Translational Research in Anatomy最新文献

Introduction

Identifiable superficial external landmarks can be used to determine the exact location of the internally located dural venous sinuses, for neurosurgical procedures. Several studies have been conducted to determine a standard method or a consistent reliable landmark, but all reported variations and inconsistencies with the examined landmarks. This study evaluated the relationship between the attachment site of the semispinalis capitis muscles on the external aspect of the skull and the internally located transverse dural venous sinuses.

Methods

Fifty-one South African skulls were used in this study. The Micro-focus X-ray Radiography and Tomography (MIXRAD) system at Necsa (Nuclear Energy Corporation South Africa) was used to scan and create three-dimensional images of each skull specimen. Pre-determined reference points were placed on the reconstructed images with the VGStudio Max volume rendering software. The relevant distances and locations of the reference points were measured and documented.

Results

The muscle attachment site was located inferior to the transverse sinuses in all the skulls with a mean distance of 15.99 mm (left side) and 19.43 mm (right side). A statistically significant difference was found between all the measurements comparing the left- and right sides, however, no such difference was found between males and females.

Conclusion

The apical attachment of the semispinalis capitis muscle is a good indicator for the internally located transverse dural venous sinus. This study indicates that a point of entry 8–10 mm inferior to this muscle attachment site be used, for safe access to the internal aspect of the posterior cranium.

Background

The abductor pollicis longus (APL) tendon exhibits significant anatomical variability, which is crucial for understanding its clinical implications in surgeries involving the thumb. While several studies have documented these variations in different populations, a systematic classification providing insights for surgical interventions targeting the thumb and its associated anatomical structures is rare.

Methods

This cadaveric study involved the dissection of 87 upper extremities from 44 embalmed cadavers (22 males, 22 females). The APL tendons were meticulously dissected, and the number of tendons slips and their insertion sites were recorded. Data were analyzed using Chi-square and Fisher's exact tests to assess differences in insertion sites between sexes and sides.

Results

The number of APL tendon slips distal to the first extensor compartment ranged from 1 to 5, with double slips being the most common configuration. The primary insertion site was consistently the base of the first metacarpal bone, observed in all specimens. Secondary insertion sites included the abductor pollicis brevis muscle (67.82 %), trapezium (17.24 %), opponens pollicis muscle (5.75 %), and proximal phalanx (2.30 %). Statistical analysis showed no significant differences in the insertion sites between sides and sexes. A new classification system for APL tendon slips was developed, categorizing them into three main types (Type I, II, III), and two minor types (Type IV and V), based on the number and insertion sites of the tendons. Type II with double tendon slips was the most prevalent (48.28 %). Symmetrical findings were found in 21 cases (48.84 %), with subtype IIb being the most common pattern.

Conclusion

This study highlights significant anatomical variations of the APL tendon in the Thai population, with important clinical implications for surgical planning and treatment of thumb-related conditions. The proposed classification system provides a structured framework for understanding these variations, aiding in the diagnosis and surgical management.

Background

The tendons within the soleus muscle are commonly utilized to delineate location of injury for soleus muscle strains. Strains within the soleus frequently involve the myotendinous (MTJ) or myofascial (MFJ) junctions, although spatial relationship between these tendinous structures are not well understood. This study aimed to structurally identify the MTJs and MFJs within the soleus as a starting point to understanding the distribution of connective tissue for further anatomical classification.

Methods

Forty (n = 40) soleus muscles, representing left and right sides from twenty (n = 20) formalin-embalmed cadavers (average age 78 years old; 10 males, 10 females) were dissected in-situ to analyze the distribution and orientation of the MTJs and MFJs within classified morphological variants. Muscles were cut in cross-section at three measured locations, proximal, middle, and distal, which allowed for analyzation of tendons through the course of the muscle. Additionally, anterior surfaces of morphological variants were visualized and reconstructed in three dimensions using a handheld blue light 3D scanner.

Results

The study revealed five morphological variants. Bipennate-Midline (n = 25), Bipennate-Medial Deviation (n = 6), Bipennate-Lateral Deviation (n = 3), Unipennate (n = 3), and Hypopennate (n = 3). Muscles included an anterior aponeurosis that was split into medial and lateral components, with each side made up of interconnections between the MTJ and MJF. The average width of the medial aponeurosis was greatest in the middle location, while the average lateral aponeurotic width decreased from proximal to distal. Regression analysis at the middle location revealed that 65 % of the change in width of the medial aponeuroses is due to the width of the medial MFJ.

Conclusions

Proximal-to-distal interconnections between the lateral and medial anterior aponeuroses and their corresponding MTJs and MFJs likely play a role in soleus injury patterns, especially in morphological variants. Awareness of anatomical variations in the location and orientation of these tendinous relationships is crucial for understanding lesions on diagnostic imaging.

Background

The cardiac conduction system (CCS) initiates and propagates electrical impulses across the heart. Scientists of both sexes have played unprecedented roles in discovering the CCS and advancing our anatomical, electrophysiological, and molecular understanding of the CCS in health and disease. Here, we review the underrepresentation of women in cardiac research and global disparities in cardiacresearch, specifically CCS research.

Despite the invaluable contributions of women in advancing our cardiac understanding, sex disparities exist. There is a stark underrepresentation of women in cardiac academia, the cardiac industry, and cardiac-related associations globally. However, female researchers have played pivotal roles in expanding our anatomical and molecular understanding of the CCS. In addition to this sex disparity, there is a global disparity in the output and funding of cardiac research. Even though low- and lower-middle-income countries account for over half of cardiovascular deaths worldwide, they contribute to less than 3% of the global cardiovascular research output.

Aims

This review aims to provide insights into the roles women researchers have played in transforming the landscape of CCS research. It also aims to shed light on the global disparities in cardiac research. The main goals are to draw attention to women's innovative contribution to cardiac research, to provide initiatives to create equal opportunities for women in cardiac academia and industry, and to enhance global cardiac research.

Conclusions

This review shows that there are innovative contributions by women researchers in advancing our understanding of the anatomy, function, and physiology of the CCS. It also shows that there is an underrepresentation of women at various levels: in academia and industry. Furthermore, we describe the global disparities in cardiac research owing to various contributing factors, such as underfunding. This review provides valuable initiatives (such as conference invitations and research funding assessments) that could be implemented in order to create a more inclusive future in global cardiac research.

Background

Bharatnatyam is an Indian classical dance form that involves rhythmic barefoot tapping at varying speeds. The intense impact forces generated during this dance can result in biochemical alterations in the feet, potentially causing injuries to ligaments, tendons, and fascia. This can lead to changes in the structure of the foot over time. Therefore, this study was conducted to compare anthropometric measurements related to the medial longitudinal arch of the foot in non-dancer, mid-stage, and last stage Bharatnatyam dancers.

Methods

The study was conducted on 192 participants. They were divided into three groups: 1) Non dancers 2) Mid-stage Bharatnatyam dancers, and 3) Last-stage Bharatnatyam dancers. Each group consisted of 64 participants each. Various measurements were taken on both the right and left foot using a wooden platform, foot image, and footprint. Later the results were analyzed statistically.

Results

On comparing the parameters in non-dancers and mid-stage Bharatnatyam dancers it was found that all the parameters were found to be significant except right and left arch index. On comparing the parameters of mid-stage and last-stage Bharatnatyam dancers, it was found that none of the parameters showed significant value. On comparing the non-dancers and last-stage Bharatnatyam dancers, it was found that except right and left arch index all the parameters were found to be significant.

Conclusion

From the results of the present study, it can be concluded that there were significant changes in the arches of the foot between the non-dancers and mid-stage and last-stage Bharatnatyam dancers.

Background

Superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) are vital vascular structures supplying the majority of the intestinal tract. Despite their clinical significance, comprehensive morphometric studies combining traditional cadaveric dissection with modern imaging techniques are scarce in literature. This study aimed to provide a detailed morphometric analysis of the SMA and IMA using both cadaveric dissection and multi-detector computed tomography (MDCT) angiography.

Methods

The study utilized a dual approach, combining cadaveric dissection (30 formalin-fixed cadavers) and MDCT angiography (images from 50 patients). Measurements including stem lengths, diameters at origin, and distances from the aortic bifurcation were taken, along with assessment of vertebral levels of origin and branching patterns. Data from both components were analyzed using descriptive statistics.

Results

Key findings for SMA include: Mean stem length: 3.19 ± 0.72 cm (cadaveric) vs. 2.53 ± 0.53 cm (MDCT); Mean diameter at origin: 0.93 ± 0.22 cm (cadaveric) vs. 0.57 ± 0.10 cm (MDCT); Most common vertebral level of origin: Upper border of L1 (78 % of cases); Branching pattern variations observed in 23.3 % of cadaveric specimens, which included the origin of the inferior pancreaticoduodenal artery from the first jejunal artery, a common trunk for right colic and ileocolic arteries, and absence of middle colic artery. For IMA: Mean stem length: 3.61 ± 1.29 cm (cadaveric) vs. 3.41 ± 0.69 cm (MDCT); Mean diameter at origin: 0.50 ± 0.11 cm (cadaveric) vs. 0.26 ± 0.05 cm (MDCT); Most common vertebral level of origin: Upper border of L3 (40 % of cases). No variations observed in branching pattern.

Conclusions

The detailed measurements, frequency of variations, and comparison between traditional and modern assessment techniques offer a nuanced understanding of mesenteric vascular anatomy. This study bridges the gap between classical anatomical knowledge and contemporary imaging capabilities, potentially improving surgical planning, interventional procedures, and radiological interpretation.

Introduction

Sex estimation is challenging in cases where dismembered or non-intact skeletal remains are recovered. Therefore, the development of sex estimation standards using various bones that present with high recovery rates during forensic investigations, like the metatarsal bones, is needed. The usefulness of the dimensions around the metatarsal diaphyseal nutrient foramen in sex estimation has not been assessed in South African Africans (SAA), constituting the majority of the country's population.

Materials and methods

Five measurements around the nutrient foramen were taken from 995 metatarsal bones (first to fifth) from 200 individual skeletons (100 males, 100 females). Measurements subjected to direct and stepwise discriminant function (DFA) and logistic regression (LRA) analyses included the total length, distance from proximal end to nutrient foramen, circumference, and mediolateral and dorsoplantar diameters at the level of the nutrient foramen.

Results

The original classification accuracies for multivariable functions of the stepwise and direct DFA ranged from 75.1 to 80 % and 76–79.5 % respectively. The original classification accuracies for multivariable functions of the stepwise and direct LRA ranged from 76.3% to 79.5 % and 75%–80.5 % respectively. The cross-validation classifications showed a drop of 0–2% for DFA and 0.2–1.9 % for LRA. Overall breadth measurements showed better classification accuracies than length measurements and females were classified with higher accuracy rates than males.

Conclusion

The dimensions around the nutrient foramen of the metatarsal bones show sexual dimorphism in the SAA. The generated DFA and LRA functions produced high average classification accuracies which can be appropriate for use in sex estimation in forensic settings, especially when an isolated foot is recovered.

Introduction

The current imaging report describes a unique coexistence of the neck venous system morphological variants.

Methods

The imaging study of a 75-year-old male patient was isolated due to its unique venous system.

Results

An internal jugular vein (IJV) duplication (main-typical and accessory IJVs) was identified on the right side, coexisting with a facial vein (FV) drainage into the accessory IJV. On the left side, the external jugular vein (EJV) was draining into the IJV and the FV into the EJV. A transverse anastomosis of the EJV and anterior jugular vein (AJV) was identified.

Conclusions

The IJV duplication is a rare morphological variant, and its coexistence with other co-variants complicates the area's anatomy. Understanding these morphological variants is crucial for anesthesiologists and surgeons, as it can help prevent iatrogenic injury.

Background

Digital 3D visualisation tools have been increasingly used to supplement anatomy teaching with positive results reported in knowledge acquisition, 3D spatial understanding, and active student engagement. Despite their well-documented benefits, evidence of their learning effect on head and neck anatomy is limited.

Methods

This cross-over design study aimed to compare using Complete Anatomy (CA) and conventional methods (prosections and plastic models) to learn laryngeal anatomy. Fifty-four first-year dental and dental hygiene students were randomly assigned to a CA and a conventional group. Pre- and post-tests were used to compare groups' knowledge gains, and a feedback questionnaire was used to compare students' perceptions towards CA.

Results

Both groups improved significantly in the post-test compared to the pre-test (Cohen's d ≥ 0.8). The conventional group significantly outperformed their counterparts in total (Cohen's d = 0.57) and written questions (Cohen's d = 0.9). However, both groups performed equally in the identification questions. Question-based analysis shows that the CA group performed significantly better in the identification questions than in the written questions (Cohen's d = 0.51). Nearly half the students perceived the CA application as easy to use, and the same proportion believed CA assisted their learning of laryngeal anatomy.

Conclusion

This study provides further evidence of the effectiveness of CA in knowledge gain and anatomical recognition and supports its use as supplementary to anatomy education in general and head and neck anatomy in particular.

Introduction

The tensor fasciae suralis (TFS) is a non-typical skeletal muscle that develops from one of the hamstring muscles and attaches to the deep fascia of the posterior leg (i.e., crural/sural fascia). By spanning the popliteal region, TFS can present as an unsuspected mass, impinge contiguous neurovasculature, complicate surgical access to posterior knee, and strain under typical use of the lower limb. Despite the necessary clinical discussion TFS generates, information about comparative gross anatomy examination, magnetic resonance imaging (MRI), and functional analyses of TFS is scarce in the literature. Therefore, the objective of the present study is to present a comprehensive report of a left unilateral TFS with gross imaging, detailed anatomical descriptions, MRI, biomechanical analysis, comparative review of published TFS cases, and discussion of clinical implications.

Methods

A left unilateral TFS was discovered during routine human cadaver dissection. After initial discovery of its proximal segment, axial and sagittal T1-and T2-weighted MRI was performed to visualize the entire TFS and its relation to nearby structures. The entire TFS and contiguous anatomy were then dissected, carefully cleaned of extraneous fascia, and photographed in situ. Gross and microscopic architectural features of TFS were measured, and its maximal isometric force was calculated.

Results

The 13.4 cm long, 5.02 g muscular belly of TFS branched 27.2° from the long head of biceps femoris and inserted into the investing fascia of the gastrocnemius medial head via a prominent 2.6 cm × 4.8 mm x 0.5 mm tendon. Gross imaging and MRI showed TFS crossing over the common fibular, tibial, and medial sural nerves. Biomechanical analysis determined TFS to be capable of producing 8.10 N of force.

Conclusions

The course of TFS offers notable clinical discussion about distal motor and sensory loss resulting from compression-based lesions of the underlying nerves. MRI, paired with full gross imaging and biomechanical analyses, provides a catalog of comparative information on TFS that may aide in differential diagnosis of an unsuspected mass in the popliteal region and guide subsequent treatment.