Clinical Anatomy最新文献

The tendon of the long head of the biceps brachii (LHBT) contributes to shoulder joint stability, but can become a source of shoulder pain because of trauma or degeneration. Injection of local anesthetics into the biceps sheath (BS) is an effective treatment for managing anterior shoulder pain and is widely performed clinically; however, the accuracy of unguided injections remains low. This study aimed to clarify the anatomical characteristics of the BS and identify the optimal injection site to improve the accuracy and safety of unguided anterior shoulder injections. Eight 5% formalin-fixed cadavers (16 shoulders) and 1 Thiel-embalmed cadaver were examined at Kurume University School of Medicine. Morphological measurements and histological evaluations were performed on cadaveric shoulders. In addition, ultrasound examinations were performed on 28 shoulders from 14 healthy adults. Vascular distribution around the BS was evaluated using latex injection in the Thiel-embalmed cadaver. The mean BS length in cadavers was 36.2 ± 8.4 mm, and the mean width was 9.4 ± 1.2 mm; these were not significantly different than those in live subjects. Macroscopic observations confirmed continuity between the BS and the shoulder joint capsule. The anterior circumflex humeral artery ran along the lateral aspect of the LHBT, while the transverse humeral ligament was located approximately 23 mm proximal to the BS. The BS is continuous with the joint capsule, and injections into the BS allow intra-articular delivery of medication. The optimal injection site is approximately 1.5 transverse fingerbreadths distal to the superomedial edge of the greater tubercle and medial to the LHBT. This location minimizes the risk of injuring the anterior circumflex humeral artery and the extended tendon of the subscapularis muscle while improving the accuracy of needle placement.

Myofascial pain syndrome (MFPS) causes chronic shoulder pain. Supraspinatus and infraspinatus, rotator cuff muscles innervated by the suprascapular nerve, are commonly affected. Intramuscular botulinum neurotoxin (BoNT) injections near motor points (i.e., visible nerve branch entry sites used as a proxy for motor endplates) are an effective treatment for such pain. However, current techniques limit accessibility. This study aimed to develop a patient-specific, landmark-guided technique for BoNT delivery into supraspinatus and infraspinatus using scapular dimensions. Ten pairs of cadaveric shoulders (n = 20) were dissected to identify supraspinatus and infraspinatus motor points. Distances from scapular landmarks to these motor points were measured in two axes. These distances were correlated with scapular dimensions (height, spine length, width) using linear regression. Patient-specific predictive formulae were derived. For validation, landmark-guided methylene blue dye injections were performed on four additional shoulders using calculated coordinates. For supraspinatus, motor points were predicted using deltoid tubercle and root of the scapular spine (r = 0.58-0.64, p = 0.0016-0.021). For infraspinatus, root of the scapular spine and lateral acromion were used (r = 0.46-0.60, p = 0.0054-0.0500). In all validation specimens, injected dye accurately reached the motor points. This study provides a validated, patient-specific, landmark-guided technique for BoNT delivery into the rotator cuff, offering an approach for accessible analgesia.

Understanding the anatomy of the medial canthal tendon (MCT) is essential for accurate facial reconstruction and orbital surgery. This study analyzed the morphometry and anatomical position of the MCT in 109 orbits from 55 Thiel-embalmed Scottish cadavers (27 males, 28 females; mean age at time of death 84.79 years). Measurements included bone-to-tendon, soft tissue, and bone-to-bone distances, with transverse lines established using a ruler at the superior and inferior orbital margins. Vertical distances from these lines to the MCT were recorded, alongside MCT length, width, and orbital height and width. A previously undocumented decussation pattern was observed in 7% of cadavers, in which the superior and inferior bands of the MCT crossed over the frontal process of the maxilla. The remaining specimens exhibited a single-band configuration. Statistically significant sex-based differences were found in four of seven parameters: the distance between the inferior orbital margin and MCT (p < 0.001), orbital height (p < 0.01), orbital width (p < 0.01), and frontonasal suture to MCT distance (p < 0.02). MCT length and width showed no sex differences. These findings establish the dacryon as a reliable landmark for MCT positioning and highlight the importance of population-specific anatomical data in surgical and forensic applications. This study offers novel insights into MCT morphology within a Scottish population, reinforcing the relevance of precise morphometric data for clinical accuracy.

Advanced large language models with multimodal capabilities offer potential new applications in medical education. This study evaluated GPT-4o's performance in normal histology image interpretation. We assessed GPT-4o's ability to interpret 120 histological images across four histological tissue types at three different magnification levels. Three histology experts evaluated responses using a 4-point rubric across three assessment criteria: tissue/organ identification, structure identification, and structure function assessment. Statistical analysis included ANOVA with Tukey tests, three-way ANOVA for interaction effects, Pearson's correlation, and ICC for reliability. GPT-4o achieved an overall mean score of 2.71 (SE 0.07), with 59.01% of responses rated "Good" or "Excellent." Performance varied significantly across tissues, with epithelial showing highest accuracy (mean 3.11, SE 0.06) and muscle lowest (mean 2.43, SE 0.07). Combined 3 magnifications yielded better results (mean 3.03, SE 0.07) than low magnification alone (mean 2.41, SE 0.07, p < 0.001). Tissue/organ identification questions received higher scores (mean 2.83) than structure identification (mean 2.65) and structure function assessment (mean 2.64). Inter-rater reliability was excellent (ICC = 0.89). GPT-4o demonstrates moderate histological interpretation ability, varying by tissue type and magnification level. The model performs best with multiple magnification views. These findings suggest potential use in medical education but indicate the need for instructors' supervision.

Intraoral ultrasonography (IOUS) is a simple, rapid, and safe imaging technique, yet its clinical use in the oral cavity has been limited due to the region's complex anatomy and the absence of standardized anatomical reference data. The floor of the mouth (FOM) contains the submandibular duct, salivary glands, vessels, and multiple muscles within only a few millimeters of soft tissue, making precise anatomical knowledge essential for diagnosis and safe surgical intervention. This study aimed to analyze IOUS patterns of the FOM to identify key anatomical structures and provide depth-based anatomical data that enhance the clinical applicability of IOUS. Using a 12 MHz intraoral linear transducer, ultrasonographic images were obtained from 84 sides in 42 volunteers (12 male and 30 female; mean age, 34.0 ± 12.5 years) at three standardized intraoral reference points. The key structures were visualized in real time using B-mode and Doppler imaging, and their depths from the oral mucosa were quantitatively measured. The submandibular duct was consistently observed at P1 and P2 and located superficially at approximately 2 mm. In contrast, the lingual and sublingual vessels were located much deeper (approximately 7-11 mm) and showed substantial variability. No significant differences were observed between sides, between sexes, or between arterial and venous depths. The arterial and venous depths showed considerable overlap, indicating a single "vascular layer," which closely corresponds to previously reported lingual nerve depths in cadaveric studies. These findings define an in vivo neurovascular corridor between the duct and vascular layer, providing critical guidance for safe surgical access. Overall, this study provides essential baseline data for the IOUS anatomy of the FOM, which can improve diagnostic accuracy and guide safer minimally invasive procedures in clinical practice.

Embryologically derived from foregut buds, the liver and pancreas are anatomically distinct and have discrete functions. However, for surgeons undertaking dedicated work in the hepato-pancreato-biliary region, realizing the analogy of their gross anatomy can be meaningful, even though it has not been widely noticed and discussed. In this article, we describe the anatomical similarities between these two organs, which can aid in performing certain forms of major hepatectomy and pancreatic resections. The pancreas comprises of a head with an uncinate process extension, a neck, a body, and a tail. The "C" loop formed by the neck, head, and the uncinate process of the pancreas encloses the superior mesenteric/portal vein (SMV/PV) and the superior mesenteric artery (SMA). The gross pancreas anatomy is similar to the gross anatomy of the liver. The right lobe of the liver extending to the caudate lobe (CL) is analogous to the head and the uncinate process, segment 4 is analogous to the neck of the pancreas, and the body/tail of the pancreas is analogous to the left lateral sector. Similar to the SMV and SMA, enclosed in the "C" loop of the pancreas, the common hepatic duct, portal vein, and right and left hepatic arteries are enclosed in the "C" loop of the liver, formed by segment 4, the right hemiliver, and the CL. The inferior vena cava and abdominal aorta are related to the posterior surface of the "C" loop of the right liver and pancreas. Our observation of the anatomical analogy between the pancreas and the liver can be used to simplify the teaching of gross anatomy, which could enhance understanding of the spatial anatomy of the liver and pancreas in an easy, faster, more memorable, and longer-lasting manner. The described anatomical analogies can also aid in conceptualizing and decoding the topographic complexities of major liver and pancreatic surgeries for budding and advanced surgeons.

There has recently been discussion regarding the term "clinical anatomy": how can it be defined, and what makes an anatomist "clinical"? Is there any difference between "anatomy" and "clinical anatomy"? What makes an anatomist "clinical" as opposed to being simply "an anatomist"? With the wide range of educator backgrounds now teaching anatomy in higher education institutions, it is highly relevant to ask this question. In this Viewpoint article, members of Council of The British Association of Clinical Anatomists (BACA) discuss these issues in relation to anatomical education in the UK. We acknowledge that anatomy education in the UK has undergone significant changes, which reflect broader changes in medical education. BACA's approach of including members regardless of whether or not they hold clinical qualifications, while maintaining rigorous healthcare-related standards, aligns with the perspective that the clinical anatomist is defined not by credentials alone, but by a commitment to collaborate with other healthcare disciplines, integrating anatomical knowledge with clinical relevance.

The claustrum is a thin gray matter structure with extensive cortical connections, involved in mechanisms of consciousness and salience processing. Numerous studies have suggested that the claustrum may play an important role in neurodegenerative diseases. In this work, we aimed to review and summarize current evidence on the involvement of the claustrum in neurodegenerative disorders. Our review was conducted following PRISMA 2020 guidelines using databases including Google Scholar, MEDLINE, and Scopus. A total of 2316 studies were screened, and 135 were included in the full-text analysis, focusing on claustral structural changes, connectivity alterations, and their impact on clinical symptoms in neurodegenerative diseases. A total of 30 studies met the inclusion criteria. The strongest pathological evidence of claustral involvement was observed in Parkinson's disease and dementia with Lewy bodies and Alzheimer's disease. Claustral abnormalities were also reported in frontotemporal dementia, in poststroke patients, and in multiple sclerosis. Alterations of the claustrum correlated with clinical symptoms such as cognitive impairment. The claustrum is a structure involved in multiple neurodegenerative disorders. As a network node between cortical regions, it is critically involved in numerous neurodegenerative disorders.

Digital anatomy platforms are used in undergraduate healthcare education, but their integration into early curricula varies and often lacks alignment with instructional design. This study evaluates the implementation of Complete Anatomy, a three-dimensional anatomy platform, within an early-year medical curriculum. A mixed-methods design was used to collect student and staff data through surveys and focus groups. Student responses showed selective use focused on visualization tools, with limited engagement with quizzes and annotation features. Staff reported low familiarity and minimal use in teaching. Reported barriers included technical instability, navigation difficulty, and lack of integration with learning outcomes. Students and staff proposed curriculum actions to support platform use, including onboarding during induction, guided tasks in tutorials, tutor modeling, and alignment with block content. These actions respond to operational constraints and support structured adoption. The findings provide a framework for platform-specific implementation that may improve consistency of use and reduce cognitive burden. This approach supports integration of digital anatomy tools into early medical education and may inform institutional strategies for resource adoption across disciplines.

Fascia has historically been viewed as passive connective tissue packaging, but emerging evidence suggests a more complex and integrated role. We propose a theoretical mechanometabolic framework that conceptualizes fascia as reticulated, sheet-like structures investing micro- and macro-environments with dynamic components including blood, lymph, cerebrospinal fluid, and adipose tissue. This framework synthesizes evidence from embryology, biomechanics, cellular biology, and systems physics to suggest fascia functions as an active mechanosensitive network. While certain aspects of this framework, including fasciacyte identification and viscoelastic properties, are experimentally validated, others, such as critical phenomena, phase transitions, and comprehensive mechanometabolic integration, remain theoretical and require direct experimental validation. Clinical applications, particularly hydrodissection techniques that exploit fascial plane architecture, provide indirect support for discrete mechanometabolic compartmentalization, though mechanistic understanding requires further investigation. This manuscript presents both established findings and testable hypotheses, proposing experimental pathways to validate this integrative framework. Understanding fascia as a mechanometabolic system may have implications for anatomy education, manual therapy, surgical technique, and our broader conceptualization of human physiology.