Explore the vast range of titles available.

The two-headed brachioradialis (BR) muscle represents a rare anatomical variation. The present study aims to describe this variant and provide detailed morphometric documentation. The study was conducted during routine anatomical dissection of a formalin-fixed 92-year-old male cadaver in whom a two-headed BR muscle was identified in the right upper limb. Detailed dissection was performed, and morphometric measurements were obtained three times using a digital caliper, with mean values reported. The BR consisted of two distinct heads with separate proximal attachments on the humerus, with the upper head located more proximally than the lower head. Both heads merged into a common tendon at distances of 193.11 mm and 170.69 mm from their respective proximal attachments. The total lengths of the upper and lower heads were 297.70 mm and 276.42 mm, respectively. Each head was independently innervated by branches arising from the radial nerve before its division. This case represents a rare and comprehensively documented example of a twoheaded BR muscle. Awareness of such variations may be clinically relevant, particularly in surgical procedures, imaging interpretation, and neurovascular interventions involving the forearm.

The hepatic portal vein is the main vascular route responsible for collecting blood from the liver, spleen, pancreas, stomach, gallbladder, and intestines. Its key function is to metabolize the components acquired from the blood. The objective of this study was to analyze the characteristics of HPV variants and understand the possible clinical considerations that arise with them. The databases Medline, Scopus, Web of Science, Google Scholar, Cumulative Index to Nursing and Allied Health Literature and Latin American and Caribbean Literature in Health Sciences were researched until January 2024. Tree authors independently performed the search, study selection and data extraction. Methodological quality was evaluated with an assurance tool for anatomical studies. Pooled prevalence was estimated using a random effects model. A total of 31 studies met the established selection criteria. In this study, 21 articles were included for the meta-analysis with a total of 51,244 subjects. Of these 21 articles, the topics studied came mainly from Europe and Asia, with three (n = 554; 1.08%) and 11 articles (n = 50,090; 97.75%) respectively, also having six articles from North America (n = 442; 0.86%) and one from Africa (n = 158; 0.31%), discarding the articles from Oceania and South America. For the HPV trifurcation variant, it was 8% (CI = 7-10%). Apropos the right posterior portal vein variant, as the primary tributary from the main HPV, it was 7% (CI = 4-11%). About the right anterior portal vein variant originating from the left portal vein, it was 4% (CI = 1-6%). Finally, the prevalence of the isolated variants was 2% (CI = 1-3%). The knowledge of HPV and its anatomical variants is of utmost importance for both medical professionals and anatomists, as it is one of the vessels that collects blood from many important viscera found in the abdominal cavity, any structural alteration could be crucial in diagnosis and surgical procedures.

BACKGROUND: The sternocleidomastoid (SCM) muscle is a prominent feature of the neck related to significant neurovascular structures with major clinical relevance in head and neck surgery. Variations of its anatomy and course have been widely documented; however, anatomical variants of its insertion are considered a rare occurrence. The aim of this study is to present a considerably uncommon anatomical variation of the insertion of the sternocleidomastoid muscle, discuss the clinical implications of its presence and suggest a possible role in the treatment of facial palsy. CASE REPORT: We present a rare case of bilateral supernumerary insertions of the sternocleidomastoid muscle that we came across during routine dissection on a male cadaver of a Caucasian donor to the Department of Anatomy. Specifically, the right sternocleidomastoid ascended as a single muscle belly that gave rise to six distinct tendons which inserted into the superior nuchal line of the occiput, while the left sternocleidomastoid muscle formed four distinct tendons prior to insertion. CONCLUSIONS: Morphological variations of the sternocleidomastoid muscle are relevant for clinical, surgical and radiological approaches of the neck. To our knowledge, the present case is the second reported insertional variation of the sternocleidomastoid muscle with supernumerary tendons. Its potential role in the treatment of facial palsy as a split muscle flap is also discussed and confirmation in the setting of a clinical scenario is encouraged.

BACKGROUND: Anatomical variations of the external jugular vein (EJV) are important because of their notable implications for flap design and diagnostic procedures, including EJV cannulation. CASE REPORT: This case report describes a unique venous anomaly observed during dissection of the right posterior cervical triangle in an adult male body donor. Notably, the EJV terminated atypically by forming a venous loop with the transverse cervical vein. This loop comprised three segments: a proximal segment formed by the EJV, a distal segment formed by the transverse cervical vein, and an intervening midsegment. From the convexity of the loop, two veins arose, running parallel for approximately 2.5 cm before piercing the investing layer of the deep cervical fascia and draining separately into the subclavian vein (SCV). RESULTS: The first vein (V1) entered the SCV 1.77 cm distal to the clavicular head of the sternocleidomastoid muscle (SCM), while the second (V2) did so 2.57 cm distal to the same landmark. Additionally, the posterior external jugular vein (PEJV), an infrequent finding, was observed running along the anterior border of the trapezius muscle and draining into the transverse cervical vein instead of the EJV. The suprascapular vein, rather than opening into the EJV, drained directly into the SCV. CONCLUSIONS: These findings underscore the significance of acknowledging such rare venous variations to avoid potential complications during surgical procedures involving the neck region.

PurposeA deep knowledge of the variations of the posterior forearm musculature is crucial for assessing and diagnosing conditions in this region. Extensor indicis (EI) is one of the muscles in this region, which exhibits diverse anatomical variations. This report documents an extremely unusual form of the EI with an accessory head on the dorsum of the hand.MethodsDuring routine dissection, an extremely rare presentation of the EI was found in the left forearm of a 94-year-old female cadaver.ResultsThis unusual EI consisted of two muscle bellies. The traditional belly originated from the distal two-thirds of the ulna. The muscle became tendinous around the carpal area, distal to the extensor retinaculum. The tendon was subsequently joined by an accessory muscle belly originating from the distal radioulnar ligament. The EI tendon inserted onto the dorsal expansion of the index finger, ulnar to that of the extensor digitorum. The posterior interosseous nerve innervated the muscle.ConclusionHerein, we report an extremely rare form of the EI. To our knowledge, EI with an accessory head has only been reported rarely over the past 200 years. Moreover, our report appears to be the first case with photographic details of this anatomical variation. Clinicians should be aware of this variation for proper diagnosis and treatment.

Morphological and morphometric variants of the anterior communicating artery (AComA) have been described by multiple studies; however, a complete classification system of all possible morphological variants with their prevalence is lacking. The current systematic review with meta-analysis combines data from different databases, concerning the AComA morphological and morphometric variants (length and diameter). Emphasis was given to the related clinical implications to highlight the clinical value of their knowledge. The typical AComA morphology occurs with a pooled prevalence (PP) of 67.3%, while the PP of atypical AComA is 32.7%. The identified AComA morphological variants (artery’s hypoplasia, absence, duplication, triplication, differed shape, fenestration, and the persistence of a median artery of the corpus callosum- MACC) were classified in order of frequency. The commonest presented variants were the AComA hypoplasia (8%) and the anterior cerebral artery (ACA) fusion (5.9%), and the rarest ones were the MACC persistence (2.3%), and the AComA triplication (0.7%). The knowledge of those variants is essential, especially for neurosurgeons operating in the area. Given the high prevalence of AComA aneurysms, an adequate and complete classification of those variants is of utmost importance.

Purpose Various anatomical variations in the branching pattern of the external carotid arteries are known to occur with significant frequency and have been documented in published literature. The purpose of this case report is to document and discuss variations in the branching patterns of the external carotid artery as seen in an anatomical donor and determine the clinical relevance of these variations. Case presentation A routine dissection of an 89-year-old female anatomical donor, whose cause of death was reported as acute myocardial infarction and atherosclerotic heart disease, revealed variations in the branching patterns of both external carotid arteries. Bilaterally, the common carotid arteries bifurcated at the C4 vertebral level. On the left side, an occipitoauricular trunk originated 0.5 mm superior to the common carotid artery’s bifurcation, whereas, on the right side, an occipitoauriculopharyngeal trunk branching 0.8 mm superior to the bifurcation of the common carotid artery was observed before branching into an occipitoauricular trunk and ascending pharyngeal artery. Conclusion This case report reinforces previous publications on arterial branching patterns and the importance of imaging prior to procedures. Clinically, these variations may impact surgical approaches, endovascular procedures within the neck, and vascular pathology management.

Recently, the classical anatomy of the quadriceps femoris has been questioned after the publication of various morphological variations that differ from the classical description. Therefore, it is necessary to collect information to reach an agreement on its structure. For this, a systematic review was carried out using the Web of Science, PubMed and ProQuest scientific databases, obtaining a total of 29 papers finally included in the systematic review after being subjected to inclusion and exclusion criteria. The results obtained showed an important and variable prevalence of new configurations described, such as additional heads in the rectus femoris, a different origin of the vastus intermedius, various portions of the vastus lateralis, or the involvement of the vastus medialis in the patellofemoral musculature. For this reason, understanding the anatomy of the quadriceps femoris is a matter that has not yet been fully resolved, with high variability among people that must be studied prior to the application of an invasive and/or surgical procedure.

BACKGROUND: The sternalis muscle is a rare anatomical variant of the anterior thoracic wall musculature with clinical implications for diagnosis and surgery. However, bilateral sternalis variations with an asymmetric X-shaped crossing have rarely been documented. This study aimed to supplement anatomical data and provide a clinical reference by reporting such a unique case. MATERIALS AND METHODS: During routine anatomical dissection for medical education, a bilateral sternalis muscle variation was identified in a 70-year-old female cadaver. The muscle’s origin, insertion, morphology, and anatomical relationships were observed, photographed, and subjected to precise morphometric measurements. Results: The bilateral sternalis muscles exhibited asymmetric morphology and formed an X-shaped crossing superiorly with the sternocleidomastoid muscles. The right muscle originated from the 6th–7th costal arches, inserted near the sternoclavicular joint, and measured 8.56 cm (lateral margin) and 6.27 cm (medial margin) in length. The left muscle arose from the 7th rib and inserted lateral to the 5th sternocostal junction, with a lateral margin length of 4.43 cm and a medial margin length of 4.14 cm. The right muscle was significantly larger than the left. CONCLUSIONS: This bilateral asymmetric X-shaped sternalis variation partially conforms to the Jelev II2 classification but has distinct inferior attachment patterns. Clinically, it may mimic breast masses, interfere with electrocardiographic (ECG) readings, or complicate thoracic and breast surgery. Enhanced recognition of this variant through preoperative imaging is crucial to avoid misdiagnosis and optimize clinical outcomes.

Purpose The extensor digitorum longus (EDL) and fibularis (peroneus) tertius (FT), muscles of the anterior compartment of the leg, synergistically work to dorsiflex and evert the foot. The EDL additionally extends the lateral four toes, while the FT normally lacks this ability. Anatomical variations of the variably present FT are common, but infrequently involve the EDL. The FT has been known to give off additional accessory tendons which may alter its role in ankle and foot movement. Documentation of unique anatomical variations of the FT and EDL can assist not only anatomists, but clinicians and surgeons as well. Methods During routine cadaveric dissection, a rare and unique bilateral presentation of the extensor digitorum longus and fibularis tertius was discovered. Results The extensor digitorum longus was found to be missing its lateral-most tendon that would normally insert on the 5th digit. A large, overriding FT split into three tendons, with the medial-most tendon inserting to the phalanges of the 5th digit, effectively replacing the missing EDL tendon. All findings were present bilaterally. Conclusion To our knowledge, despite previous literature of unilateral presentations like this case, a bilateral EDL and FT variation as seen here has never been reported in humans. The use of accessory fibularis muscles in tendon graft procedures, especially the FT, makes awareness of leg anatomical variations critical for surgeons operating in the area. The present case is discussed alongside other documented anatomical variations, highlighting potential clinical implications for tendon grafting and preoperative imaging.