Prevalence of the Onodi cell in the Polish adult population: an anatomical computed tomography study.

BACKGROUND: Onodi cell is a posterior ethmoid air cell with the optic canal bulging into it; the common position of the bulge is into the sphenoid sinus, usually immediately posterior to the posterior ethmoid air cells. Variable pneumatisation patterns lead to various structures of lamellae and sinuses occasionally exposing important nerves and vessels, such as the optic and vidian nerves, internal carotid artery and cavernous sinus. In clinical practice, special imaging techniques are used to navigate through the paranasal sinuses and hence avoid injury to these structures. This study is aimed to determine the prevalence of the Onodi cell in the Polish population and compare it with other reported occurrences. MATERIALS AND METHODS: A retrospective analysis of 296 computed tomography (CT) scans of patients treated in Krakow, Poland, using a Siemens Somatom Sensation 16 spiral CT scanner. No contrast medium was administered. RESULTS: The Onodi cell was found in 31 out of the 296 patients, or approximately 10.5%, consistent with the majority of research reporting on Onodi variants. Additionally, there was one presentation of a bilateral Onodi cell in a male patient. No statistically significant difference was found between the male and female populations with a positive identification of the variant (p = 0.095, Chi2 test). CONCLUSIONS: This study helped approximate the Onodi variant prevalence of 10.47%, falling within a commonly reported range 8-14%. This gives clinicians and surgeons a better understanding of this variant's structure and significance, and therefore an opportunity to improve treatment outcomes and research.

A left circumflex aorta with a displaced thoracic duct in a 94-year-old male cadaver: a case report with discussion on embryology.

A left circumflex aorta (LCA) is an extremely rare variation of the thoracic aorta. It is distinguished by a retroesophageal descending aorta that subsequently travels down the right side of the thoracic vertebrae towards the aortic hiatus. Nonetheless, its embryological origin ought not to be overly generalised, but each case should be considered individually due to its unique vascular patterns. This study presents a description of a LCA in a 94-year-old male cadaver. The dissection revealed the descending aorta posteriorly from the trachea and oesophagus and then laterally on the right from the thoracic vertebral bodies. The branching pattern of the aortic arch was typical, so was the course of the left and right recurrent laryngeal nerves. However, the thoracic duct was placed on the right, and drained into the right internal carotid vein. Due to the normal appearance of the ascending part and the arch of the aorta, it is safe to presume that the variation originated from the persistent right dorsal aorta, with the retroesophageal part from the persistent left dorsal aorta. Detailed understanding of the variations of the thoracic aorta, and the anomalies associated with the LCA, can help to improve management of these conditions, and with that, improve patients' overall outcomes. Patients with a LCA, or another vascular ring, can either be asymptomatic or present with oesophageal and/or tracheal compression symptoms. Management of this anomaly consists namely of ligation of the patent ductus arteriosus/ligamentum arteriosum and aortic uncrossing.

Bilateral accessory head of the adductor longus muscle: an anatomical case study.

The adductor longus muscle, with its proximal origin at the pubic bone and distal at the linea aspera, is reported to be one of the most frequently injured groin muscles in contact sports, namely football or ice hockey. Notwithstanding, there is a scarcity of published works regarding the accessory heads of the adductor longus muscle in the existing literature, let alone the clinical significance of the said variant. The following study is a case report describing bilateral accessory heads of the adductor longus muscle in a 97-year-old female cadaver. A routine cadaveric dissection revealed two accessory heads on the right thigh and one on the left thigh of a donor with no known structural or pathological abnormalities of the proximal lower extremity. The anterior division of the obturator nerve provided nerve supply to the variants on both sides. The deep femoral, superficial external pudendal, femoral vessels were responsible for the vascular supply to the accessory heads of the adductor longus. Undoubtedly, extensive knowledge regarding the variant anatomy of the hip adductor muscles is of immense importance to physiotherapists and orthopaedists treating patients for their injury or complete tears. Nonetheless, there is little information regarding the accessory heads of the adductor longus in the existing literature (originating mostly from cadaveric studies) that requires further evaluation in vivo to assess whether this variant might have an impact on a patient's everyday life.

Extensor digitorum muscle tendon to the index finger from the extensor carpi radialis brevis: a cadaveric case report.

The forearm extensor compartment is known for its wide variability in terms of muscle origin, number of tendons and their distal insertion. The index finger on its dorsal aspect is the typical place of insertion of the two tendons of the extensor digitorum (ED-index) and of the extensor indicis. Being acquainted with their anatomy is of immense importance to orthopaedic surgeons in the treatment of e.g., de Quervain's syndrome. The current report presents a rare finding of the ED-index tendon arising from the extensor carpi radialis brevis (ECRB). A routine dissection revealed their fused course from the lateral epicondyle of humerus, though separate from the extensor carpi radialis longus. The ED-index muscle belly separated from the ECRB, 119 mm distal to the lateral epicondyle. The distal insertion point of the ED-index was located radially to that of the extensor indicis. The deep branch of the radial nerve and the recurrent interosseous artery supplied the ED-index. No other musculotendinous variations were encountered neither on the ipsilateral nor the contralateral upper limb of the cadaver. This study presents in detail a tendon of the ED-index arising from the ECRB, a knowledge that can be applied namely in the lateral epicondylitis treatment or approach to the ulnar nerve at the level of the elbow. Extensive depiction of both the proximal and distal attachment points of the muscles, their course and dimensions is indispensable to attain the best patient outcomes and avoid iatrogenic injuries.

A three-headed piriformis muscle: an anatomical case study and narrative review of literature.

The piriformis muscle (PM) is found in the gluteal region, exiting the pelvis through the greater sciatic foramen and dividing it into the suprapiriform and infrapiriform foramina. The piriformis works as part of the hip external rotator muscle group, and is responsible for rotation of the femur upon hip extension and abduction of the femur during flexion of the hip joint. The aim of the present report is to describe a very rare case of the primary three-headed PM. To the best knowledge of the authors, the said variant has not yet been described in the existing literature. The 71-year-old male formalin-fixed cadaver was subjected to routine dissection. After careful removal of the connecting tissue, three separate, primary heads of the PM were identified. The lower head of the PM arose from the middle part of the sacral bone; 87.56 mm long and 9.73 mm wide. The medial head was attached to the internal part of the posterior inferior iliac spine; 121.6 mm long and 20.97 mm wide. The upper head was attached to the external part of the posterior inferior iliac spine; 78.89 mm long and 23.94 mm wide. All heads converged into a common tendon which inserted onto the greater trochanter. The clinical importance of this work comes down to the fact that the aberrant PM may be the reason behind the piriformis syndrome and its associated symptoms. Moreover, knowledge regarding the variant anatomy of the PM is of immense importance to, e.g. anaesthesiologists performing computed tomography- or ultrasound-guided sciatic nerve injection for local anaesthesia, radiologists interpreting imaging studies, and surgeons, especially during posterior approaches to the hip and pelvis.

A computed tomography comprehensive evaluation of the ostium of the sphenoid sinus and its clinical significance.

BACKGROUND: The purpose of this research was to evaluate the size of the sphenoid sinuses' ostia, the distance between them and the distance between the medial margin of the ostia and the median line in the Polish adult population. MATERIALS AND METHODS: The analysis was undertaken as a retrospective study of 296 computed tomography (CT) scans of patients (147 females, 149 males) with no comorbidities in their sphenoid sinuses. The paranasal sinuses were investigated by using Spiral CT Scanner (Siemens Somatom Sensation 16), in the option Siemens CARE Dose 4D, without administering any contrast medium. Having obtained transverse planes, multiplans reconstruction tool was used in order to glean sagittal and frontal planes. RESULTS: The average size of both sphenoid sinus ostia was 0.31 cm for both genders (for females ranging from 0.1 to 0.5 cm and from 0.1 to 0.6 cm for males). The mean distance between both sphenoid sinus ostia was 0.6 cm for both genders (the range for females was 0.1-1.4 cm, whereas 0.1-1.8 cm for males). The average distance between the medial margin of the ostium and the median line was 0.32 cm for both genders (0.31 cm for females in the range of 0-0.9 cm and 0.32 cm for males in the range of 0-1 cm). CONCLUSIONS: Intraoperative identification of the sphenoid sinus ostia might prove difficult and their inadequate excision could lead to potential iatrogenic complications, hence detailed anatomical descriptions are still warranted in specific populations in order to perform safe and effective procedures.

Agenesis of the sphenoid sinus and a single sphenoid sinus: a computed tomography anatomical evaluation.

BACKGROUND: Sphenoid sinuses are pneumatic spaces within the body of the sphenoid bone. Their development begins in the prenatal life and continues until the adulthood. Agenesis of the sphenoid sinuses is a situation in which they are undeveloped. On the other hand, a single sphenoid sinus lacks the presence of the main septum, leading to the formation of a single antrum. Contemporary use of transnasal transsphenoidal approaches for the pituitary surgery, as well as functional endoscopic sinus surgery urges medical professionals to be well acquainted with the aforementioned variant. MATERIALS AND METHODS: Paranasal sinuses of 300 patients (150 females, 150 males) were evaluated using computed tomography, without the use of contrast medium. Inclusion criteria involved absence of any identifiable pathology within the sphenoid sinuses and age over 18 years. Subgroup analysis involved probing for potential sources of heterogeneity, namely gender. RESULTS: In the whole research material of 300 patients, agenesis of the sphenoid sinuses was noted in 1% of the patients. No statistically significant differences were noted between the absence of the sphenoid sinuses and gender (p = 0.999). A single sphenoid sinus was found in 0.33% of the patients. There were no statistically significant differences found between the presence of fully developed sphenoid sinuses and gender (p = 0.498). CONCLUSIONS: Both agenesis of the sphenoid sinuses and a single sphenoid sinus are rare anatomical variants. Adequate planning for transsphenoidal surgeries with preoperative medical imaging is of essence in order to perform a safe and quality procedure.

An anatomical investigation of rare upper limb neuropathies due to the Struthers' ligament or arcade: a meta-analysis.

BACKGROUND: The Struthers' ligament (SL) is a fibrous band that originates fromthe supracondylar humeral process and inserts into the medial humeral epicondyle, potentially compressing both the median nerve and brachial artery. The controversial Struthers' arcade (SA) is a musculotendinous band found in the distal end of the arm that might compress the ulnar nerve. This study aimed to evaluate the pooled prevalence estimate of the SL and SA, and their anatomical features. MATERIALS AND METHODS: A meticulous search of major electronic medical databases was carried out regarding both structures. Applicable articles (and all relevant references) were analysed. Data from the eligible articles was extracted and evaluated. The quality and the potential risk of bias in the included studies were assessed using the AQUA tool. RESULTS: The arcade was reported in 13 studies (510 arms), whereas the ligament in 6 studies (513 arms). The overall pooled prevalence estimate of the ligament was 1.8%, and 52.6% for the arcade. Most frequently, the ulnar nerve was covered by a tendinous arcade (42.2%). In all cases, the ligament inserted into the medial humeral epicondyle, but had various origins. Only 1 study reported compression of the median nerve by the ligament, whilst another contradicted this view. CONCLUSIONS: Although the SL is rare, and the SA is a valid anatomical entity (though with a variable presentation), clinically meaningful neurovascular entrapments caused by these structures are infrequent. Nonetheless, a better understanding of each may be beneficial for the best patient outcomes.

Extensive pneumatisation of the sphenoid bone: anatomical investigation of the recesses of the sphenoid sinuses and their clinical importance.

BACKGROUND: There is a great variance between the extents of pneumatisation of the sphenoid sinuses that can reach beyond the body of the sphenoid bone. The purpose of this study was to find the prevalence of the recesses of the sphenoid sinuses in Polish adult population. MATERIALS AND METHODS: Two hundred ninety-six computed tomography (CT) scans of patients who did not present any pathology in the sphenoid sinuses were evaluated in this retrospective analysis. Spiral CT scanner (Siemens Somatom Sensation 16) was used to glean the medical images. Standard scan procedure was applied, with Siemens CARE Dose 4D option enabled. No contrast medium was administered. RESULTS: In the majority of the patients (93.92%), the pneumatisation of the sphenoid sinuses expanded beyond the body of the sphenoid bone; hence, there were recesses of the sinuses present. The most common variant was the presence of two recesses - 12.84% of cases. The prevalence of all the 17 recesses was only 0.34%. Amongst the uneven recesses present, the sphenoidal rostrum's recess (61.15% of the patients) and the inferior clinoid recess (56.42%) were the most common. Amongst the even recesses present, the lateral recess was prevalent in the majority (65.88%), whereas the posterior clinoid process' recess was the least common (9.8%). CONCLUSIONS: Presence of the recesses might facilitate access to the cranial fossae; hence, comprehensive evaluation of the sphenoid sinuses is of immense importance in order to avoid unnecessary drills through the hard bone, which could potentially damage the nearby neurovascular structures.

Protrusion of the carotid canal into the sphenoid sinuses: evaluation before endonasal endoscopic sinus surgery.

BACKGROUND: Many reports have previously indicated the vast number of anatomical variations of the sphenoid sinuses, e.g. presence of the recesses. Notwithstanding, there are a few crucial neurovascular structures directly neighbouring with the sinuses. The following research aimed to evaluate frequency prevalence of the carotid canal's protrusion into the sphenoid sinuses in adult population. MATERIALS AND METHODS: Computed tomography (CT) scans of the paranasal sinuses of 296 patients (147 females, 149 males) were analysed in this retrospective study. The patients did not present any pathology in the sinuses. Spiral CT scanner Siemens Somatom Sensation 16 was used in the standard procedure in the option Siemens CARE Dose 4D. RESULTS: Protrusion of the carotid canal was found in the majority of the patients - 55.74%, more frequently in males (65.1% of the patients) than in females (46.26% of the patients). The said variant - regardless of gender - was noted more often bilaterally (41.55% of the cases: 29.93% females, 53.02% males) than unilaterally (14.19% of the cases: 16.33% females, 12.08% males). In the unilateral type (regardless of gender), the protrusion was more common for the left sphenoid sinus - 10.81% of the patients (12.24% females, 9.4% males) than for the right - 3.38% of the patients (4.08% females, 2.68% males). CONCLUSIONS: Complicated structure of the paranasal sinuses, derived from the high prevalence of their anatomical variations, may perplex routine surgical interventions. Henceforth, referral for a CT scan is imperative in order to abate the risks associated with an invasive procedure in the said region.

The Internal Cerebral Vein: New Classification of Branching Patterns Based on CTA.

BACKGROUND AND PURPOSE: The internal cerebral vein begins at the foramen of Monro by the union of the thalamostriate and the anterior septal veins. The lateral direct vein is its other major tributary. Numerous researchers have reported differences in internal cerebral vein branching patterns but did not classify them. Hence, the objectives of this study were to evaluate the anatomy of the internal cerebral vein and its primary tributaries and classify them depending on their course patterns using CTA. MATERIALS AND METHODS: Head CTAs of 250 patients were evaluated in this study, in which we identified the number and termination of the anterior septal vein and the lateral direct vein. The course of the lateral direct vein and its influence on the number of thalamostriate veins and their diameters and courses were assessed. The anterior septal vein-internal cerebral vein junctions and their locations in relation to the foramen of Monro also were evaluated. RESULTS: We classified internal cerebral vein branching patterns into 4 types depending on the presence of an extra vessel draining the striatum. Most commonly, the internal cerebral vein continued further as 1 thalamostriate vein (77%). The lateral direct veins were identified in 22% of the hemispheres, and usually they terminated at the middle third of the internal cerebral vein (65.45%). The most common location of the anterior septal vein-internal cerebral vein junction was anterior (57.20%), with the anterior septal vein terminating at the venous angle. CONCLUSIONS: Detailed knowledge of the anatomy of the deep cerebral veins is of great importance in neuroradiology and neurosurgery because iatrogenic injury to the veins may result in basal nuclei infarcts. A classification of internal cerebral vein branching patterns may aid clinicians in planning approaches to the third and lateral ventricles.