Anatomical Science International最新文献

This radiologic work aimed to display the alteration in the superior orbital fissure (SOF) morphology in the pediatric population with advancing age. This pediatric examination consisted of computed tomography images of 180 subjects (90 males/90 females) aged 1-18 years. The length (SOF-L) and width (SOF-W) of SOF were measured, and its shape was noted. SOF-L and SOF-W were measured as 16.04 ± 2.34 mm and 5.35 ± 1.01 mm, respectively. SOF-L was similar in infancy and early childhood periods, but then decreased up to postpubescent period. This measurement increased significantly in postpubescent period. SOF-W did not show important change from infancy period up to postpubescent period. After that, it increased significantly in postpubescent period. Seven configurations regarding SOF shape were observed: the straight type in 20.8% out of 360 SOFs, eight-shaped type in 12.2%, key-shaped type in 14%, racket-shaped type in 18.6%, narrow type in 7.2%, triangular type in 14.7%, and curved type in 12.5%. SOF shape was not affected by sex (p = 0.150) and side (p = 0.919). Linear functions were calculated as y = 16.310-0.028 × age for SOF-L, and as y = 4.886 + 0.048 × age for SOF-W. SOF-L showed an irregular pattern of first decreasing and then increasing, during the transition from 1 year to 18 years. SOF-W displayed an irregular pattern of increasing with advancing ages in children. Our linear functions representing the growth pattern of SOF in children may be useful to estimate SOF size.

The persistence of the median artery in adult life, a remnant of the early brachial artery in the embryonic stage, has been reported in many anatomical and clinical studies. Herein, we aimed to investigate the prevalence and origin of the median artery in cadavers. We examined 53 adult Japanese cadavers and carefully dissected 106 upper limbs, and the arterial systems in the forearms and hands were observed macroscopically. We found the palmar type of the median artery on 106 sides in 53 cadavers, and found that it passes through the carpal tunnel and forms the superficial palmar arch in the hand in only two cadavers. The antebrachial type, ending in the forearm before reaching the wrist joint, was detected on 63 sides in 44 cadavers. The proportions of the origins of the median artery examined in this study were as follows: originating from the common interosseous artery (CIA) on 15 sides (23%), anterior interosseous artery (AIA) on 9 sides (14%), ulnar artery (UA) on 16 sides (24%), and CIA–UA trunk on 26 sides (39%). None arose from other arteries in the upper limbs. Based on our results and the current theory on vascular development, we conclude that the term ‘persistent median artery’ must be strictly used for the one that arises from the arteries in the forearm except for the radial artery, and the presence of this ontogenetic remnant can be interpreted as paedogenesis in the human body. We also describe that the increasing trend in the incidence of the median artery since the nineteenth century, as pointed out by a few researchers, may represent ‘nearly neutral evolution’ at the phenotypic level in human populations.

Despite advancements in automatic approaches for histomorphometry analysis of peripheral nerves, manual and semi-automated methods are widely utilized. Standard software functions are often unsuitable for analysis due to their irregular shapes, especially in pathological conditions. This study aims to assess the reproducibility of nerves morphometric analysis and compare results obtained using both default and new alternative algorithms. Sciatic nerves from Wistar rats (untreated and after administration of intraperitoneal hydrargyrum chloride), previously embedded in resin, were used. Morphometric analysis (diameters, myelin thickness, g-ratio, and circularity) was conducted using ImageJ on semithin sections, with axon and myelin boundaries manually outlined. Default diameters were calculated as the mean of Feret diameters, with subsequent calculations for myelin thickness and g-ratio. The alternative approach estimated diameters based on the geometric center of axons, iterating through selected coordinates; myelin thickness was obtained using line equations. In the control group, inter-rater agreement was higher or within expected reliability (0.8 ± 0.05). However, in the experimental group, myelin thickness, g-ratio, and axon circularity showed lower agreement (0.66, 0.58, and 0.68, respectively) without visible patterns on Bland–Altman plots. The alternative approach did not reveal significant differences between approaches, except for g-ratio in the control group and fiber diameter in the experimental group (p < 0.05), with effect sizes of 0.29–0.30 and 0.19–0.20, respectively. This study highlights reduced agreement among investigators analyzing nerve fibers under pathological conditions, raising concerns about the current standard measurement methods. The proposed approach, based on a single geometric center, provides more natural estimations for irregular fibers, and can be implemented in automated nerve fibers acquisition systems.

The coxal bone is crucial for movement, stability, and childbirth. Although most morphometric studies estimate gender and age, ratio, correlation and index calculations, there are no studies on the golden ratios in the coxal bone. Inspired by this idea, we investigated the presence of the golden ratio in the coxal bones. In this study, 95 adult dry coxal bones were measured using a digital caliper. Morphometric measurements were conducted based on 18 identified parameters. 12 of these parameters were related to the distances between two points in various parts of the bone. New ratios were determined with those measurements. In our study, we detected a constant coefficient between the following lengths: anterior superior iliac spine (ASIS)- posterior superior iliac spine (PSIS) and anterior inferior iliac spine (AIIS)- posterior inferior iliac spine (PIIS), vertical and transverse diameters of the acetabulum (AC), ASIS-AC and AIIS-AC, PSIS-AC and PIIS-AC, ASIS-auricular surface and AIIS-auricular surface, ASIS-symphyseal surface and AIIS-symphyseal surface (respectively, 1.29, 1.05, 1.18, 2.32, 1.26, 1.32). In order to check the accuracy of this hypothesis, length of between AIIS-PIIS, transverse diameter of the acetabulum, length of between PIIS-AC, length of between AIIS-AC, shortest distance between AIIS-auricular surface, length of between AIIS-symphyseal surface were estimated with the help of new equations. We detected constant ratios between some lengths in the coxal bone. Estimated distances should be taken into account during surgical procedures to prevent complications. In this context, the constant ratios identified in our study will serve as a guide for surgeons.

Classically, a single renal artery supplies, and a single renal vein drains each kidney. The morphology and variations in the renal vascular structures are of great importance when performing any type of renal surgery. The present case describes a rare combination of renal vasculature variation in a formalin-fixed, Chinese male cadaver. In this case, the left kidney is drained by a main renal vein (MRV) and an inferior renal vein (IRV), the latter might be the remnant of the left dorsal renal vein during the embryonic period. Two sets of renal arteries are present in this case, possibly due to persistent mesonephric arteries during embryonic development. Describing such anatomical variations is not only of academic interest but also important to help radiologists with the correct interpretation of image examinations and for surgeons to be prepared in advance.

This case study aims to elucidate the rare occurrence of bilateral internal carotid artery agenesis combined with a bovine aortic arch. The main objectives are to explore the incidence, embryological origins, clinical manifestations, and associated anomalies of this unique vascular condition. The study involves a detailed investigation of a 55-year-old male with a history of recurrent transient ischemic attacks (TIAs) using MRI and CT scan. The patient's medical history, clinical examination, and imaging results were systematically analyzed to provide a thorough understanding of the anatomical variations. The main findings include the rare coexistence of bilateral ICA agenesis and a bovine aortic arch, making this the 39th documented occurrence of bilateral ICA agenesis and the first recorded instance of its association with a bovine aortic arch. Also, the study highlighted the demographic characteristics, clinical presentations, and associated anomalies observed in the 38 documented cases of bilateral internal carotid artery agenesis. This case report contributes valuable insights into the rarity of bilateral internal carotid artery agenesis and its unprecedented association with a bovine aortic arch. The findings emphasize the importance of heightened anatomical awareness in clinical practice, particularly. Recognizing and understanding such variations is crucial for accurate diagnosis, appropriate management, and improved patient outcomes. Further research in this area is warranted to deepen our understanding of these complex vascular anomalies.

The plantaris muscle consists of a small muscular and a long tendinous part and is located at the superficial compartment of the posterior leg. The purpose of the current cadaveric report is to describe a rare variant of the plantaris muscle. During a routine dissection, a three-headed plantaris with two accessory heads was identified with a variant insertion of the two accessory heads. All heads originated from the femur popliteal surface, independently the one from the other. The first head contributed to the long and thin calcaneal tendon, and the two accessory heads were mainly inserted via their musculoaponeurotic expansion into the medial femoral condyle. The plantaris muscle morphological variability has been extensively studied lately. The incidence of the two-headed muscle has been estimated at 1.6%, while the three-headed muscle corresponds to an even rarer variation. This is the third case reported in the English literature, while the insertion of the two accessory heads has never been described before.

Variations of the left renal vein can be in the form of circumaortic vein or renal collar, retro-aortic vein, additional renal vein, or multiple primary tributaries. We report a unique complex venous pattern of concomitant circumaortic and retro-aortic left renal veins associated with a fenestrated left renal artery. Two renal veins, anterior and posterior to the renal artery, originated from the renal hilum. The anterior vein was further divided into two branches. One branch passed through the fenestrated renal artery to continue as the anterior limb of the circumaortic vein. It received the suprarenal and gonadal veins and drained into the inferior vena cava. The other branch coursed posterior to the fenestrated renal artery and joined the posterior renal vein. The posterior renal vein was divided into two branches: one forming the posterior limb of the circumaortic vein, and the other continued obliquely downwards as the retro-aortic vein. Variations in the left renal vein have been implicated in several clinical conditions, such as varicocele and pelvic varices. It also plays a crucial role in renal transplantation, as the left kidney is often used as the donor organ. Even though many reports have been published on circumaortic and retro-aortic veins, the complex venous pattern associated with a fenestrated renal artery has not been reported previously.

The forearm extensor muscle and hand extensor tendons are composed of several structures with unique anatomy identified with high morphological variability. During a routine dissection of a 74-year-old donated male cadaver, the right hand was isolated for educational purposes. After carefully dissecting the structures, an accessory muscle was identified. The accessory muscle corresponded to the extensor digitorum brevis manus (EDBM) inserted into the extensor indicis (EI) tendon, which was typically identified. According to the current literature, this occurrence corresponds to a rare variant, with 0.36-0.38% prevalence between the cadaveric studies. Knowledge of the hand extensor musculature is essential for orthopedics and plastic surgeons operating in the region to avoid iatrogenic injury.

Previous studies have reported that the lateral meniscus (LM) has two regions, the popliteal hiatus area (PH) with a scarce blood supply and the roots with an abundant one. However, the description of its vascular anatomy remains insufficient. We hypothesized that the difference in the width of the meniscus hilum (MH) affects the scarcity and abundance of blood supply to the LM. The MH is a concept proposed by us and is the only site of entrance or exit of blood vessels and nerves associated with the meniscus. The purpose of this study was to provide a structural explanation for the disparity of blood supply to the LM using the concept of MH. Sixteen knees were examined to investigate the blood supply to LM. In most areas, the femoral joint capsule (FJC) and tibial joint capsule (TJC) continued to the cranial and caudal edges of the LM, respectively. In the roots, the FJC and TJC covered the femoral and the outer-femoral surfaces. In contrast, the FJC in the PH did not attach to the cranial edge and only the TJC there did to the caudal edge of the LM. Histochemical examination showed that the blood vessels enter the LM via the MH. In the PH, the MH at the caudal edge was extremely narrow; and in the roots, the MH on the outer-femoral surfaces was wide. The results suggest that the difference in the width of the MH affected the scarcity and abundance of blood supply to the LM.