Search

BACKGROUND: Dark-field radiography imaging exploits the wave character of x-rays to measure small-angle scattering on material interfaces, providing structural information with low radiation exposure. We explored the potential of dark-field imaging of bone microstructure to improve the assessment of bone strength in osteoporosis. METHODS: We prospectively examined 14 osteoporotic/osteopenic and 21 non-osteoporotic/osteopenic human cadaveric vertebrae (L2-L4) with a clinical dark-field radiography system, micro-computed tomography (CT), and spectral CT. Dark-field images were obtained in both vertical and horizontal sample positions. Bone microstructural parameters (trabecular number, Tb.N; trabecular thickness, Tb.Th; bone volume fraction, BV/TV; degree of anisotropy, DA) were measured using standard ex vivo micro-CT, while hydroxyapatite density was measured using spectral CT. Correlations were assessed using Spearman rank correlation coefficients. RESULTS: The measured dark-field signal was lower in osteoporotic/osteopenic vertebrae (vertical position, 0.23 ± 0.05 versus 0.29 ± 0.04, p

INTRODUCTION: Adjunctive suture augmentation of patellar plate fixation has yet to be investigated. Our biomechanical study sought to evaluate whether suture augmentation improves dorsal patellar locking plate fixation. Our hypothesis was that suture augmentation would improve fixation of this construct. METHODS: A transverse patella fracture in six matched cadaveric pairs was stabilized using a patellar locking plate with or without suture augmentation. Specimens were tested at 60° knee flexion with load placed through quadriceps. Cyclic loading followed by load to failure was done. Stiffness, deformation at peak, and nonrecoverable deformation were calculated. RESULTS: During cyclic loading, suture augmentation demonstrated a higher average stiffness throughout all loads. At the final cycle, deformation was markedly higher without suture augmentation. Average load to failure was higher with suture augmentation. Maximum load to failure occurred at 2500 N in both groups. CONCLUSION: Suture augmentation in a transverse patellar fracture model improved dorsal plate fixation, leading to less fracture displacement at the final load. Although suture augmentation demonstrated higher stiffness and lower deformation, these trends were not statistically significant. In both groups, plate fixation sustained very high loads, which reflects the fixation strength of the dorsal locking plate and screw construct in this fracture model.

BackgroundThe appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis.MethodsA total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples.ResultsFully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P

BackgroundThe calcaneal enthesis, an osseous footprint where the Achilles tendon seamlessly integrates with the bone, represents a complex interface crucial for effective force transmission. Bone adapts to mechanical stress and remodels based on the applied internal and external forces. This study explores the relationship between the elasticity of the Achilles tendon enthesis and the bone microstructure in the calcaneal crescent.MethodsIn total, 19 calcaneal-enthesis sections, harvested from 10 fresh-frozen human cadaveric foot-ankle specimens (73.8 ± 6.0 years old, seven female), were used in this study. Indentation tests were performed at the enthesis region, and Hayes' elastic modulus was calculated for each specimen. Micro-CT scanning was performed at 50-micron voxel size to assess trabecular bone microstructure within six regions of interest (ROIs) and the cortical bone thickness along the calcaneal crescent.ResultsSignificant Spearman correlations were observed between the enthesis elastic modulus and trabecular bone thickness in the distal entheseal (ROI 3) and proximal plantar (ROI 4) regions (R = 0.786 and 0.518, respectively).ConclusionThis study highlights the potential impacts of Achilles tendon enthesis on calcaneal bone microstructure, which was pronounced in the distal calcaneal enthesis, suggesting regional differences in load transfer mechanism that require further investigation.

Background: Dry needling (DN) has emerged as a popular therapeutic intervention for managing musculoskeletal pain. While major adverse events are generally rare, those that have been reported in vulnerable areas such as the spine and thorax can be serious and warrant further investigation regarding safe techniques in and around these areas. Purpose: The purpose of this study was to reproduce the methods employed by Williams et al. but with an inferior-medial multifidus DN technique to determine if a dry needle can penetrate the ligamentum flavum (LF) and breach the spinal canal at the thoracolumbar junction. Study Design: Descriptive Cadaveric study. Methods: The procedure was performed on a cadaver in the prone position. The needle was advanced under ultrasound guidance to determine if a 0.30 x 40 mm dry needle inserted lateral to the spinous process of T12 and directed inferior-medially could penetrate the LF and enter the spinal canal. Results: A 0.30 x 40 mm dry needle inserted 1.9 cm lateral to the spinous process of T12 was able to traverse the space between the vertebral laminae of T12 and L1, penetrate the LF, and enter the spinal canal with an inferior-medial needle angulation of 33-degrees medial and 18-degrees inferior. Conclusion: The results of this study demonstrate the feasibility of a dry needle entering the spinal canal at the thoracolumbar junction using an inferior-medial technique. These findings support the potential role of ultrasound guidance in the training and clinical practice of DN, especially in regions where safety issues have been documented. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Objectives The lateral supraorbital (LSO) approach is a less-invasive alternative to the pterional craniotomy that provides rapid transsylvian access. Establishing familiarity with the LSO technique and its features as compared with other anterolateral approaches is an important component of advanced skull base training. We present a step-by-step demonstration of the LSO approach using cadaveric dissection in a manner that is digestible for trainees at various levels. Design This is anatomic step-by-step dissection and representative case series. Setting This study was carried out in the cadaveric dissection laboratory. Participants A formalin-fixed, latex-injected cadaveric head specimen was dissected under microscopic magnification by a neurosurgery resident under faculty supervision. Following dissection, representative case applications were reviewed. Main Outcome Measures Dissection and case illustration were the main outcome measures. Results A single-layer myocutaneous flap is developed, and a single-burr-hole technique is used, followed by extensive drilling of the sphenoid wing. The dura is opened in a C-shaped fashion centered on the Sylvian fissure, exposing the inferior frontal and superior temporal lobes. Labeled photographs of dissections with pertinent anatomical structures are presented. Three case examples illustrating the versatility of the LSO approach, including the resection of a large pituitary adenoma, an inferior frontal melanoma metastasis presenting to the Sylvian surface, and a frontoinsular low-grade glioma, are reviewed. Conclusion As compared with the pterional craniotomy, the LSO approach involves a shorter incision, smaller craniotomy, and faster exposure; it can be conveniently tailored to various indications. Understanding the step-by-step dissection and indications of the LSO approach is of paramount importance to neurosurgery trainees. [ABSTRACT FROM AUTHOR]

The transverse sinus (TS) is often involved with pathology for structural reasons. The aim of this study was to improve understanding of the anatomy along the groove of the TS and sigmoid sinus (SS), to discuss the relationship between the bony features and pathologies affecting the TS. Seventy dry skulls (140 sides) were used for detailed observation of the TS and SS grooves using gross investigation coupled with transillumination. Bony features such as the mastoid foramen (MF), occipital foramen (OF), granular foveolae (GF), and absence of the TS groove were evaluated, and a classification based on numbers of findings was proposed. The most common internal groove finding was MF (79.3%), followed by absent TS groove (32.9%), and OF (14.3%). MF was statistically more frequent on the left side (91.4%) than the right (67.1%) (p = 0.036); OF was statistically more frequent on the right side (24.3%) than the left (4.3%) (p = 0.008). Absent TS groove was more prevalent on the left side (54.3%) than the right (11.4%) (p = 0.000). A bony prominence (BP) was identified in 15.7% (11 skulls) and there were significant differences from the controls. The type III class (three internal groove findings) was the most prevalent, followed by type II (two findings). The complex and integral role of the bony features described here, and their particularities in normal patients or in those with DVS pathologies, is not well understood. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction Warfighters are issued hard body armor designed to defeat ballistic projectiles. The resulting backface deformation can injure different thoracoabdominal organs. Developed over decades ago, the behind armor blunt impact criterion of maximum 44 mm depth in clay continues to be used independent of armor type or impact location on the thoracoabdominal region covered by the armor. Because thoracoabdominal components have different energy absorption capabilities, their mode of failures and mechanical properties are different. These considerations underscore the lack of effectiveness of using the single standard to cover all thoracoabdominal components to represent the same level of injury risk. The objective of this pilot study is to conduct cardiac impact tests with a live animal model and analyze biomechanical injury candidate metrics for behind armor blunt trauma applications. Materials and Methods Live swine tests were conducted after obtaining approvals from the U.S. DoD. Trachea tubes. An intravenous line were introduced into the swine before administering anesthesia. Pressure transducers were inserted into lungs and aorta. An indenter simulating backface deformation profiles produced by body armor from military-relevant ballistics to human cadavers delivered impact to the heart region. The approved test protocol included 6-hour monitoring and necropsies. Indenter accelerometer signals were processed to compute the velocity and deflection, and their peak magnitudes were obtained. The deflection-time signal was normalized with respect to chest depth along the impact axis. The peak magnitude of the viscous criterion, kinetic energy, force, momentum and stiffness were obtained. Results Out of the 8 specimens, 2 were sham controls. The mean total body mass and soft tissue thickness at the impact site were 81.1 ± 4.1 kg and 3.8 ± 1.1 cm. The peak velocities ranged from 30 to 59 m/s, normalized deflections ranged from 15 to 21%, and energies ranged from 105 to 407 J. The range in momentum and stiffness were 7.0 to 13.9 kg-m/s and 22.3 to 79.9 N/m. The maximum forces and impulse data ranged from 2.9 to 11.7 kN and 1.9 to 5.8 N-s. The peak viscous criterion ranged from 2.0 to 5.3 m/s. One animal did not sustain any injuries, 2 had cardiac injuries, and others had lung and skeletal injuries. Conclusions The present study applied blunt impact loads to the live swine cardiac region and determined potential candidate injury metrics for characterization. The sample size of 6 swine produced injuries ranging from none to pure skeletal to pure organ trauma. The viscous criterion metric associated with the response of the animal demonstrated a differing pattern than other variables with increasing velocity. These findings demonstrate that our live animal experimental design can be effectively used with testing additional samples to develop behind armor blunt injury criteria for cardiac trauma in the form of risk curves. Injury criteria obtained for cardiac trauma can be used to enhance the effectiveness of the body armor, reduce morbidity and mortality, and improve warfighter readiness in combat operations. [ABSTRACT FROM AUTHOR]

Introduction Ventral hernia repair cost the U.S. healthcare system nearly 3 billion dollars annually. Surgical repair is a critical competency for residents yet hernia recurrence rates following mesh-based repair range from 0.8% to 24%. Improving surgical techniques using cadavers is often cost-prohibited for many education programs and limited research exists using simulation models with a corresponding hernia repair curriculum in the graduate medical education setting. This pilot project aimed to develop a low cost, easily reproducible novel abdominal wall reconstruction model and pilot-test the ventral hernia repair curriculum to inform further refinement prior to formal evaluation. Material and Methods This descriptive study pilot-tested the newly refined Abdominal Wall Surgical Skills Operative Model (AWSSOM) simulator for ventral hernia repair with mesh and its corresponding 2-h training curriculum for use at all levels of general surgery graduate medical education. The AWSSOM is a 3D printed synthetic anatomically realistic abdominal wall model consisting of silicone cured layers of skin, fat, rectus abdominis and a posterior rectus sheath fascia, and silicone tubules to simulate lateral neurovascular bundles. The curriculum incorporated didactic content reflecting surgical practice guidelines, hands-on practice, and faculty guidance promoting interactive critical thinking development during task performance. A pre-/post-assessment included a 10-item knowledge test, a 19-item psychomotor assessment, and 4-items confidence survey to examine changes in performance, knowledge, and confidence in competently completing the ventral hernia repair technique. Descriptive statistics were used to report the limited results of six military surgical resident participants and inform further model and curriculum refinement prior to formal evaluation. Results The five-layer AWSSOM model was manufactured in 65 h at a material cost of $87 per model frame, is reusable model, and secure base. Six surgical residents were recruited; only four completed both pre- and post-tests due to resident schedule conflicts. The average increase in knowledge was 25%, although variable changes in confidence were observed over the four program year participants. A larger sample size and a control group are needed to demonstrate curriculum effectiveness at improving knowledge, performance, and confidence in ventral hernia repair with mesh and better delineate if high scores translate to better operative skills. A key improvement requested by residents was a more secure model base for dissection and performance of the hernia repair. Conclusions The novel abdominal wall surgical skills operative model fills an important proof of concept gap in simulation training. It is low cost with the potential to improve cognitive and psychomotor skills, as well as confidence to competently complete ventral hernia repair with mesh in the graduate medical education setting. Prior to formal effectiveness testing, our lessons learned should be addressed in both the model and curriculum. Future studies must include an adequately powered statistical evaluation with a larger sample across all levels of training. [ABSTRACT FROM AUTHOR]

Background: Surgical approaches to the cavernous sinus (CS) and middle cranial fossa (MCF) can be challenging, particularly for young neurosurgeons. The anteromedial (Mullan's) triangle is a triangle by the side of the CS and constitutes part of the floor of the MCF. The contents include the sphenoid sinus, superior ophthalmic vein, and sixth cranial nerve. The literature contains very little research that has precisely defined and measured the anteromedial triangle while considering anatomical variances minimally. Methodology: The present study was conducted on the skulls of 25 adult human cadavers which were dissected to expose the anteromedial (Mullan's) triangle on both sides. After precisely defining the triangle on each side, measurements of the three borders were taken, and using Heron's formula, the area of each triangle was calculated. Results: On average, the length of the medial border was 12.5 (+ 3.1 mm); the length of the lateral border was 9.9 (+ 3.1 mm); the length of the base was 10.75 (+ 2.4 mm) and the area of the anteromedial triangle was 43.9 (+ 15.06 mm2). Conclusion: Precise anatomical knowledge of the Mullan's triangle enables the treatment of disorders in often deformed anatomy or difficult-to-access structures. That is the reason it is important to gain a thorough understanding of the surgical anatomy and to adopt a safe procedure. [ABSTRACT FROM AUTHOR]

Background: Distal radioulnar joint (DRUJ) instability is a common post-traumatic complication, often leading to chronic pain and dysfunction. Current reconstructive techniques, such as the single suture button construct, offer suboptimal stabilization in certain motions. This study aimed to evaluate whether a double suture button construct provides greater stability than the single construct in a cadaver model of DRUJ instability. We hypothesized that the double suture button construct would more effectively minimize dorsal translation of the radius relative to the ulna. Methods: We used nine freshly frozen human cadaver upper extremities, destabilized the DRUJ, and then reconstructed the joint using three different suture button constructs: single transverse, double (transverse + oblique), and single oblique. The specimens were secured in a custom-designed testing apparatus to measure dorsal translation of the radius. The study proceeded in five stages: stable DRUJ, unstable DRUJ, and reconstruction using a single transverse, double (transverse + oblique), and single oblique suture button construct. Dorsal translation was measured at neutral, 45° pronation, and 45° supination. Statistical comparisons of mean values were conducted for each stage. Results: Reconstruction with the transverse, transverse plus oblique, and oblique suture button constructs resulted in statistically significant reductions in dorsal translation compared to the unstable DRUJ (p < 0.001 for all). The double-suture button construct significantly minimized dorsal translation in all positions, restoring stability comparable to a stable DRUJ: neutral (p = 1.000), pronation (p = 0.963), and supination (p = 1.000). In contrast, single constructs failed to fully restore stability in pronation and supination. Conclusion: The double suture button construct provides significantly greater stabilization of the DRUJ compared to the single construct. These findings suggest that the double construct could be a more effective option for treating DRUJ instability, particularly in restoring normal joint function during various motions. Further research is warranted to confirm these results in clinical settings. [ABSTRACT FROM AUTHOR]

Objectives:Methods:Results:Conclusions:Hearing implants often limit the assessment of magnetic resonance examinations due to susceptibility artefacts. Our aim was to evaluate the impact of artefacts attributed to the Osia®2 implant system in terms of utility in visualizing selected cranial structures.A BI300 implant and an OSI200 actuator were implanted into a human cadaver head in the audiologically most favourable position according to the manufacturer’s guidelines. Scanning was accomplished using the institutional head and inner ear protocol with a General Electric 1.5 Tesla scanner with retained and removed implant magnet, extended with T1 and T2 weighted sequences with metal-artefact reduction (MAVRIC SL). Image quality was evaluated by three radiologists.The Osia®2 produced significant artefacts in most of the series of standard imaging sequences predominantly on the ipsilateral side of the head. The majority of the artefacts were caused by the implant magnet. Even without removing the magnet, MAVRIC SL improved image quality to such an extent that it became comparable with that after magnet removal.The standard sequences suffer considerable quality loss due to the artefacts, attributed predominantly to the magnetic component. Metal-artefact reduction sequences are effective in obtaining sufficient-to-good quality images without surgical magnet removal. [ABSTRACT FROM AUTHOR]

Objectives: To assess needle placement accuracy in the rectus abdominis (RA) muscle during dry needling (DN) without entering the peritoneum. Methods: Two physical therapists performed DN on a cadaver, making 10 attempts each to needle the RA without entering the peritoneum. Techniques followed two common DN approaches. Ultrasound verified needle depth and safety. Results: Seventy percent of attempts were recorded as safe needle placement, while 30% were unsafe. Accurate RA needle placement without peritoneal entry occurred in 55% of attempts. Discussion/Conclusion: Inadvertent peritoneal needle placement during RA DN poses risks regardless of experience. Ultrasound guidance may enhance safety and precision in clinical practice. [ABSTRACT FROM AUTHOR]

As few anaesthetists provide lumbar erector spinae block for disc surgery, there is a need to provide training to enable a randomised controlled trial investigating analgesia after painful spinal surgery (NIHR153170). The primary objective of the study was to develop and measure the construct validity of a checklist for assessment of skills in performing lumbar and thoracic erector spinae fascial plane injection using soft-embalmed Thiel cadavers. Twenty-four UK consultant regional anaesthetists completed two iterations of a Delphi questionnaire. The final checklist consisted of 11 steps conducive to best practice. Thereafter, we validated the checklist by comparing the performance of 12 experts with 12 novices, each performing lumbar and thoracic erector spinae plane injections or fascia iliaca, serrato-pectoral (PEC II) and serratus injections, randomly allocated to the left and right sides of six soft-embalmed Thiel cadavers. Six expert, trained raters blinded to operator and site of block examined 120 videos each. The mean (95% confidence interval) internal consistency of the 11-item checklist for erector spinae plane injection was 0.72 (0.63–0.79) and interclass correlation was 0.88 (0.82–0.93). The checklist showed construct validity for lumbar and thoracic erector spinae injection, experts vs novices {median (interquartile range [range]) 8.0 (7.0–10.0 [1–11]) vs 7.0 (5.0–9.0 [4–11]), difference 1.5 (1.0–2.5), P <0.001}. Global rating scales showed construct validity for lumbar and thoracic erector spinae injection, 28.0 (24.0–31.0 [7–35]) vs 21.0 (17.0–24.0 [7–35]), difference 7.5 (6.0–8.5), P <0.001. The most difficult items to perform were identifying the needle tip before advancing and always visualising the needle tip. Instrument handling and flow of procedure were the areas of greatest difficulty on the global rating scale (GRS). Checklists and GRS scores correlated. There was homogeneity of regression slopes controlling for status, type of injection, and rater. Generalisability analysis showed a high reliability using the checklist and GRS for all fascial plane blocks (Rho [ρ2] 0.93–0.96: Phi [ϕ] 0.84–0.87). An 11-point checklist developed through a modified Delphi process to provide best practice guidance for fascial plane injection showed construct validity in performing lumbar and thoracic erector spinae fascial plane injection in soft-embalmed Thiel cadavers. [ABSTRACT FROM AUTHOR]

Background: The xiphoid process (XP) in animals such as sheep and rats are well known to have cartilage called xiphoidal cartilage (XC). In humans, the cartilage in the xiphoid process is considered an anatomical variant and is not well understood. The aim of this study was to investigate the morphology of the XP. Methods: A total of twenty embalmed European descendant cadaveric sterna (aged 52 to 98 years) were used. Transilluminated XPs and midsagittal sections of XPs were used to examine the bone and cartilage. Subsequently, a sagittally-sectioned XP was harvested for histology and stained with Masson's trichrome. The results of the transillumination and histological examinations were compared qualitatively. Results: The dark area visible in transilluminated XPs was consistent with the bony part in the midsagittal XP sections, which contained bone marrow; the bright area was consistent with the cartilage part in the midsagittal XP sections. This was all demonstrated histologically. Most of the XPs (85%) had some portion of cartilage. The XP was classified into four types based on its proportions of bone and cartilage: Type I, no ossification (< 1/3 ossification) 45%; Type II, minor ossification (1/3 − 1/2 ossification) 20%; Type III, major ossification (1/2–2/3 ossification) 20%; Type IV, complete ossification (> 2/3 ossification) 15%. Most of the XPs (85%) had bone and cartilage, which could have been overlooked in studies using skeletons or CT. Conclusion: Previous studies probably underestimated or overestimated the size of the XP. The XC needs to be considered as normal anatomy. [ABSTRACT FROM AUTHOR]

Background: It is very well known that the supraclavicular nerve (SCN) which occupies the inferior part of the superficial cervical plexus basically originates from the ventral rami of C2–C4, then travels caudally into the investing layer of the deep cervical fascia (IL-DCF) alternatively termed the "prevertebral fascia." Methods: This cadaveric study (a total of 6 soft-embalmed cadavers and bilateral dissections, i.e. 12 specimens) intended to ascertain the location of SCN within the layers of the IL-DCF. We hypothesized that ultrasonography identification of SCN within the IL-DCF and needle tip positioned between the layers of IL-DCF provide an alternative site for the blockade of the SCN. Results: After dissection, we described a compact double-layered IL-DCF hosting the SCNs and a specific topographic arrangement at the C4 root with SCN lateral and C4 branches of the phrenic nerve medial to the C4. Conclusion: We recommend another alternative site for the SCN block at a site in the compact double layer of IL-DCF. We conclude that a caudal site at the exit of SCN from the IL-DCF would be appropriate to perform the intervention. [ABSTRACT FROM AUTHOR]

Instrumented mouthguard systems (iMGs) are commonly used to study rigid body head kinematics across a variety of athletic environments. Previous work has found good fidelity for iMGs rigidly fixed to anthropomorphic test device (ATD) headforms when compared to reference systems, but few validation studies have focused on iMG performance in human cadaver heads. Here, we examine the performance of two boil-and-bite style iMGs in helmeted cadaver heads. Three unembalmed human cadaver heads were fitted with two instrumented boil-and-bite mouthguards [Prevent Biometrics and Diversified Technical Systems (DTS)] per manufacturer instructions. Reference sensors were rigidly fixed to each specimen. Specimens were fitted with a Riddell SpeedFlex American football helmet and impacted with a rigid impactor at three velocities and locations. All impact kinematics were compared at the head center of gravity. The Prevent iMG performed comparably to the reference system up to ~ 60 g in linear acceleration, but overall had poor correlation (CCC = 0.39). Prevent iMG angular velocity and BrIC generally well correlated with the reference, while underestimating HIC and overestimating HIC duration. The DTS iMG consistently overestimated the reference across all measures, with linear acceleration error ranging from 10 to 66%, and angular acceleration errors greater than 300%. Neither iMG demonstrated consistent agreement with the reference system. While iMG validation efforts have utilized ATD testing, this study highlights the need for cadaver testing and validation of devices intended for use in-vivo, particularly when considering realistic (non-idealized) sensor-skull coupling, when accounting for interactions with the mandible and when subject-specific anatomy may affect device performance. [ABSTRACT FROM AUTHOR]

Background: It is very well known that the supraclavicular nerve (SCN) which occupies the inferior part of the superficial cervical plexus basically originates from the ventral rami of C2–C4, then travels caudally into the investing layer of the deep cervical fascia (IL-DCF) alternatively termed the “prevertebral fascia.” Methods: This cadaveric study (a total of 6 soft-embalmed cadavers and bilateral dissections, i.e. 12 specimens) intended to ascertain the location of SCN within the layers of the IL-DCF. We hypothesized that ultrasonography identification of SCN within the IL-DCF and needle tip positioned between the layers of IL-DCF provide an alternative site for the blockade of the SCN. Results: After dissection, we described a compact double-layered IL-DCF hosting the SCNs and a specific topographic arrangement at the C4 root with SCN lateral and C4 branches of the phrenic nerve medial to the C4. Conclusion: We recommend another alternative site for the SCN block at a site in the compact double layer of IL-DCF. We conclude that a caudal site at the exit of SCN from the IL-DCF would be appropriate to perform the intervention.

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.

Abstract Background Dark-field radiography imaging exploits the wave character of x-rays to measure small-angle scattering on material interfaces, providing structural information with low radiation exposure. We explored the potential of dark-field imaging of bone microstructure to improve the assessment of bone strength in osteoporosis. Methods We prospectively examined 14 osteoporotic/osteopenic and 21 non-osteoporotic/osteopenic human cadaveric vertebrae (L2–L4) with a clinical dark-field radiography system, micro-computed tomography (CT), and spectral CT. Dark-field images were obtained in both vertical and horizontal sample positions. Bone microstructural parameters (trabecular number, Tb.N; trabecular thickness, Tb.Th; bone volume fraction, BV/TV; degree of anisotropy, DA) were measured using standard ex vivo micro-CT, while hydroxyapatite density was measured using spectral CT. Correlations were assessed using Spearman rank correlation coefficients. Results The measured dark-field signal was lower in osteoporotic/osteopenic vertebrae (vertical position, 0.23 ± 0.05 versus 0.29 ± 0.04, p

Abstract Background Understanding human anatomy is fundamental to building medical competencies. This study explored the diverse perceptions of medical students in Saudi Arabia and Egypt concerning virtual dissection applications. Methods Students from different Saudi and Egyptian governmental universities were invited. The online questionnaire covered the sociodemographic characteristics, students’ perception of the advantages of virtual anatomy applications, satisfaction with their efficiency, and their recommendation to use them. Comparisons were performed in country-wise and then university-wise patterns. Significance was considered with a P

Background: The aim of this systematic review was to investigate the available literature on the biomechanical characteristics of the acromioclavicular (AC) joint to identify trends in translational parameters and contributions of the various ligamentous structures supporting the joint. Methods: A comprehensive literature search was conducted in the Web of Science, Scopus, and PubMed databases until October 2023 to identify articles reporting on the biomechanical characteristics of the AC joint. Non cadaveric or projects involving reconstruction were excluded. Consistent parameters evaluated were anterior, posterior, superior, and inferior translation. The data were extracted from the included articles and summarized. Results: 11 biomechanical papers were reviewed from six different countries — United States (n = 6), France (n = 1), Austria (n = 1), Thailand (n = 1), United Kingdom (n = 1), and Japan (n = 1). The total number of specimens included across the reviewed papers was 141. All 11 papers reported the data on an intact model (coracoclavicular and AC ligaments intact). Seven papers assessed the translational results of the AC sectioned condition, finding a greater increase in anterior-posterior (AP) laxity relative to SI. 3 papers evaluated coracoclavicular ligament sectioning, finding increased superior-inferior laxity relative to AP. Only one study involved ligament sectioning isolating the anterior-inferior bundle of the AC joint. Conclusion: This review highlights the key AP and superior-inferior constraints of both the intact and ligament sectioned AC joint. The inconsistency of AC joint testing parameters and the lack of thorough translation studies indicate a necessity for increased attention in the overall assessment of shoulder stability to close the gap in the foundational biomechanical research.

Abstract Background Distal radioulnar joint (DRUJ) instability is a common post-traumatic complication, often leading to chronic pain and dysfunction. Current reconstructive techniques, such as the single suture button construct, offer suboptimal stabilization in certain motions. This study aimed to evaluate whether a double suture button construct provides greater stability than the single construct in a cadaver model of DRUJ instability. We hypothesized that the double suture button construct would more effectively minimize dorsal translation of the radius relative to the ulna. Methods We used nine freshly frozen human cadaver upper extremities, destabilized the DRUJ, and then reconstructed the joint using three different suture button constructs: single transverse, double (transverse + oblique), and single oblique. The specimens were secured in a custom-designed testing apparatus to measure dorsal translation of the radius. The study proceeded in five stages: stable DRUJ, unstable DRUJ, and reconstruction using a single transverse, double (transverse + oblique), and single oblique suture button construct. Dorsal translation was measured at neutral, 45° pronation, and 45° supination. Statistical comparisons of mean values were conducted for each stage. Results Reconstruction with the transverse, transverse plus oblique, and oblique suture button constructs resulted in statistically significant reductions in dorsal translation compared to the unstable DRUJ (p

Purpose: This study aimed to define a new surgical method using a neurotized platysma free flap to provide dynamic reanimation, enhanced functional recovery, and low morbidity for blepharoptosis repair. Methods: Ten hemifaces and neck halves of five formalin-fixed cadavers were included in the study. The origin of the neurovascular structures of the pedicle was identified at the submandibular triangle. A 5 × 3 cm platysma flap was dissected. For the recipient side, the main donor vascular structures were observed at the frontal part of the temporal region. The diameters of the donor structures were measured with a digital Vernier caliper. The statistical analysis of the study was performed with Jamovi statistical software version 2.3.36. P < 0.05 was accepted as a statistically significant value. Results: At the donor region, the pedicle included branches of the cervical branch of the facial nerve and the facial artery in all specimens. However, the venous graft pedicle origin could be either the facial vein or the lingual vein. At the recipient region, the mean diameters of the most anterior nerves, arteries, and veins were 1, 2.03, and 2.37 mm respectively. In a side comparison of pedicle variables, only pedicle artery diameter and lateral palpebral commissure-anterior superior point of auricula distance had statistically significant differences between hemifaces. Conclusion: A 5 × 3 cm size platysma flap located in the submandibular trigone would be a good choice for functional blepharoptosis surgery. The thin structure and the appropriate neurovascular pedicle structure should enable performing a successful flap transfer. [ABSTRACT FROM AUTHOR]

Background This study aimed to elucidate the potential usefulness of the medial rectus muscle of cadavers for research on satellite cells. Methods Twenty-four medial rectus muscles were obtained from 12 cadavers. The control group included six medial rectus muscles from three live adults without brain activity. The muscle fiber diameter and distribution of satellite cells were measured and compared. Immunohistochemistry for myosin heavy chain and the transcription factor PAX7 was performed, and the distributions of myocytes and satellite cells were evaluated. Results The average muscle fiber diameter was 142.18±36.49 μm in the cadaver group and 149.34±15.26 μm in the control group, and there was no significant difference between the two groups (p=0.38). The ratio of PAX7(+) cells to the number of muscle fibers was 0.056±0.015 in the control group and 0.006±0.006 in the cadaver group, reflecting a significant difference (p

Abstract Background Regional anaesthesia education, especially for ocular procedures, necessitates reliable surgical training models. While cadaveric models offer anatomical fidelity, conventional embalming methods may compromise tissue integrity. We aimed to assess the effectiveness of Thiel cadavers for training in sub-Tenon’s blocks by evaluating ocular tissues and measuring insertion forces. Methods Experimental design, using twenty eyes from ten Thiel cadaver heads. These cadavers were specifically prepared to test the administration of sub-Tenon’s blocks. The research was conducted in a controlled laboratory setting appropriate for handling cadaveric materials and conducting precise measurements. Each cadaver eye underwent an initial ultrasound examination, and its axial length was noted. An intravitreal injection of heptastarch solution followed, to re-establish the eye’s sphericity. After this volume injection, the axial length and intraocular pressure were measured again. Mock sub-Tenon’s blocks were administered in 2 separate quadrants of the eye, with insertion forces measured using a pressure gauge. These were compared to a data set of insertion forces measured in a series of isolated pig’s eyes on which STBs had been performed. Main outcome measurements were macroscopic assessment of the ocular tissue layers and the insertion forces required for the sub-Tenon’s blocks. In a second set of 10 Thiel cadaver heads, 5 ml of sodium chloride were injected as sub-Tenon’s blocks and the emergence of a periocular “T-sign” ascertained and measured by ultrasound. Results Four of twenty eyes (20%) retained near-natural sphericity, with the remaining requiring volume injection to approximate physiological shape and pressure. The conjunctiva and Tenon’s layer were intact, and correct cannula placement was achieved in all cases. In 16 of 20 eyes where T-signs could be measured, the median thickness of the T-sign amounted to 2.72 mm (range 1.34 mm–5.28 mm). The average maximum cannula insertion force was 2.92 Newtons. Insertion forces in intact Thiel cadaver heads were consistently higher than in isolated pig’s eyes (3.6 N vs 2.0 N). Conclusion These findings suggest that Thiel cadavers are a promising model for training in sub-Tenon’sblocks, despite the challenge of often desiccated and involuted eyes.

Objective: Intra-articular screw penetration is a probable complication of coronoid fracture fixation. Thepresent study aimed to determine the best radiography technique for visualizing the proximal radioulnar joint(PRUJ) space. Moreover, it aimed to determine the safe angle and length of the screw to avoid PRUJ penetrationduring coronoid fracture fixation.Methods: The Mimics software was used to construct a three-dimensional model of a healthy man’s forearmfrom a computer tomography scan. It was analyzed using the Solidworks software to determine the X-ray anglethat clearly showed the PRUJ space to detect penetration of screws from the coronoid process into the PRUJand determine the maximum screw angle and length that could be used without intra-articular penetration. Toverify these findings, a cadaveric study combined with radiographs was conducted.Results: To visualize PRUJ space, the optimal X-ray angle was 13º lateral to the perpendicular line when theforearm was positioned at full supination. If the coronoid process was segmented into zones 1 (closest to theradioulnar joint) to 4 (farthest from the joint), the screw could only be inserted at a right angle in zone 1. In zones2, 3, and 4, inclination angles less than 15, 35, and 60 would prevent intra-articular penetration, respectively.Conclusions: The X-rays could visualize the PRUJ space with an anteroposterior radiograph at an angle of13º ulnar deviation from the perpendicular plane. During coronoid process fracture fixation, shorter screwswith less lateral inclination were safer when inserting screws in the zones of the coronoid process adjacent tothe PRUJ.

Background Formaldehyde a commonly used embalming fluid for the preservation of cadavers, produces numerous short and long-term side effects on the students and staff working with it. Indoor plants have been shown to reduce atmospheric formaldehyde levels. The purpose of the study was to compare the efficacy of indoor plants in reducing formaldehyde levels in ambient air to levels deemed safe by WHO standards Methods The study was conducted in the storage room of the Anatomical dissection hall. 7 potted plants of one variety were kept in the storage room for 14 days and the Formaldehyde reading was measured using a VOC (Volatile Organic Compound) monitor. Then the same was done with no plant. This cycle was repeated 2 more times, with two different plant species. The three spieces of plants used for this study were as follows: Dracaena trifasciata, Epipremnum aureum, Spathiphyllum. Results The results were analysed and compared and it was determined that the effect of having a plant present versus having no plant present on the Formaldehyde concentration in the air was inconclusive as Dracaena trifasciata failed to reject the null hypothesis altogether (p-value>0.05), while Epipremnum aureum and Spathiphyllum rejected the null hypothesis (p-value Conclusion The efficacy of indoor plants in reducing formaldehyde levels in ambient air needs to be further explored and validated since all the prior studies conducted were in controlled environment and should be done in a real time scenario for its practical and beneficial uses.

Background Formaldehyde a commonly used embalming fluid for the preservation of cadavers, produces numerous short and long-term side effects on the students and staff working with it. Indoor plants have been shown to reduce atmospheric formaldehyde levels. The purpose of the study was to compare the efficacy of indoor plants in reducing formaldehyde levels in ambient air to levels deemed safe by WHO standards Methods The study was conducted in the storage room of the Anatomical dissection hall. 7 potted plants of one variety were kept in the storage room for 14 days and the Formaldehyde reading was measured using a VOC (Volatile Organic Compound) monitor. Then the same was done with no plant. This cycle was repeated 2 more times, with two different plant species. The three spieces of plants used for this study were as follows: Dracaena trifasciata, Epipremnum aureum, Spathiphyllum. Results The results were analysed and compared and it was determined that the effect of having a plant present versus having no plant present on the Formaldehyde concentration in the air was inconclusive as Dracaena trifasciata failed to reject the null hypothesis altogether (p-value>0.05), while Epipremnum aureum and Spathiphyllum rejected the null hypothesis (p-value Conclusion The efficacy of indoor plants in reducing formaldehyde levels in ambient air needs to be further explored and validated since all the prior studies conducted were in controlled environment and should be done in a real time scenario for its practical and beneficial uses.

The 7th cervical vertebra (C7) is described as having the most prominent spinous process (SP) and is characterized as the "vertebra prominens" (VP) of the cervical spine in anatomy textbooks. The VP is an important anatomical landmark of the neck for clinical examination and therapeutic intervention. The present study identifies the level of the most prominent SP of the cervical and uppermost thoracic vertebrae in a cadaveric cohort. Thirty-nine (23 female and 16 male) cadavers of a mean age of 77.5 years were investigated in a prone position and a certain cervical kyphotic bending. The most prominent SP, at the base of the neck, was palpated and marked with a wedging nail into the SP of the vertebra. The cervical region was dissected, and a blind investigator examined whether the nail was placed into the SP of C7 or the SP of another upper or lower vertebra. In 19 out of 39 cadavers (48.7%), the C7 was identified as the VP (typical anatomy), followed by the C6 (in 14 cadavers, 35.9%), C5 (in 4 cadavers, 10.3%). In 2 cadavers (5.1%) the first thoracic vertebra was identified as having the most prominent SP. Although C7 is described as the VP, in the present study the SP of C7 was the most prominent in less than 50%. The high variable projection level of the most prominent SP of the cervical vertebra holds great clinical significance for spine examination, neck surgery, and spinal anesthesia. [ABSTRACT FROM AUTHOR]

Objective: Complete resection is the curative treatment choice for recurrent gynecological malignancies. Laterally extended endopelvic resection (LEER) is an effective surgical salvage therapy for lateral recurrence. However, when a recurrent tumor occupies the ischial spine and sacrum, LEER is not indicated, and surgical salvage therapy is abandoned. Theoretically, complete resection of such a tumor is possible by additional pelvic bone resection along with the standard LEER. Nevertheless, owing to the anatomical complexities of the beyond-LEER procedure, 2 major issues should be solved: sciatic nerve injury and tumor disruption during pelvic bone amputation. To overcome these technical challenges, we applied a multidirectional beyond-LEER approach, a novel salvage surgical procedure, with an aim of demonstrating its technical feasibility. Methods: We created a simulation model of a laterally recurrent tumor that occupied the right ischial spine and sacrum in a Thiel-embalmed cadaver. Results: Multidirectional approaches, including laparoscopic, perineal, and dorsal phases, were safely applied. We laparoscopically marked the L4-L5-S1 complex and S2 nerve with different colored tapes, and by pulling them out into a dorsal surgical field, the sciatic nerve was safely preserved. The dissection lines of the multidirectional approaches were aligned using tapes as landmarks, and complete tumor clearance without tumor disruption was accomplished. By following the cadaveric training, the first laparoscopic-assisted beyond- LEER procedure was successfully performed in a patient with recurrent ovarian cancer. Conclusion: Using a Thiel-embalmed cadaver, we demonstrated the technical feasibility of a sciatic nerve-preserved beyond-LEER procedure, which was successfully performed in a patient with recurrent ovarian cancer. [ABSTRACT FROM AUTHOR]

Introduction While the 44-mm clay penetration criterion was developed in the 1970s for soft body armor applications, and the researchers acknowledged the need to conduct additional tests, the same behind the armor blunt trauma displacement limit is used for both soft and hard body armor evaluations and design considerations. Because the human thoraco-abdominal contents are heterogeneous, have different skeletal coverage, and have different functional requirements, the same level of penetration limit does not imply the same level of protection. It is important to determine the regional responses of different thoraco-abdominal organs to better describe human tolerance and improve the current behind armor blunt trauma standard. The purpose of this study was to report on the methods, procedures, and data collected from swine. Materials and Methods Live swine tests were conducted after obtaining approvals from the local institution and the Army Care and Use Review Office of the U.S. Department of Defense. Trachea tubes and an intravenous line were introduced before administering anesthesia. Pressure transducers were inserted into the lungs and aorta. An indenter simulating the backface deformation profiles produced by body armor from military-relevant ballistics to human cadavers was used to deliver impact loading to the liver region. A triaxial accelerometer was included in the indenter design. The animals were monitored for 6 hours, necropsies were performed, and injuries were identified. Biomechanical data of the energy, velocity, deflection, viscous criterion, force, and impulse variables were obtained for each test. Results Peak accelerations, velocities, deflections, forces, impulse, and energies ranged from 897 to 5,808 g, 21 to 59 m/s, 1.96 to 8.87 cm, 2.3 to 13.1 kN, 1.1 to 7.1 Ns, and 58 to 387 J, respectively. The peak viscous criterion ranged from 0.8 to 5.8 m/s. All animals survived the 6-hour survival period. Three animals responded with liver lacerations while the remaining 4 did not have any injuries. Conclusion The experimental design based on parallel tests with whole body human cadavers and cadaver swine was found to be successful in delivering controlled impacts to the liver region of live swine and reproducing liver injuries. Previously used biomechanical measures as potential candidates for injury criteria development were obtained. Using this proven model, tests with additional samples are needed to develop injury risk curves for liver impacts and obtain regional (liver) injury criteria. [ABSTRACT FROM AUTHOR]

Introduction Simulation-based medical training has been shown to be effective and is widely used in civilian hospitals; however, it is unclear how widely and how effectively simulation is utilized in the U.S. Military Health System (MHS). The current operational state of medical simulation in the MHS is unknown, and there remains a need for a system-wide assessment of whether and how the advances in simulation-based medical training are employed to meet the evolving needs of the present-day warfighter. Understanding the types of skills and methods used within simulation programs across the enterprise is important data for leaders as they plan for the future in terms of curriculum development and the investment of resources. The aim of the present study is to survey MHS simulation programs in order to determine the prevalence of skills taught, the types of learners served, and the most common methodologies employed in this worldwide health care system. Materials and Methods A cross-sectional survey of simulation activities was distributed to the medical directors of all 93 simulation programs in the MHS. The survey was developed by the authors based on lists of critical wartime skills published by the medical departments of the US Army, Navy, and Air Force. Respondents were asked to indicate the types of learners trained at their program, which of the 82 unique skills included in the survey are trained at their site, and for each skill the modalities of simulation used, i.e. mannequin, standardized patients, part task trainers, augmented/virtual reality tools, or cadaver/live tissue. Results Complete survey responses were obtained from 75 of the 93 (80%) MHS medical simulation training programs. Across all skills included in the survey, those most commonly taught belonged predominantly to the categories of medic skills and nursing skills. Across all sites, the most common category of learner was the medic/corpsman (95% of sites), followed by nurses (87%), physicians (83%), non-medical combat lifesavers (59%), and others (28%) that included on-base first responders, law enforcement, fire fighters, and civilians. The skills training offered by programs included most commonly the tasks associated with medics/corpsmen (97%) followed by nursing (81%), advanced provider (77%), and General Medical Officer (GMO) skills (47%). Conclusion The survey demonstrated that the most common skills taught were all related to point of injury combat casualty care and addressed the most common causes of death on the battlefield. The availability of training in medic skills, nursing skills, and advanced provider skills were similar in small, medium, and large programs. However, medium and small programs were less likely to deliver training for advanced providers and GMOs compared to larger programs. Overall, this study found that simulation-based medical training in the MHS is focused on medic and nursing skills, and that large programs are more likely to offer training for advanced providers and GMOs. Potential gaps in the availability of existing training are identified as over 50% of skills included in the nursing, advanced provider, and GMO skill categories are not covered by at least 80% of sites serving those learners. [ABSTRACT FROM AUTHOR]

Introduction Between 2011 and 2014, the Combat Casualty Training Consortium research study sought to evaluate all aspects of combat casualty care, including mortality, with a special focus on the incidence and causes of potentially preventable deaths among American combat fatalities. This study identified a major training gap in critical airway management. Because of the high rate of morbidity and mortality associated with poor or incorrect airway management, an effort to address this training gap was necessary. Materials and Methods This experiment compared the training using the Advanced Joint Airway Management System, a novel high-fidelity airway simulator, relative to one of the most utilized simulators for endotracheal intubation (ETI) via a parallel group randomized control trial design. Before training, participants (n  = 19) attempted an ETI on a cadaver using direct laryngoscopy. Performance during the attempt was recorded and scored by trained blinded raters. Participants were then randomly allocated to either novel or conventional training. Post-training, participants completed a second ETI under the same parameters. Analysis was completed via 2 × 2 mixed analysis of variance for (1) ETI Score, (2) Errors, (3) Critical Failures, and (4) Duration, across both the pre- and post-training tests and between the two groups. Results A priori power analysis required a total sample size of 84 participants in this experimental design. Consequently, this study is under-powered to reach statistical significance. Scores for all trainees did improve with training, yet analyses did not reveal a difference in overall ETI score between the novel and conventional training group, at baseline or at the post-training test (P  = .249). Conclusion The Advanced Joint Airway Management System simulator presents a training effect that is comparable to the conventional training model. However, given this study's small sample size, these results must be considered preliminary and further research is merited to draw firm conclusions about its impact on trainee performance. Future studies engaging larger cohorts of trainees and exploring the other capabilities of the Advanced Joint Airway Management System (cricothyroidotomy, needle chess decompression) are needed to further examine the educational potential of this novel airway management training system. [ABSTRACT FROM AUTHOR]

Introduction The uses of on-demand, interactive tablet-based surgical training environments are of interest as potential resources for both the acquisition and maintenance of rarely performed, critical procedures for expeditionary surgical care. This study examined the effectiveness of a tablet-based augmented reality (AR) procedural training environment for lower leg fasciotomy with a cohort of novice surgical trainees in (1) procedural knowledge, (2) tablet-based procedural skills, (3) tablet-based procedural time, and (4) procedural performance on a cadaver. We hypothesized that engaging with the AR procedural training would increase procedural knowledge and tablet-based skills and procedural time. We hypothesized that the tablet-based AR training environment would be insufficient to acquire the ability to perform lower leg fasciotomy on a cadaver. Materials and Methods This study was approved as exempt by the Institutional Review Board at USU. Surgical interns, sub-interns, and independent duty corpsman (n  = 30) with no prior lower leg fasciotomy experience voluntarily participated. Tablet-based training activities included pre-training assessment, engagement with instruction, interactive procedural practice, and post-training assessment. Tablet-based knowledge assessment included 17 multiple choice questions covering concepts, reasoning, and judgment associated with the procedure. Tablet-based procedural completion and time were assessed within the training environment. Within 1 week of completing the tablet activities, participants were assessed by fellowship-trained trauma surgeons while performing cadaver-based lower leg fasciotomy. Statistical analysis included paired t -tests and effect size (Cohen's d). Statistical significance was set at P  < .05. Results Tablet-based AR procedural training significantly improved procedural knowledge (P  < .001), tablet-based procedural skills (P  < .001), and reduced tablet-based procedural time (P  < .002). Effect sizes were very large for tablet-based procedural knowledge (d  = 1.75) and skills (d  = 3.2) and small (d  = 0.42) for procedural time. There were no significant effects of procedural knowledge, tablet-based procedural skills, or time on cadaver-based performance. No participant was able to accurately and independently complete lower leg fasciotomy procedure on a cadaver. Conclusions Tablet-based AR procedural training improved procedural knowledge and tablet-based skills; however, those gains did not transfer to the ability to perform the procedure on a cadaver. The tablet's limited AR interface did not support the acquisition of requisite surgical technique, tissue handling, and decision-making in novice surgical trainees. Experienced surgeons may have different outcomes because their mature understanding of surgical constructs would allow extrapolation of abilities to other procedural contexts. Further investigation of the tablet-based training environments for surgical care is necessary before distributing such resources to support clinical readiness. [ABSTRACT FROM AUTHOR]

Background Perfused cadavers are viable training models for operating room surgical skills, increasing fidelity of vascular anatomy, dissection, and tissue handling. In addition, perfused cadavers may have benefits in military medical training environments with a focus on hemorrhage control and vascular access. Objectives We created a large-scale training exercise with perfused cadavers in three different environments and aim to share the curricular design and feedback from the exercise. Methods We conducted a 4-day simulation training exercise with 13 perfused cadavers in 3 different environments: hospital environment, the austere echelons of care environment, and a controlled-settings tent for hemorrhage control and needle decompression training. Through an anonymous online survey and an after-action review (AAR), we elicited feedback on advantages, disadvantages, costs, and comparison to models of porcine and fresh cadavers for procedures and existing courses. Results A total of 324 participants were trained with 13 perfused cadavers for over 4 days from a variety of specialties and on different procedures and surgical skills. Based on 130 respondents to the survey and the AAR, perfused cadavers were rated to have realistic arterial bleeding and bleeding control training. In addition, perfused cadavers provided increased realism and fidelity for surgical skills. There were disadvantages of logistical requirements, cleanup, costs, and mobility. Conclusion Perfused cadavers can be implemented effectively for hemorrhage control training, surgical and procedure skills, and even exercises in austere environments, but require significant logistical and planning considerations. The training value is maximized with a progressive curriculum from hemorrhage control iterations to more invasive surgical procedures, such as thoracotomy and exploratory laparotomy. [ABSTRACT FROM AUTHOR]

Purpose: In the context of medical literature, a significant lacuna exists in understanding median arcuate ligament syndrome (MALS). While clinical aspects are well documented, literature lacks a robust exploration of the anatomical relationship between the celiac trunk and the median arcuate ligament (MAL). Methods: Morphometric parameters, including the vertebral level of MAL origin, MAL thickness, celiac trunk (CeT) origin level, diameter, and distances between CeT/Superior Mesenteric Artery (SMA) and the MAL center were observed on 250 CT angiograms. Cadavers (n = 11) were dissected to examine the same parameters and histo-morphological examination of MAL tissue was done. Results: Radiological findings established average MAL thickness of 7.79 ± 2.58 mm. The celiac trunk typically originated at T12. The average distance between the celiac trunk and the MAL center was 1.32 ± 2.04 mm. The angle of the celiac trunk to the abdominal aorta was primarily obtuse. The average celiac trunk diameter was 5.53 ± 1.33 mm. Histological examinations revealed a diverse MAL composition, indicating variable mechanical properties. Conclusion: This study provides comprehensive morphometric data on the anatomical relationship between the MAL and the celiac trunk. In contrast to available literature which says the average MAL thickness of > 4 mm is an indicator of increased thickness, we observed much higher average thickness in the studied population. The findings contribute to a better understanding of normal anatomical variations which can serve as reference values for accurate radiological diagnosis of MALS. The histological examination revealed the heterogeneous nature of the MAL tissue composition, suggesting variable mechanical properties and functions in different regions. [ABSTRACT FROM AUTHOR]

Background: Regional anaesthesia education, especially for ocular procedures, necessitates reliable surgical training models. While cadaveric models offer anatomical fidelity, conventional embalming methods may compromise tissue integrity. We aimed to assess the effectiveness of Thiel cadavers for training in sub-Tenon's blocks by evaluating ocular tissues and measuring insertion forces. Methods: Experimental design, using twenty eyes from ten Thiel cadaver heads. These cadavers were specifically prepared to test the administration of sub-Tenon's blocks. The research was conducted in a controlled laboratory setting appropriate for handling cadaveric materials and conducting precise measurements. Each cadaver eye underwent an initial ultrasound examination, and its axial length was noted. An intravitreal injection of heptastarch solution followed, to re-establish the eye's sphericity. After this volume injection, the axial length and intraocular pressure were measured again. Mock sub-Tenon's blocks were administered in 2 separate quadrants of the eye, with insertion forces measured using a pressure gauge. These were compared to a data set of insertion forces measured in a series of isolated pig's eyes on which STBs had been performed. Main outcome measurements were macroscopic assessment of the ocular tissue layers and the insertion forces required for the sub-Tenon's blocks. In a second set of 10 Thiel cadaver heads, 5 ml of sodium chloride were injected as sub-Tenon's blocks and the emergence of a periocular "T-sign" ascertained and measured by ultrasound. Results: Four of twenty eyes (20%) retained near-natural sphericity, with the remaining requiring volume injection to approximate physiological shape and pressure. The conjunctiva and Tenon's layer were intact, and correct cannula placement was achieved in all cases. In 16 of 20 eyes where T-signs could be measured, the median thickness of the T-sign amounted to 2.72 mm (range 1.34 mm–5.28 mm). The average maximum cannula insertion force was 2.92 Newtons. Insertion forces in intact Thiel cadaver heads were consistently higher than in isolated pig's eyes (3.6 N vs 2.0 N). Conclusion: These findings suggest that Thiel cadavers are a promising model for training in sub-Tenon'sblocks, despite the challenge of often desiccated and involuted eyes. Key points: • Thiel cadaver eyes were evaluated as training model for sub-Tenon's blocks for the first time • The cadaver eyes were often involuted and required fluid injection to reproduce physiological bulbar tonus • The ocular tissues and anatomical layers were well preserved • T-signs as a hallmark of successful sub-Tenon's block can be ascertained in Thiel cadaver eyes • Dynamic insertion forces were measured during cannula placement and can be used as reference for future studies comparing haptics of different models by an objective measure-insertion force. [ABSTRACT FROM AUTHOR]

Mechanical asphyxiation has been a common method used to commit homicide, including femicide, throughout history. A recent report by the United Nations has shed light on the issue of misidentification and concealment of gender-related killings, which makes it difficult to effectively fight against it. Forensic pathologists are frequently asked to examine cases involving suspected asphyxia to determine whether other persons have been involved. Therefore, medicolegal experts must look for signs of occlusion of the oral/nasal orifices, compression of the neck, or specific signs such as the "facie sympathique". There are situations where the physical signs are not distinctive enough to diagnose asphyxia, especially in cases where the individual has limited ability to resist external compression. In such cases, judicial autopsies should include an anatomical dissection of the neck structures through a layer-by-layer progression. It is important to search for the Amussat's sign, e.g., as part of a Forensic Clinical Anatomy approach. Additionally, individual anatomical variations, age or artefactual modifications, must be considered for the correct interpretation of findings. Microscopic examinations could aid in the diagnosis by providing additional findings, and several attempts have been made to identify unique markers of asphyxia through various laboratory techniques such as biochemistry, radiology and miRNA studies. However, no single finding or method has been identified as definitive. In the future, biomedical-legal sciences will have to rely on scientific research and the retrospective case series to provide a scientific framework on which to base their hypothesis, giving weight to evidence in the trial. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to investigate the origin and course of the orbital fat arterial supply in the lower eyelid using traditional anatomy and three-dimensional computed tomography (CT). Methods: Twenty-seven cadaver heads were infused with mercury sulfide contrast media through the ophthalmic artery, maxillary artery, transverse facial artery, and facial artery. CT images were obtained after contrast agent injection, three-dimensional CT scans were reconstructed, and the cadaver heads were dissected. Results: Forty-five qualified hemifaces showed that the orbital fat arterial supply in the lower eyelid originates primarily from the inferomedial muscular trunk (IMT) of the ophthalmic artery and the orbital branch of the infraorbital artery. The medial branch of the IMT terminated at the medial fat pad (35.6%) or the orbital floor (64.4%). The lateral branch terminated at the inferior oblique (IO) muscle (28.9%) or the central and lateral fat pads (17.8%). In 53.3%, the lateral branch extended to the anterior part of the lateral fat pad and terminated in the orbital wall or the zygomaticoorbital foramina. The orbital branch of the infraorbital artery coursed between the orbital floor and the orbital fat, providing supply to the IO muscle, inferior rectus (IR) muscle, nasolacrimal duct, and orbital fat. Conclusion: This study elucidated the origin and course of the orbital fat arterial supply in the lower eyelid, which may help to avoid reducing the blood supply of the orbital fat pedicles during surgery. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

Introduction: Cadaver dissection in anatomy, a cornerstone of medical school education, has been replaced by digital technologies. This study aimed to determine the learning outcomes nursing students could achieve through cadaveric dissection practice (CDP). Methods: This scoping review was carried out using the checklist outlined in the Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews through August 2023. Articles from PubMed, ERIC, and CINAL were included. This scoping review included studies that focused on the learning effects of nursing students' experiences with cadaver dissection, written in English, and covered all study types. Results: The cadaveric dissection exercise resulted in a strong interest in the human body and a thorough understanding of anatomy and physiology. It also allows for creating an image of care for the patient before death, the meaning of existence after death, acceptance that death is not frightening, and an understanding of the afterlife. Furthermore, the cadaveric dissection exercise has been reported to improve confidence in patient care, lead to a better understanding of what other professions practice, and involve the development of professional identity. Conclusions: Studies on the learning effects of CDP have differed in subject matter and educational methodologies. In the future, while determining how the experience of CDP is related to nursing practice of nursing students and graduates, we must explore effective CDP and develop educational methodologies that can achieve similar learning effects. [ABSTRACT FROM AUTHOR]

Purpose: The anatomy of the extraocular rectus muscle insertions is clinically relevant in the field of ophthalmology. This descriptive cadaveric study determines the relative degree orientation of the superior, lateral, and inferior rectus muscles with respect to the medial rectus and investigates the distances between the rectus muscle insertions. Method: Thirty cadavers (50% female, mean age = 81.86 years, SD 12.16) were included for a total of 60 eyes. For each eye, a lateral canthotomy and cantholysis were performed followed by a peritomy. Muscle hooks were then used to access and isolate the rectus muscles. The degree orientation was determined by marking the muscle midpoints at insertion, using the center of the cornea as the vertex, and measuring the angle with the Angle Meter 360 application (© Alexey Kozlov) (Figure 1). The distances between rectus muscles were measured from the same muscle midpoints using calipers. Results: The degree orientations with respect to the medial rectus are displayed in Figure 2 and were as follows: superior rectus (mean = 93.14, SD = 3.04, min. 82.3, max. 100.3), lateral rectus (mean = 180.21, SD = 5.65, min. 170.5, max. 190.6), and inferior rectus (mean = 90.57, SD = 4.47, min. 84.0, max. 98.9). The distances (measured in mm) between rectus muscle midpoints at insertion included medial rectus to inferior rectus (mean = 13.64, SD = 0.54), inferior rectus to lateral rectus (mean = 13.79, SD = 0.75), lateral rectus to superior rectus (mean = 13.54, SD = 0.63), and superior rectus to medial rectus (mean = 13.83, SD = 0.75). The relative distances between the midpoints of the extraocular muscles observed in males versus females showed statistically significant differences in medial rectus to inferior rectus (13.8 vs. 13.5, p = .01), inferior rectus to lateral rectus (14.1 vs. 13.5, p = .03), and superior rectus to medial rectus (14.0 vs. 13.5, p = .04), respectively (Table 1). Conclusion: This is an important study of the extraocular muscle degree orientation performed with an innovative measuring approach. The degree orientation of the insertions relative to the medial rectus may have surgical application in the field of ophthalmology. [ABSTRACT FROM AUTHOR]

The intranasal route enables direct delivery of multiple substances from the nose to the brain, through olfactory and trigeminal pathways, bypassing the blood–brain barrier and avoiding systemic absorption. Despite the potential of this route, the various administration approaches make data reproducibility and interpretation challenging, emphasizing the necessity to establish a consistent methodology. Considering this, the aim of our study was to assess and compare the distribution of two dye volumes (30 µl and 50 µl) in the nasal cavity of rat cadavers. We employed three distinct methods of intranasal delivery: nose drops, by pipette tip, or cannula inserted into the nasal cavity. The results indicated that for both volumes, using the nose drops and the pipette tip methods, the dye dispersion occurred mainly in the vestibule, respiratory and olfactory regions, without reaching the olfactory bulbs. Using the cannula method, the deposition predominantly occurred in the respiratory and olfactory regions, with the dye reaching 66.7% and 100% of the olfactory bulbs, respectively, to low and high volume. Furthermore, the results demonstrated differences between the two volumes, in the pharynx, larynx, trachea, septal window, and incisive papilla, where an increased dye presence was observed with the 50 µl instillation across all three methods. According to our results, the intranasal delivery with a cannula was the most effective method for dye deposition in the olfactory region. However, further studies in live animals will be necessary to determine and refine the administration method that consistently allows specific deposition in the olfactory system. [ABSTRACT FROM AUTHOR]

Background: Approximately 40% of chronic low back pain patients have a discogenic origin. In relation to intervertebral disc injuries, most of them are in the posterior and lateral zone of the disc, involving the anterior lumbar roots and the spinal cord. Objective: The objective was to analyze and describe the accuracy and safety of a new ultrasound-guided approach to target the posterolateral part of the intervertebral lumbar discs in cadaveric specimens. Methods: A cross-anatomical study on sixty cadaver intervertebral lumbar discs was performed. A needle was introduced in the posterolateral part of the discs using ultrasound guidance. A transducer was placed in the anterior abdomen to visualize the discs in cross-section as well. A dissection of the specimen was performed to visualize the final position of the needle tip and its distance from the main lumbar structures. The angulation, length, and distance of the needle from the vertebral spine, the relevant ultrasound anatomical references, and the accuracy of the procedure were evaluated. Results: The needle tip reached the posterolateral part of the discs in 93.3% of the attempts. The mean length of the needle inserted was 79 ± 15 mm, the angulation 129 ± 20.2°, the distance from the spinous process was 77 ± 19 mm, and the distance of the needle to the nerve roots was 2.0 ± 1.2 mm. No statistically significant differences between genders were found. Conclusions: An ultrasound-guided technique can be an accurate and safe technique to perform invasive procedures on the posterolateral part of the intervertebral lumbar discs. [ABSTRACT FROM AUTHOR]

Insertional Achilles tendinopathy (IAT) is a common pathology with multiple surgical interventions available for treatment. The Zadek, dorsal closing wedge calcaneal osteotomy (ZO) has been demonstrated to be effective treatment of IAT. There have been various recommendations in the literature as to what measurement of wedge removal should be considered ideal to produce greatest postoperative range of motion (ROM), thus postoperative biomechanical potential. Accordingly, the purpose of this cadaveric study was to assess the range of motion achieved after various measurements of wedge removal by ZO. The ZO was performed on six cadaveric specimens. A 7.5 mm and 15 mm wedge osteotomy was marked and sequentially completed on each specimen. Lateral fluoroscopic imaging was utilized to take preoperative and postoperative ROM measurements for each osteotomy. Dorsiflexion (DF) and plantarflexion (PF) ROM arcs were measured for each wedge size and compared by t-test. Effect sizes were calculated by Cohen's d analysis. Maximal DF was 110.87 ± 12.97 deg in the pre-osteotomy state. Removal of a 7.5 mm wedge improved DF by 8 deg to a mean 102.93 ± 13.81 deg (p = 0.08). Removal of a 15 mm wedge improved DF by 16 deg to a mean 95.96 ± 11.41 deg (p = 0.003). Cohen's d and effect size calculation demonstrated a 7.5 mm wedge to have a small effect on DF, while a 15 mm wedge had a medium effect (0.29, 0.52 respectively). Maximal PF did not change significantly amongst the pre-osteotomy, 7.5 mm wedge, or 15 mm wedge positions. ICC was 0.96. Based on the results presented in this study, removal of a 15 mm wedge with ZO yields significant and greater improvement in ROM than a 7.5 mm wedge. We hope the current study will better inform preoperative planning for ZO. Prospective Cadaver Study. V. [ABSTRACT FROM AUTHOR]

The superior cerebellar artery (SCA) is a vessel anterior to the brainstem, usually originating from the basilar artery (BA). In this case, a different course of left SCA in a 74-year-old male cadaver was reported. The origin of the SCA was found to be a unilateral double root at the left side on the anterior surface of the pons. The distances of the starting points of roots to the bifurcation of BA were 31.09 mm on the right side, on the left side the rostral root was 33.84 mm and the caudal root was 30.95 mm. The diameter of the right SCA was 2.37 mm, the left rostral root was 2.05 mm and the caudal root was 1.24 mm. Knowing the course of SCA, and especially morphological variations, will be helpful for the clinical branches in preventing complications during surgical operations, evaluating angiographic examinations, and diagnosing and treating neurovascular diseases. [ABSTRACT FROM AUTHOR]

Most health-related educational programs are traditionally stressful. One of the most frequent academic stressors that students report is their gross anatomy experience. A variety of symptoms, including stress, anxiety, and emotional distress, have been reported among students in anatomy, particularly concerning working with anatomical donors. However, the literature remains sparse concerning what other stressors could contribute to the experiences of students in a donor-based anatomy course. Reports of stress are also common among students in non-donor dissection-based courses. This study aimed to investigate what stressors occupational and physical therapy students experienced in both the laboratory and lecture components of their anatomy course. A thematic analysis based on a descriptive phenomenological study was designed. This allowed the exploration of anatomy-related stress from the students' perspective as a phenomenon they experienced during their study. Thematic responses were categorized into laboratory and non-laboratory anatomy-specific stressors. Themes included dissection supervision, dissection group dynamics, emotional preparation, fear of death, condition of anatomical donor, anatomical donor's subcutaneous tissue, quality of dissection, previous anatomy experience, anatomical terminology, amount of information, teaching styles, fear of failure, self-directedness, and time constraint. Most stressors pointed to a course or curriculum issue and could be potentially modifiable. Knowledge of these stressors that students face could contribute to understanding the challenges in the study of anatomy from the student's perspective and contribute to future efforts in addressing these stressors. [ABSTRACT FROM AUTHOR]

Case: An overall healthy 48-year-old man suffered a left foot mangled crush injury resulting in a post-transmetatarsal amputation and subsequently developing a painful neuroma on the plantar surface of the foot. To avoid the zone of injury, targeted muscle reinnervation was used to treat the neuroma by coapting the tibial nerve to the motor point of the flexor hallucis longus (FHL) muscle. At 1-year follow-up, the patient reported no pain at rest, returned to work, and could ambulate with an orthosis for 30 minutes. Conclusion: Rare tibial nerve coaptations to the FHL could serve as a treatment option for patients with neuromas in traumatic postmetatarsal amputation. [ABSTRACT FROM AUTHOR]