Overlapping stimulation of subthalamic nucleus and dentato-rubro-thalamic tract in Parkinson's disease after deep brain stimulation

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces tremor, rigidity, and akinesia. According to the literature, the dentato-rubro-thalamic tract (DRTt) is verified target for DBS in essential tremor; however, its role in the treatment of Parkinson's disease is only vaguely described. The aim of our study was to identify the relationship between symptom alleviation in PD patients and the distance of the DBS electrode electric field (EF) to the DRTt.

METHODS

A single-center retrospective analysis of patients (N = 30) with idiopathic Parkinson's disease (PD) who underwent DBS between November 2018 and January 2020 was performed. DRTt and STN were visualized using diffusion-weighted imaging (DWI) and tractography protocol of magnetic resonance (MR). The EF was calculated and compared with STN and course of DRTt. Evaluation of patients before and after surgery was performed with use of UPDRS-III scale. The association between distance from EF to DRTt and clinical outcomes was examined. To confirm the anatomical variation between DRTt and STN observed in tractography, white matter dissection was performed with the Klingler technique on ten human brains.

RESULTS

Patients with EF overlapping STN and DRTt benefited from significant motor symptoms improvement. Anatomical findings confirmed the presence of population differences in variability of the DRTt course and were consistent with the DRTt visualized by MR.

CONCLUSIONS

DRTt proximity to STN, the main target in PD DBS surgery, confirmed by DWI with tractography protocol of MR combined with proper predefined stimulation parameters may improve efficacy of DBS-STN.

Anatomy and morphology of iliolumbar ligament

PURPOSE

To address limited amount of available data and contradictory statements in published works 60 Iliolumbar ligaments extracted from 30 cadavers were examined to describe their insertions and morphology.

METHODS

The ligaments were removed during the standard autopsy procedures with a use of an oscillating saw, a chisel and a scalpel. The specimens were photographed before the extraction and measured alongside their anterior margin. Next, they were preserved in formaldehyde, stripped of other soft tissues and then examined, photographed and described.

RESULTS

The mean length of the ligaments was 31.7 mm. 44 specimens were described as single-banded, 13 as double-banded and 3 as other. In 24 cases costal process of L_V has been fixed to the iliac plate by short ligamentous bands. In 38 cases there was a thick fibrous membrane connected to the ligament. No legitimate insertions on L_IV vertebra were observed.

CONCLUSIONS

Typical iliolumbar ligament consists of a single ligamentous band. Most common variability of the ligament consist of two bands. In approximately 40% of cases the costal process of L_V can be additionally stabilized to the iliac plate by short, strong ligamentous bands. In 63% of cases a connection between the iliolumbar ligament and a fibrous membrane placed in the frontal plane, superiorly to the ligament, has been observed. There seems to be no convincing proof of existence of the insertion of the iliolumbar ligament on the L_IV vertebra.

A fully capable pianist with a congenital bilateral agenesis of extensor pollicis brevis muscle

A 28-year-old male musical student has been presented with visible inability of active abduction and extension of the thumbs in both hands beyond the neutral position. The student has not been previously diagnosed and claimed no history of trauma or surgical procedures in the area of hands and no family history of such disabilities. The student remained capable of playing on keyboard instruments on high level due to compensation by hyperextension of the interphalangeal joint of both thumbs and showed no increased frequency of the injuries or playing-related disorders. The ultrasound and magnetic resonance imaging showed complete bilateral agenesis of extensor pollicis brevis muscles and was classified as isolated congenital clasped thumb syndrome. Due to the age of the student and the agenesis of the muscles the conservative treatment was deemed inadequate and due to high functionality of the student as a musician and unforeseeable results it might have on a musician's career, surgical treatment has been disadvised.

Standard clinical computed tomography fails to precisely visualise presence, course and branching points of deep cerebral perforators

BACKGROUND

Standard computed tomography (CT) images have earned a well-established position in neuroimaging. Despite that, CT is somehow limited by its resolution, which does not enable to distinctively visualise structures smaller than 300 μm in diameter. Perforating arteries, most of which measure 100-400 μm in diameter, supply important subcortical structures (thalamus, basal ganglia, internal capsule). Consequently, pathologies affecting these vessels (e.g. lacunar strokes) can have a devastating clinical outcome. The aim of our study was to assess standard CT's ability to visualise perforators and compare it with microscopic and micro-CT pictures.

MATERIALS AND METHODS

We have obtained 6 brainstem and 17 basal ganglia specimens. We infused them with barium sulphate contrast medium administered into either vertebral or internal cerebral artery. After that, the specimens were fixed in formalin and subsequently a series of CT, micro-CT and microscopic examinations were performed.

RESULTS

The median number of visualised perforators in brainstem and basal ganglia specimens was 8 and 3, respectively for CT and 18 and 7 for micro-CT (p < 0.05). Standard CT failed to clearly visualise branching points and vessels smaller than 0.25-0.5 mm (1-2 voxels) in diameter. Parallel vessels, like lenticulostriate arteries could not be differentiated in standard CT due to their proximity being smaller that the resolution.

CONCLUSIONS

Basing on our results, we infer that CT is a poor modality for imaging of the perforators, presenting both quantitative and qualitative flaws in contrast with micro-CT.

Menisco-fibular ligament - an overview: cadaveric dissection, clinical and magnetic resonance imaging diagnosis, arthroscopic visualisation and treatment

BACKGROUND

Injury to the menisco-fibular ligament (MFiL) is not commonly recognised. The anatomy of the lateral meniscus is complex and structure-function relationships are only partly understood. The purpose of the present study was to evaluate the MFiL, an anatomic structure rarely discussed that stabilises the lateral meniscus at the level of the hiatus popliteus and may have a crucial role in pathology of lateral meniscus injury.

MATERIALS AND METHODS

The MFiL was dissected from its attachment at the lateral meniscus to its insertion on fibular head in 12 human normal cadaver knees. The dimensions were determined and its anatomic position visualised throughout a 90° range of motion. Findings were documented on digital photographs and on video. Results were compared against the magnetic resonance imaging (MRI) appearance of the injured MFiL in 20 patients. Concomitant knee injuries in those patients were also analysed to determine the most frequent pattern of injuries.

RESULTS

The normal MFiL showed an inverted trapezoid-shape with a mean width proximally of 13 mm, mean width distally of 8.5 mm and a mean length of 18.4 mm. MRI visualisation of the ligament was possible even in regular sequences; however, additional radial plane sequences were also used. Arthroscopic visualisation and manipulation was optimal when the camera was inserted into the postero-lateral gutter with full knee extension.

CONCLUSIONS

The MFiL stabilises the postero-lateral knee in concert with the menisco-femoral ligaments. Injury to the MFiL can be a cause of chronic postero-lateral pain syndrome with associated instability. Further anatomical and biomechanical studies are needed in order to fully evaluate its importance.

Morphology of sesamoid bones in keyboard musicians

BACKGROUND

The sesamoid bones are small, usually oval bone structures often found in joints and under the tendons. Although their precise function is not fully understood, it is agreed upon that they protect the joints and make movements faster and less energy consuming. Sesamoid bones are found in hands, especially around first, second and fifth metacarpophalangeal joint and the interphalangeal joint of the thumb.

MATERIALS AND METHODS

This study compares a group of 32 young musicians to 30 non-musicians of similar age and posture. The hands of the subjects were examined by ultrasound imaging for the presence of sesamoid bones. The results were noted and observed sesamoids were measured.

RESULTS

The results seem to prove that although there are no difference in the amount or the location of the sesamoid bones between the musicians and the non-musicians, there is statistically significant tendency for the musicians to have bigger sum of the sesamoid's volume per hand (Fisher's test p-value = 0.034 < 0.05).

CONCLUSIONS

There was also observed an unusually shaped "Bactrian" sesamoid bone at the interphalangeal joint of the thumb in 8 cases in the musicians' group and 1 case in the control group. All participants with the aforementioned structure were female.

Course variability of the atlantic (V3) segment of vertebral artery: anatomical study with clinical implications

BACKGROUND

The atlantic segment of vertebral artery (V3) located at the centre of the cranio-vertebral junction is known for its variability and asymmetry, and is either the target or on the way of numerous procedures in this region. The aim of the study was to visualise variability of V3 segment.

MATERIALS AND METHODS

The V3 segment was studied in 49 specimens of the suboccipital region injected with coloured gelatine. Direct measurements were performed and probabilistic maps were created using digital photography.

RESULTS

The V3 segment has wavy course with possible lateral and significant postero-inferior expansions. In relation to the foramen transversarium the V3 reached up to 5 mm laterally, 23 mm posteriorly, 27 mm medially and up to 11 mm downward. Looking from the medial aspect the course of the V3 is less predictable compared to the lateral approach. Linear measurements and probabilistic maps revealed significant variability and large range of variation. There were 11 cases of V3 tortuosity found in studied material.

CONCLUSIONS

The complex and variable spatial conformation of V3 makes individual diagnostic and preoperative approach necessary.

Diversity of coronary arterial tree in laboratory mice

BACKGROUND

Research on the development and topography of mouse coronary arteries has been conducted for many years. Patterns of the course of these vessels have been described in various mouse strains. Our research focused on hearts of MIZZ mice.

MATERIALS AND METHODS

We visualised the coronary artery system by means of latex dye perfusion via the aorta. The injected latex did not reach the capillary vessel system.

RESULTS

The heart of MIZZ mice is supplied with blood by two main coronary arteries: the right and the left one. They deliver blood to the right and left part of the heart, respectively. The right coronary artery arises from the right sinus of the aorta and the left coronary artery from the left sinus. The interventricular septum is usually supplied by the septal artery, which is the main branch of the right coronary artery. All arteries of the coronary system run intramurally. The number of branches and the location of their ostia differed among the examined individuals.

CONCLUSIONS

Detailed information about the normal topography of coronary arteries, the number and course of their branches, as well as the area of the heart which is vascularised by these vessels constitutes the basic knowledge necessary to conduct further experiments.

Morphology and morphometry of the semitendinosus distal tendon in adults and foetuses

BACKGROUND

The distal tendon of the semitendinosus is often used as a graft in orthopedic reconstructive surgery. Knowledge of the exact morphology of this tendon, and also the ability to predict its morphometric data are certainly helpful when planning the procedure of surgery. Comparison of the semitendinosus distal tendon anatomy in adults and foetuses may be scientifically relevant. There are no scientific reports on this tendon anatomy in foetuses.

MATERIALS AND METHODS

Seventy semitendinosus muscles from cadavers were obtained using standard dissection techniques (50 muscles were obtained from adults and 20 from foetuses). Moreover, ultrasound examinations of 20 muscles were performed in living individuals.

RESULTS

Two main parts of the distal tendon were distinguished - the external part not covered with muscle fibres and the internal part, which is partially or entirely hidden within the muscle belly (venter). The average length of the distal tendon was 32.34 cm, while the average lengths of the external and internal parts were 9.65 cm and 12.59 cm, respectively. The external part was solid and cylindrical. The internal part was flat and rolled like a trough, thus making the tendon a poor transplant material. Similarly, the distal tendon in foetuses consisted of two parts, including the external and internal part.

CONCLUSIONS

The proportions between the lengths of different muscle parts were very similar in adults and foetuses.

The sonographic morphology of musculus palmaris longus in humans

BACKGROUND

The aim of this work was to describe morphology and morphometry of musculus palmaris longus and compare the outcome of Shaeffer's test with ultrasound imaging.

MATERIALS AND METHODS

Forty forearms of 20 healthy volunteers (11 females, 9 males) were tested by Shaeffer's test and ultrasound imaging. Anthropological measurements of the forearm and ultrasound guided measurements of musculus palmaris longus were taken. The outcome was tested for statistical significance by Fisher's test.

RESULTS

The examination revealed agenesis of palmaris longus in 6 cases, as well as 6 muscles showing quality variations. The Shaeffer's test gave 4 false-negative results. 28 muscles were described as spindle-shaped and 8 as pennated or bipennated. However, all the spindle-shaped muscles demonstrated a tendon going inside of the muscle's belly ranging from 2 cm to 11.5 cm. The relation between the circumference of the forearm right below the elbow (mean: 15.38 cm, SD: 1.83 cm) and the approximated volume of the palmaris longus muscle's belly (mean: 4.72 cm3, SD: 1.57 cm3) proved to be statistically significant (Fisher's test p-value < 0.05).

CONCLUSIONS

Uncommon morphological variations have been shown. Spindle-shaped muscles have proved to have their tendons continued inside them. Palmaris longus muscle's belly has proved to take significant amount of volume within the proximal forearm. Shaeffer's test has shown to have 10% false-negative ratio.

Stroke Bricks - spatial brain regions to assess ischaemic stroke localisation

Computer-aided analysis of non-contrast computed tomography (NCCT) images for rapid diagnosis of ischaemic stroke is based on the augmented visualisation of evolving ischaemic lesions. Computerised support of NCCT often leads to overinterpretation of ischaemic areas, thus it is of great interest to provide neurologically verified regions in order to improve accuracy of subsequent radiological assessment. We propose Stroke Bricks (StBr) as an arbitrary spatial division of brain tissue into the regions associated with specific clinical symptoms of ischaemic stroke. Neurological stroke deficit is formally translated into respective areas of possible ischaemic lesions. StBr were designed according to formalised mapping of neurological symptoms and were attributed to the uniquely defined areas of impaired blood supply. StBr concept may be useful for an integrated radiological CT-based assessment of suspected stroke cases or can be included into computer-aided tools to optimise the evaluation of stroke site and its extent. These data in turn are appropriable for further diagnosis, predicting the therapeutic outcome as well as for patients' qualification for an appropriate form of reperfusion therapy. The usefulness of StBr was illustrated in the case studies.

Human skull translucency: post mortem studies

Measurements of optical translucency of human skulls were carried out. An incandescent light source and a CCD camera were used to measure the distribution of light transmitted through the skull in 10 subjects post-mortem. We noticed that intra-individual differences in optical translucency may be up to 100 times but inter-individual translucency differences across the skull reach 10⁵ times. Based on the measurement results, a "theoretical" experiment was simulated. Monte-Carlo calculations were used in order to evaluate the influence of the differences in optical translucency of the skull on results of NIRS measurements. In these calculations a functional stimulation was done, in which the oxyhemoglobin and deoxyhemoglobin concentrations in the brain cortex change by 5μM and -5μM respectively. The maximal discrepancies between assumed hemoglobin concentration changes and hemoglobin concentration changes estimated with Monte-Carlo simulation may reach 50% depending of the translucency of the skull.

The anatomy of the anterior cruciate ligament and its relevance to the technique of reconstruction

Anterior cruciate ligament (ACL) reconstruction is commonly performed and has been for many years. Despite this, the technical details related to ACL anatomy, such as tunnel placement, are still a topic for debate. In this paper, we introduce the flat ribbon concept of the anatomy of the ACL, and its relevance to clinical practice.

Cite this article: Bone Joint J 2016;98-B:1020–6.

Uncommon branching pattern of the hepatic arteries in a living donor: a case report and brief literature review

Numerous variations of the hepatic arteries are common in surgical patients. We present a 35-year-old woman who was admitted to our department in order to assess possibility of becoming living donor. Preoperative computed tomography scan revealed anomalous branching pattern of the hepatic arteries. In this case right posterior sectoral artery has been given off by the greater pancreatic artery, left hepatic artery has been replaced by the artery arising from the left gastric artery and double segment 4 branches have been observed. To the best of our knowledge, this pattern has not been described in the literature, yet.

Arteries of the anterior wall of the maxilla in sinus lift surgery

Knowledge of the anatomical course of the anterior maxillary wall and alveolar process arteries is essential for sinus lift procedures. The aim of this study was to analyse the localization of anastomoses between the infraorbital and posterior superior alveolar artery on 101 computed tomography (CT) scans of maxillary sinuses (patients aged 18-70 years). The distance from the anastomosis to the bone point was measured on CT scans for each tooth location; for edentulous patients measurements were made to the lower edge of the alveolar process, and for dentate patients to the neck of the tooth. Measurements were done independently by two observers. The anastomosis analysed was identified on 50% of CT scans. The distance to the anastomosis was longest above the premolar (20.4 mm from tooth cervical line) and shortest above the first molar (15.9 mm to the edge of the alveolar process). The anastomosis can be localized on a CT scan for exact positioning of the antrotomy in 50% of patients. For the remaining patients, the anatomical information provided in this study can be used to reduce the risk of damage to the anastomosis. This study provides information on the distance from the anastomosis to the neck of preserved teeth in partially edentulous patients, which can be used as a reference point during sinus lift procedures.

Can palmar creases serve as landmarks for the deeper neuro-vascular structures?

PURPOSE

The aim of this study was the examination of the superficial anatomy of palmar creases and their relation to deeper neuro-vascular structures.

METHODS

Four creases: distal wrist flexion crease, thenar crease, proximal palmar crease and distal palmar crease were evaluated with reference to the following structures: palmar cutaneous branch of median nerve, palmar cutaneous branch of ulnar nerve, the nerve of Henle, transverse palmar branches from ulnar nerve, recurrent motor branch of median nerve, radial proper palmar digital nerve to the index and the ulnar proper palmar digital nerve to the thumb, Berrettini's communicating branch, ulnar nerve and artery, superficial palmar arch. We performed dissections of 20 cadaveric upper limbs derived from a homogenous Caucasian group. In our study we measured the location of surgically important structures with reference to palmar skin creases.

RESULTS

Among the other observations we noticed that the palmar cutaneous branches of the median and ulnar nerves were located at least 0.5 cm away from the thenar crease. The superficial palmar arch was found between the thenar and proximal palmar crease and never crossed the proximal or distal palmar creases.

CONCLUSIONS

These anatomical dissections will provide reference material for further ultrasound studies on the arrangements of neuro-vascular structures in reference to superficial palmar creases.

Clinical anatomy of the auriculotemporal nerve in the area of the infratemporal fossa

The auriculotemporal nerve is a sensory branch extending from the posterior section of the mandibular nerve trunk. Its nerve roots form a short trunk, which gives off a number of branches, innervating: the temporomandibular joint, the temporal region, structures of the external ear: auricle, and external acoustic meatus, and the parotid gland. It also conducts excretory fibres to the buccal and labial glands. Anatomical relationships between the auriculotemporal nerve and the muscles of mastication, temporomandibular joint, and surrounding vessels in the area of the infratemporal fossa create favourable conditions for entrapment syndromes. Entrapment of the auriculotemporal nerve plays a role in the pathogenesis of temporomandibular joint pain syndromes, headaches, as well as pain symptoms or paraesthesias within the external acoustic meatus and auricle. The current study was performed on 16 specimens containing the infratemporal fossa. Some variations in the nerve roots of the auriculotemporal nerve were found and described as one-, two-, three-, four-, and five-root variants. The topography of the auriculotemporal nerve and its close relationship to the structures of the temporomandibular joint were described. Individually, the variable topography of the nerve course may play a role in the symptomatology of headaches and localisation of pain in the face regions and masticatory system.

Anatomy of the medial femoral circumflex artery with respect to the vascularity of the femoral head

We performed a series of 16 anatomical dissections on Caucasian cadaver material to determine the surgical anatomy of the medial femoral circumflex artery (MFCA) and its anastomoses. These confirmed that the femoral head receives its blood supply primarily from the MFCA via a group of posterior superior nutrient arteries and the posterior inferior nutrient artery. In terms of anastomoses that may also contribute to the blood supply, the anastomosis with the inferior gluteal artery, via the piriformis branch, is the most important. These dissections provide a base of knowledge for further radiological studies on the vascularity of the normal femoral head and its vascularity after dislocation of the hip.

Median aperture of the fourth ventricle revisited

BACKGROUND

The median aperture of Magendie is the largest of three openings of the fourth ventricle and thus it forms the main path for the outflow of the cerebrospinal fluid from the ventricle. The Magendie aperture connects the fourth ventricle with the cisterna magna and makes a natural corridor for neurosurgical approach and inspection of the ventricle and its floor. The purpose of this study was to give a contemporary anatomical view of this structure in the context of historical data.

MATERIAL AND METHODS

The Magendie foramen was studied in 30 fixed specimens of human brainstems with cerebella. The microdissection technique was used. Measurements were taken with a microscope ocular ruler.

RESULTS

The aperture is limited by the following structures: obex and gracile tubercles inferiorly, and tela choroidea with choroid plexus superolaterally. Obex tubercles usually have the form of a piece of neural tissue bridging two halves of the brainstem above the entrance to the central canal. Gracile tubercles together are 8.15 mm wide and the maximal width of the foramen is 6.53 mm. Tela choroidea attaches laterally at both sides to the inferior medullary velum. In most cases the right and left choroid plexus are connected to each other with a triangular membrane of tela choroidea, which protrudes through the median foramen and attaches to the vermis at a highly variable level.

CONCLUSIONS

We hope that the presented description of anatomical relations around the Magendie aperture, with its new measurements, will be helpful for those operating in the area and will explain some of the inaccuracies found in literature.

Radiological anatomy of the ambient cistern in children

Ambient cistern (AC) is a thin extension of the subarachnoid space surrounding the brainstem at the level of the mesencephalon and pons. Despite various definitions, it constitutes an important landmark in clinical assessment of intracranial volume reserve. Although it is indisputably useful, there exists no defined standard for radiological examination for the dimensions and ranges in specific age groups. This paper aims to describe the ambient cistern anatomically and give the ranges of dimensions for proper radiological interpretation. The study was performed on 160 axial computed tomography (CT) examinations of Polish children of both sexes, aged 1-18 years, admitted to the hospital because of mild brain concussion. Pictures were made using a Siemens 8-row CT scanner, without contrast administration. We estimated distances at the level of the pons and midbrain, based on axial cross-sections, according to standard radiological protocol. The parameters included the width of the AC in its anterior and posterior part, the width of the tentorial notch, and the distance from the pons and sella. All measurements were analyzed statistically with StatSoft Statistica 8.0 software. The average width of the AC differs between age groups. It is greatest at 1-3 years (2.8 +/- 0.6 mm) and lowest at 4-10 years (2.4 +/- 0.6 mm). AC is more likely to be greater in its anterior part in boys. The distance from the sella to the pons is greatest in 1-3-year-old girls (6.9 +/- 1.3 mm), and the tentorial notch is widest in the 15-18-year-old group (24.6 +/- 2.4 mm). Dimensions of the AC correlate with intracranial reserve volume. This is particularly visible in the youngest children. Thin and narrow AC is not always a sign of raised intracranial pressure. It may be specific for the child's age.

Image-guided dissection of human white matter tracts as a new method of modern neuroanatomical training

Neuronavigation is a kind of image-guided surgery used during neurosurgical procedures. Based on specific equipment which is compatible with the software calculating and processing the patient's data; this method allows the determination of the location of anatomical structures and visualisation of surgical instruments in the operative field. Although standard brain dissection is still the best method of neuroanatomical training, some limitations occur. The most important of these is the inability of conversion from three-dimensional (3D) view to flat pictures of the brain structures, as viewed on computed tomography (CT) and magnetic resonance imaging (MRI), being essential in neuroanatomical training nowadays. The aim of the study was the implementation of a neuronavigating system for brain anatomy training purposes. The study was performed on 10 human brain hemispheres, dissected due to classical methods (standard brain anatomical sections, stepwise ventricular system opening and partial dissection of white matter tracts using Klingler's dissection technique). The material was scanned in a 1.5 T magnetic resonance scanner using a modified neuronavigation protocol. The brains were prepared before dissection as proposed by Klingler. The subsequent steps of the dissection were documented with a digital camera. The progress of the dissection was visualised using the neuronavigation system (Medtronic Stealth Station Treon) with cranial application software. In the course of the study, numerous 3D and 2D images were obtained. The images were related to each other and linked anatomical structures in the specimen with their appearance on CT and MRI scans. The implementation of a neuronavigation system for brain structures dissection facilitates visualization and understanding of their proper location. This new method offers a constant and precise orientation and simplifies understanding of the relation of the 3D view of a specimen to that of the 2D image.

The study of arterial anastomoses in the region of the alveolar process and the anterior maxilla wall in foetuses

The anterior maxilla wall and alveolar process are covered by the arterial network. Procedures in this region can cause heavy bleeding. Knowledge of the anatomical course of a particular artery is essential for performing surgery in this area. The aim of this study was to search for and then analyse anastomoses between the infraorbital and posterior superior alveolar artery. In the study, 19 maxillas of foetuses were analysed. The arteries were injected with coloured latex. The dissection was carried out using a surgical microscope and microsurgical equipment. The lower eyelid with cheek skin was separated and the facial muscles were cut to expose the maxilla and arteries of the alveolar process. The study revealed that in 10 out of 19 of the specimens there was an arterial connection between the infraorbital and posterior superior alveolar artery. The course of the analysed anastomosis was diverse. In all cases we observed an anterior superior alveolar artery. In all specimens the alveolar process was vascularised by many arteries originating from the analysed anastomosis. The location of the analysed anastomosis can be stated before operation, on the line between the medial eye angle and the sixth tooth of the same side. The anastomosis described in the study means that caudally running arteries are important in choosing incisions in procedures performed at the alveolar process.

Anatomy of the posterior cruciate ligament

The purpose of the study was to explain the architecture of the posterior cruciate ligament because the views on its structure presented in the literature are inconsistent - from those considering it as indivisible to those presenting it as a multifascicular structure. Twenty formalin-fixed ligaments from human knee joints were tested using the preparation technique. All posterior cruciate ligaments clearly divided into the anterolateral bundle and the posteromedial bundle (20/20). In all ligaments, 2 fascicles were identified in the posteromedial bundle (20/20). In most cases, 2 fascicles were also seen in the anterolateral bundle (14/20). Less commonly, it consisted of multiple fascicles (6/20).

The anatomy of the fundic branches of the stomach: preliminary results

The fundic branches of the stomach can be defined as a group of vessels that can arise either directly or indirectly from the following source arteries: the left inferior phrenic artery, the accessory left hepatic artery, the left gastric artery, the left middle suprarenal artery, the main trunk of the splenic artery, the posterior gastric artery, the superior polar artery, the gastrosplenic artery, the left gastroepiploic artery and the splenic artery with its inferior and superior terminal branches. It is worth mentioning that the fundic branches of the left gastroepiploic artery and the superior and inferior terminal branches of the splenic artery, like other vessels arising from these three source arteries and supplying the stomach, are defined as short gastric arteries. The anatomy of these fundic branches, particularly relevant to some surgical procedures, is not sufficiently described, and the current literature suffers from lack of publications on this particular topic. We therefore decided to explore in detail the arterial vascularisation of the gastric fundus. The research was carried out on material consisting of 15 human stomach specimens. The anatomical analysis comprised the following: the number of occurrences of fundic branches in each of the source arteries defined above, the distance between the origins of the source artery and its arising fundic branch, the way in which the fundic branches arose, the length, diameter at point of origin and morphology of the fundic branches, as well as the exact point of perforation of each fundic branch on the fundus. The highest incidence of the direct-branching pattern of fundic branches was in the left middle suprarenal artery, the gastrosplenic artery and the left gastrosplenic artery. The accessory left hepatic artery, the left gastric artery and the main trunk of the splenic artery were the most frequent site of the indirectly arising pattern of fundic branch. The highest median value of fundic branch length was 63.05 mm, found in the accessory left hepatic artery group. The largest median diameter value of the vessel was encountered among those originating in the left middle suprarenal artery and reached 2.17 mm. The posterolateral quadrant of the fundus received the largest number of fundic branches, amounting to 46.5% of all the fundic branches studied.

Anatomy of branches of the musculocutaneous nerve to the biceps and brachialis in human fetuses

Forty upper limbs (20 right and 20 left) of spontaneously aborted human fetuses were examined to determine the branching patterns of the musculocutaneous nerve. The mean age of the fetuses was 21.3 weeks. We identified three branching patterns of the musculocutaneous nerve to the biceps muscle. Type I with a single primary branch occurred in 47.5% of cases. Type II with two primary branches each to a separate head of the biceps muscle was observed in 42.5% of cases. Type III consisted of two primary branches, the proximal dividing into two branches, each to a different head of the biceps, and the distal branch supplying the common belly. Type III was present in 10% of cases. We found only one branching pattern for the brachialis muscle, a single primary branch. In our material communicating branches between the median and musculocutaneous nerves were found in 20% of specimens. We measured the distances between the acromion and the exit points of the first and second branch to the biceps, which averaged 36.3% for the first branch regardless of the type of branching pattern, 54.2% for the second branch in Type II, 60.7% for the second branch in Type III and 60.9% for the branch to brachialis, expressed as a percentage of the distance between the acromion and the lateral epicondyle.

Endoscopic study of the morphology of Vieussens valve

Vieussens valve (Vv) is the ostial valve of the great cardiac vein located near the beginning of the coronary sinus. Knowledge of its anatomy is important for several trans-sinus cardiologic procedures. The frequency of its presence is reported to vary from 65-87%. We documented the post mortem morphology of Vieussens valve in 50 unfixed, intact human coronary sinuses using endoscopy. We believe this is the first study of the anatomy of the coronary sinus and the adjacent venous ostia to employ this technique. Vieussens valve was observed in 78% of specimens. Special attention was given to the shape of the valve leaflets. Five morphological types of Vv were distinguished: single leaflet, flat (16%); single leaflet, concave (20%); double leaflet, flat (8%); double leaflet, concave (32%); and triple leaflet, concave (2%). We found post mortem endoscopy of the coronary sinus to be a good and reliable method of visualizing Vieussens valve.

Some remarks concerning basic anatomy of joints

Many clinical disciplines demand revision of anatomical description. Classic anatomical description does not always fit to physiologic and functional observations. However, most of the anatomical nomina are clear and enough to be valid for all medical disciplines. Authors present some remarks concerning basic anatomical knowledge of diarthrodial joints.

The anatomy of the median branches of the basilar artery

The aim of study was the examination of the median branches (MB) of the basilar artery (BA). 783 MB were found in 100 human brainstems injected with coloured latex. The attachment of the MB to the quadrants of the BA's trunk, their structural shape, length of trunks, topographical arrangement (on three vascular levels) and the clinical importance of this vascular pattern was evaluated. The MB arise from Pr and Pl quadrants of the BA's trunk in 100% cases, represent 37.7% of BA's branches and are mostly located in the foramen caecum area (56%). The MB confine the BA's stem mobility on the V CN area and above, because of their shortest trunks especially on these vascular levels. In the examined specimens the MB varied in number from 0 to 22 (mean, 8).

Anatomical determinations of surgical approaches to the hip joint and their modifications for revision hip arthroplasty

Authors present basic anatomical review of surgical approaches to the hip joint and some considerations of modifications of standard approaches during revision hip arthroplasty.

Lexicon of synovial bursae

A synovial bursa (bursa synovialis) is a recess in the articular cavity, formed at a point where the fibrous layer of the articular capsule has become thin and the synovia is able to extrude beyond it. Many bursae lose their connection with the articular cavity they accompany. Their function is to enhance the sliding of muscles, tendons, and other soft tissues in relation to movable bone structures, and to shift loads between bones and soft tissues. The anatomy of bursae is of importance in the endoscopic surgery of joints and of the bursae themselves. In many clinical situations the dominant symptoms may originate from particular synovial bursae. The Terminologia Anatomica (1998) lists ca. 50 bursae. The authors review the current state of knowledge regarding the anatomy of synovial bursae. Those of particular clinical importance are identified and suggestions are made for reconciling differences in clinical and anatomical terminology.

Nutrient foramina in the diaphyses of long bones

This paper presents the localization and number of nutrient foramina in human long bones. Based on the literature and their own observations, the authors describe the sites and courses of nutrient vessels in the humerus, radius, ulna, femur, tibia, fibula and other long bones.

[Modelling cerebrovascular circulation from the viewpoint of autoregulation mechanisms]

The rationale for cerebral blood flow modelling is to extrapolate the possible effects of the pharmacological agents and significance of different pathologic states. Most authors present linear, statistical models. Such modelling does not take into consideration many important factors. Autoregulation of cerebral circulation is the most important one. It maintains cerebral blood flow on a constant level despite significant changes of systemic pressure. Influence of autoregulation is necessary for evaluation of the different anatomical configurations of the main supplying arteries and the cerebral arterial circle of Willis. This paper presents original, non-linear and dynamic model of the cerebral circulation with factor of autoregulation. Comparison of the data from the modelling and from the clinical observations shows high correlation.

The anatomy of surgical approaches to the cervical spine

The authors present the anatomical basis of surgical approaches to the cervical spine. The posterior, anterior, and transpharyngeal approaches are described, with particular attention to orientation structures, incisions, surgical dissection, and anatomical considerations regarding various hazards encountered during surgery of the cervical spine.

Middle superficial cerebral vein

The microanatomical study present the anatomy of the middle cerebral vein. On the basis of the anatomical data we distinguished concentric and nonconcentric types of tributaries of the middle superficial cerebral vein. The nonconcentric type prevails.

[Contribution to the microanatomy of the proximal part of the arteria centralis longa (Heubner's artery)]

The anterior communicating artery complex is one of the most frequent intracranial aneurysm sites. Pterional craniotomy is the usual way to expose this region. While exposing of the aneurysmal dome, the posterior part of the gyrus rectus is frequently resected. In this stage of the procedure and later during clipping of the aneurysm, the surgeon's manipulation is closely related to the proximal part of the Heubner's artery. This vessel feeds important structures in the region of the basal ganglia. The anatomy of the Heubner's artery was described by many authors. However the intraoperative identification of this artery is still not clear. Therefore we performed detailed microanatomical investigation of the proximal part of the Heubner's artery in 40 brain hemispheres. It was found that during resection of the posterior part of the gyrus rectus two arteries are exposed. The recurrent Heubner's artery runs posteriorly to the gyrus rectus. The second artery runs on the medial and inferior surface of gyrus rectus supplying cerebral cortex. This artery frequently originates from the A1/A2 junction or the proximal part of the A2 segment of the anterior cerebral artery. Because of it, this cortical artery is difficult to distinguish from the recurrent Heubner's artery. This artery can branch out from the recurrent Heubner's artery or the frontopolar artery. In conclusion, the greatest probability of the injury to the recurrent Heubner's artery may occur during resection of the posterior part of the gyrus rectus.