure of the aforementioned ligaments needs to be examined in future studies. We believe that knowledge of the novel epiligament theory will lead to a better understanding of the normal healing process for implementing optimal treatments, as well as a more holistic explanation for anterior cruciate ligament healing failure.

The rapidity distributions of hydrogen isotopes emitted from central collisions of neutron-rich 132Sn+124Sn and neutron-deficient 108Sn+112Sn systems at 270 MeV/nucleon were investigated at RIKEN-RIBF. The data are compared with antisymmetrized molecular dynamics (AMD) calculations and the rapidity distributions can be reproduced after adjusting the in-medium nucleon-nucleon cross sections. The double ratios between the two reaction systems taken for the relative yields of deuteron to proton (d/p) and triton to proton (t/p) are further examined in the midrapidity domain, where the adjustments in the AMD calculations do not affect much on them. The d/p and t/p double ratios at midrapidity agree well with the ratio of the system neutron numbers and its squared value, respectively, and the rapidity dependence of these double ratios is consistent with a picture of partial mixing of colliding nuclei. By comparing with the AMD model which shows a strong symmetry energy dependence of the t/p double ratio, the experimental result in the midrapidity domain favors the calculation with a symmetry-energy slope parameter around L=46 MeV rather than L=108 MeV.

Background: Translational research refers to scientific findings that have been extensively studied in models and find their way to clinical studies. In a certain sense in translational anatomy a similar application of conventional anatomical knowledge finds its way to clinics in the surgical theatre. With the propagation of endoscopic middle ear surgery there has been a renewed interest in many early anatomical terms, even many years after their discovery, which may threaten the correct and classic eponyms. Moreover, the application of robotic ear surgery executing minimal invasive keyhole accesses requires translation of anatomical knowledge to the sub-millimetric level. Purpose: This review reports relevant anatomy of the temporal bone for robotic cochlear implantation reflecting also on recent revisions of terminology. Results: In 2019, the Terminologia Neuroanatomica (TNA 2017) was accepted at the 19th World Congress of the International Federation of Associations of Anatomists (IFAA) in London as its official terminology for the central and peripheral nervous system and the sense organs. This review follows the terminology of in the TNA, but also compares anatomical and clinical terms to bridge the gap between both approaches, and provides brief descriptions and illustrations of relevant structures for robotic cochlear implantation and elaborates on their significance. With the emergence and more widespread use of the endoscopic ear surgery and image guided ear surgery, visualization of certain anatomical structures has improved. Coinciding, there has been a renewed interest in many early anatomical terms, even many years after their discovery, which may threaten the correct and classic eponyms. Conclusions: Consequently, this review also presents an overview of eponyms associated with specific structures over the years. In Supplementary Tables, the changes in terminology are reported.

The median cubital vein is the most prominent superficial vein in the cubital region and usually the most clearly outlined vein in the entire human body. It can be found quite easily, even in obese, swollen, or shocked patients. It runs diagonally upwards, leaving the cephalic vein and traveling medially to the basilic vein. Topographical relationships make the vein particularly convenient for access in various procedures such as venous punctures. However, high-risk procedures are usually performed in other areas because unusual anatomical variations are possible. A detailed anatomical description of an unusual variant of median cubital vein duplication is presented in this report, including its communications with deep veins and topographical relationships to the bicipital aponeurosis, brachial artery, medial cutaneous nerve of the forearm, and the median nerve. The potential clinical significance of this variant is discussed.

Background: The marginal artery of Drummond (MA) is an anatomically variable blood vessel that forms a major anastomotic network between the superior and inferior mesenteric arteries. It vascularizes the transverse and descending colons and is a major contributor to the collateral circulation of left-colic structures. Purpose: To conduct a systematic review of the MA and highlight the current understanding of its anatomy and role in physiological and pathological vascularization. Methods: The major online databases (Pubmed, Google Scholar, Embase, and Web of Science) were systematically assessed to reveal all available literature pertaining to the MA. Articles judged relevant by the authors were used for the final review. Results: The MA is a key player in the collateral circulation of left-colic structures in the setting of pathological processes affecting their normal vascularization. It helps to maintain perfusion in the event of obstructions and atherosclerosis, and in the cases of obliteration or congenital absence of the mesenteric vessels, it sustains adequate vascularization of the left-colon. The MA has come into increasing prominence as surgeons have become more aware of both iatrogenic injuries to it and its value in mitigating the effects of reduced patency of the mesenteric vessels. Conclusions: The MA continues to become more important to surgeons as both an obstacle and an opportunity in abdominal procedures. Further exploration of its anatomical variability, for example through embryological and dissection studies, will further improve treatment outcomes during abdominal surgery.

Having established and classified the laws of nature, scientists gradually achieved the skill of judging what is most typical and what is rare or deviates from the commonly-observed pattern. Normality in anatomy can be considered relative (linked to a specific set of assumptions) and is inferred from numerous repeated observations. In anatomy textbooks, the term “norm” is associated with such concepts as general pattern, rule, or canon. Deviations from the most common (assumed to be typical) morphology are described as variants or types of organs or anatomical structures. The term “anomaly” is also used in the anatomical and medical literature to describe variations; however, this designation can also be applied to pathological conditions. Nevertheless, the “norm” in anatomy is not as precise a concept as one would wish, and can be considered an approximation. In fact, anatomical variability is the rule, though most variations are within the normal range. Thus, the idea of a medical and anatomical norm is analogous the sorites paradox because the boundaries between what is considered normal and what is anomalous are blurred. Nevertheless, the anatomical norm should only be regarded as an idealized scientific model; anatomical variations should be kept in mind in clinical practice.The aim of this review is to reflect on the question of gross anatomical normality and variability. Particular attention has been paid to what is considered normal in gross anatomy and the premises for recognizing a given structure as normal. The earliest historical sources referring to anatomical variations are described in the paper. The general significance of anatomical variations is also discussed.

Historical sources can serve as an important point of reference for anatomical research. In this report, we present an atypical origin of the brachioradial artery from the distal fourth of the arm. The radial recurrent artery originated from the ulno-interosseous trunk and crossed the brachioradial artery posteriorly at the level of the neck of the radius. This case reported herein was observed during a review of the historical specimens collection prepared in the 19th century by the prominent Polish anatomist Ludwik Karol Teichmann and his collaborators and exhibited in the Anatomy Museum of Jagiellonian University Medical College. The goal of this study was to provide data on the course and branching pattern of a rare variant of the brachioradial artery.

Abstract Background Radial meniscus tears can cause the meniscus to be completely incompetent. This serious type of meniscus tear can be difficult to repair. Techniques have been developed that juxtapose the meniscus tear edges and are able to withstand high loads. The purpose of this study was to determine the load to failure of a reinforced suture bar repair (Rebar Repair) for radial meniscus tear and compare it to the parallel suture technique and cross-stitch technique and to compare mode of failure among all three groups. The hypothesis was that the Rebar Repair will have a higher load to failure than both the parallel technique and the cross-stitch technique and that the Rebar Repair would have a lower rate of suture cutting through the meniscus. Methods Forty-eight menisci were tested from 24 human knee specimens, with 16 menisci in each group evenly distributed between medial and lateral menisci. Radial mid body meniscal tears were recreated and repaired with one of three inside-out techniques: the 2-parallel suture technique, 2 cross-stitch sutures, and the Rebar Repair. The specimens were cycled between 5 N to 30 N and axially loaded to failure perpendicularly across the repair site. Results The average load to failure of the parallel group, cross-stitch group and Rebar Repair was 85.5 N ± 22.0, 76.2 N ± 28.8 and 124.1 N ± 27.1 respectively. The Rebar Repair had a higher load to failure than the parallel group (p

The pancreas is a glandular organ that is responsible for the proper functioning of the digestive and endocrine systems, and therefore, it affects the condition of the entire body. Consequently, it is important to effectively diagnose and treat diseases of this organ. According to clinicians, pancreatitis—a common disease affecting the pancreas—is one of the most complicated and demanding diseases of the abdomen. The classification of pancreatitis is based on clinical, morphologic, and histologic criteria. Medical doctors distinguish, inter alia, acute pancreatitis (AP), the most common causes of which are gallstone migration and alcohol abuse. Effective diagnostic methods and the correct assessment of the severity of acute pancreatitis determine the selection of an appropriate treatment strategy and the prediction of the clinical course of the disease, thus preventing life-threatening complications and organ dysfunction or failure. This review collects and organizes recommendations and guidelines for the management of patients suffering from acute pancreatitis.

Isolated fractures of the atlas are rare in the pediatric population and it is imperative to properly diagnose the injury with accurate radiological evaluation. Herein, we report a case of a six-year-old child who presented with posterior head and neck pain after a fall. His initial workup, which included plain radiographs, missed a fracture of his atlas, which was only later diagnosed with additional imaging. Aside from neck pain, the patient remained neurologically intact and was successfully treated with a hard cervical collar. Isolated pediatric anterior arch fractures of the atlas can be treated conservatively with a hard collar. The case presented here highlights a delayed diagnosis of a fracture of the anterior arch of the atlas. Despite their rarity, various clinicians should maintain a high level of suspicion as these fractures may be easily overlooked in children on plain radiographs. Keywords: Atlas, Fracture, Pediatric

Abstract Background Type 1 Chiari malformation (CM-I) has been historically defined by cerebellar tonsillar position (TP) greater than 3–5 mm below the foramen magnum (FM). Often, the radiographic findings are highly variable, which may influence the clinical course and patient outcome. In this study, we evaluate the inter-operator reliability (reproducibility) of MRI-based measurement of TP in CM-I patients and healthy controls. Methods Thirty-three T2-weighted MRI sets were obtained for 23 CM-I patients (11 symptomatic and 12 asymptomatic) and 10 healthy controls. TP inferior to the FM was measured in the mid-sagittal plane by seven expert operators with reference to McRae’s line. Overall agreement between the operators was quantified by intraclass correlation coefficient (ICC). Results The mean and standard deviation of cerebellar TP measurements for asymptomatic (CM-Ia) and symptomatic (CM-Is) patients in mid-sagittal plane was 6.38 ± 2.19 and 9.57 ± 2.63 mm, respectively. TP measurements for healthy controls was 0.48 ± 2.88 mm. The average range of TP measurements for all data sets analyzed was 7.7 mm. Overall operator agreement for TP measurements was relatively high with an ICC of 0.83. Conclusion The results demonstrated a large average range (7.7 mm) of measurements among the seven expert operators and support that, if economically feasible, two radiologists should make independent measurements before radiologic diagnosis of CM-I and surgery is contemplated. In the future, an objective diagnostic parameter for CM-I that utilizes automated algorithms and results in smaller inter-operator variation may improve patient selection.

In the past two decades, pions created in the high density regions of heavy ion collisions have been predicted to be sensitive at high densities to the symmetry energy term in the nuclear equation of state, a property that is key to our understanding of neutron stars. In a new experiment designed to study the symmetry energy, the multiplicities of negatively and positively charged pions have been measured with high accuracy for central 132Sn+124Sn, 112Sn+124Sn, and 108Sn+112Sn collisions at E/A=270 MeV with the SπRIT Time Projection Chamber. While individual pion multiplicities are measured to 4% accuracy, those of the charged pion multiplicity ratios are measured to 2% accuracy. We compare these data to predictions from seven major transport models. The calculations reproduce qualitatively the dependence of the multiplicities and their ratios on the total neutron and proton number in the colliding systems. However, the predictions of the transport models from different codes differ too much to allow extraction of reliable constraints on the symmetry energy from the data. This finding may explain previous contradictory conclusions on symmetry energy constraints obtained from pion data in Au+Au system. These new results call for still better understanding of the differences among transport codes, and new observables that are more sensitive to the density dependence of the symmetry energy.

Background: The importance of cardiac examination is supported by the ever-increasing incidence of heart disease. Traditional examination and auscultation techniques may not provide the level of sensitivity required for identifying certain conditions. Development of cardiac ultrasound (echocardiography) techniques has added greatly to the discipline. Ultrasound images do not only provide a means of diagnosis but allow for the development of treatment modalities and easy monitoring of disease progression. Results: Cardiac images may be obtained via several techniques; some are invasive while most are not. Transthoracic ultrasound may be achieved via several windows in different planes of view and is non-invasive. While it allows for better imaging of all cardiac structures, some parts such as the mitral and aortic valve function can be viewed best by transesophageal echocardiography, a more invasive technique. Each modality and window tend to be more sensitive to certain cardiac structures than others. Conclusions: This review discusses the different modalities and their advantages and provides a comparison to other imaging modalities.

Introduction: In the upper there are different neural entrapment sites that can be associated with neighboring structures which in turn can mimic other neural entrapments syndromes. The objective of this study was to review the literature concerning neuromusculoskeletal anatomical variations in the upper limb and their possible clinical correlations with certain pathologies or syndromes. Methods: A systematic literature search over different databases was used to examine the relationship between anatomical variations of neuromusculoskeletal structures and pathologies in the upper limb, using the search strategy proposed by the Cochrane Handbook for Systematic Reviews of Interventions. Results: Analysis of the full text studies after the exclusion criteria had been applied showed that anatomical variations in the upper limb correlated in one third of the studies to nerve entrapment, such compressions frequently being attributable to some type of accessory muscle or variation in its insertion site. This demonstrates the importance of knowing the normal anatomy in order to investigate these structures and their possible variations, thus avoiding a non-specific differential diagnosis. Conclusions: This literature review does not address a single type of anatomical variation but gives guidelines for considering different structures of the upper limb with anatomical variations that could predispose to some type of upper limb neural entrapment.

The COVID-19 pandemic swept across the world, altering the structure and existence of graduate medical education programs across all disciplines. Orthopaedic residency programs can adapt during these unprecedented times to continue providing meaningful education to trainees and to continue providing high-quality patient care, all while keeping both residents and patients safe from disease. The purpose of this review was to evaluate the literature and describe evidence-based changes that can be made in an orthopaedic residency program to ensure patient and resident safety while sustaining the principles of graduate medical education during the COVID-19 pandemic. We describe measures that can be enacted now or during future pandemics, including workforce and occupational modifications, personal protective equipment, telemedicine, online didactic education, resident wellness, return to elective surgery, and factors affecting medical students and fellows. After a review of these strategies, programs can make changes for sustainable improvements and adapt to be ready for second-wave events or future pandemics. Level of Evidence: Level V.

The carotid sinus nerve (CSN) originates from the glossopharyngeal nerve, and consists of afferent fibers responsible for mediating the baroreceptor reflex. This case study provides the first report of a neuronal loop linking the glossopharyngeal nerve to the vagus nerve, and supplying dual innervation to the CSN. Although few anatomical studies exist on the nerve, anatomical variations of the CSN have been documented, and may be clinically relevant in procedures with close proximity to this nerve. Keywords: Carotid sinus nerve, Anatomy, Glossopharyngeal nerve, Vagus nerve, Hering's nerve

Background Nerve root tethering upon dorsal spinal cord (SC) migration has been proposed as a potential mechanism for postoperative C5 palsy (C5P). To our knowledge, this is the first study to investigate this relationship by anatomically comparing C5–C6 nerve root translation before and after root untethering by cutting the cervical foraminal ligaments (FL). Objective The aim of this study is to determine if C5 root untethering through FL cutting results in increased root translation. Methods Six cadaveric dissections were performed. Nerve roots were exposed via C4–C6 corpectomies and supraclavicular brachial plexus exposure. Pins were inserted into the C5–C6 roots and adjacent foraminal tubercle. Translation was measured as the distance between pins after the SC was dorsally displaced 5 mm before and after FL cutting. Clinical feasibility of FL release was examined by comparing root translation between standard and extended (complete foraminal decompression) foraminotomies. Translation of root levels before and after FL cutting was compared by two-way repeated measures analysis of variance. Statistical significance was set at 0.05. Results Significantly more nerve root translation was observed if the FL was cut versus not-cut, p = 0.001; no difference was seen between levels, p = 0.33. Performing an extended cervical foraminotomy was technically feasible allowing complete FL release and root untethering, whereas a standard foraminotomy did not. Conclusion FL tether upper cervical nerve roots in their foramina; cutting these ligaments untethers the root and increases translation suggesting they could be harmful in the context of C5P. Further investigation is required examining the value of root untethering in the context of C5P.

Abstract Background The spinal subarachnoid space (SSS) has a complex 3D fluid-filled geometry with multiple levels of anatomic complexity, the most salient features being the spinal cord and dorsal and ventral nerve rootlets. An accurate anthropomorphic representation of these features is needed for development of in vitro and numerical models of cerebrospinal fluid (CSF) dynamics that can be used to inform and optimize CSF-based therapeutics. Methods A subject-specific 3D model of the SSS was constructed based on high-resolution anatomic MRI. An expert operator completed manual segmentation of the CSF space with detailed consideration of the anatomy. 31 pairs of semi-idealized dorsal and ventral nerve rootlets (NR) were added to the model based on anatomic reference to the magnetic resonance (MR) imaging and cadaveric measurements in the literature. Key design criteria for each NR pair included the radicular line, descending angle, number of NR, attachment location along the spinal cord and exit through the dura mater. Model simplification and smoothing was performed to produce a final model with minimum vertices while maintaining minimum error between the original segmentation and final design. Final model geometry and hydrodynamics were characterized in terms of axial distribution of Reynolds number, Womersley number, hydraulic diameter, cross-sectional area and perimeter. Results The final model had a total of 139,901 vertices with a total CSF volume within the SSS of 97.3 cm3. Volume of the dura mater, spinal cord and NR was 123.1, 19.9 and 5.8 cm3. Surface area of these features was 318.52, 112.2 and 232.1 cm2 respectively. Maximum Reynolds number was 174.9 and average Womersley number was 9.6, likely indicating presence of a laminar inertia-dominated oscillatory CSF flow field. Conclusions This study details an anatomically realistic anthropomorphic 3D model of the SSS based on high-resolution MR imaging of a healthy human adult female. The model is provided for re-use under the Creative Commons Attribution-ShareAlike 4.0 International license (CC BY-SA 4.0) and can be used as a tool for development of in vitro and numerical models of CSF dynamics for design and optimization of intrathecal therapeutics.