anatomical study of the ligamentum flavum

The functional importance of the ligamentum flavum to the integrity of the vertebral column and the frequency with which they are encountered surgically justify consideration of its anatomy in adults. The aim of this study was to make a detailed investigation of the gross and microscopic anatomy of the ligamentum flavum. The information reported in this study is of clinical value in the practice of lumbar epidural anaesthesia. The material used were 14 normal male cadaveric lumbar vertebral columns in the middle and old age. Length, width and thickness of the ligamentum flavum were measured in the lumbar region in millimeters. Computed tomography was done on 30 patients [18 males and 12 female] complaining of problems far away from the lumbar region that was studied. Width and thickness of the ligamentum flavum were measured by CT. Various portions of the 14 gross specimens were chosen for microscopic study. Sections were prepared and stained by Masson trichrome and Orcein and examined by light microscopy. The ligamentum flavum was found to be attached inferiorly to the superior edge and the posterosuperior surface of the lamina below. Some deep fibres were attached to the antero superior surface of the lamina below. Thus the ligamentum flavum was considered to be formed of superficial and deep parts. The ligamentum flavum was attached superiorly to the inferior edge and the anteroinferior surface of the lamina above. The medial border of the ligamentum flavum corresponded to the base of the spinous process. The lateral border extended as far as the intervertebral foramen. The direct-ion of fibres of the superficial part of the ligament was upwards and medially towards the spine and was more oblique in its lateral portion close to the intervertebral foramen. The direction of the deep fibres was craniocaudal. The length, width and thickness of the ligamentum flavum of the normal male cadavers had a mean of 16.4 +/- 5.2mm, 18.7 +/- 3.4mm and 4.5 +/- 0.8mm respectively. By CT of thirty patients, the width and thickness had a mean of 16.7 +/- 2.6mm and 43 +/- 0.6mm respectively. Histological results showed that the ligamentum flavum was chiefly made up of elastic connective tissue which in older age specimens decreased due to its fragmentation with increase in the amount of the collagenous tissue. The information reported in this study is of clinical value in the practice of lumbar epidural anaesthesia. It is suggested that the epidural puncture can be best performed through the lower and medial portion of the ligamentum flavum [slightly lateral to the midline] to be away from the intervertebral foramen

vascularization of symphysis pubis in the albino RAT

Little attention has been paid to study the vascular nutritional pathways to the symphysis pubis. Knowledge regarding the nutrient sources and degree of vascularisation of the fibrocartilaginous structures especially the articular discs of symphysis pubis in virgins and during late period of pregnancy is fundamental for physiotherapists and physicians for clinical decision making. This work was undertaken to describe the vascular nutritional pathway to the symphysis pubis in rats using light microscopy and immunohistochemistry and to describe the structural transformation observed in the symphysis pubis during the intrapartum period. 20 rats [8 males and 12 females] 80 - 100 days of age were used in this study. The symphysis pubis was excised and specimens were prepared for light microscopy and immunohistochemistry. The interpubic disc has two distinct portions: an inner bearing portion made up of cartilage and a peripheral portion made up of dense connective tissue. Blood vessels that supply the medial extremity of each pubic bone, penetrate the muscle attachments and the articular tissue to supply the pubic ligaments and the fibrous rim of the interpubic disc. The subchondral bone also share in giving blood supply to the symphysis pubis as it shows several marrow contacts linking the marrow space of the pubic bones with the interpubic disc. Histological examination revealed more intense factor VIII staining in the joint in intrapartum specimens indicating more angiogenesis. The lengthening of the articular gap is seen in intrapartum specimens. The symphyseal gap changes morphologically in intrapartum specimens as a result of pregnancy. Its width increased and it assumed the structure of a ligament. Mononuclear cellular infiltration was demonstrated in the interpubic tissue around parturition. As a result of delivery, traumatic changes occur leading to progressive loosening of the symphysis pubis and production of cartilaginous nodules. Changes in the symphysis pubis noticed as an effect of pregnancy are increased vascularity, increased deposition of collagen, mononuclear cellular infiltration and formation of cartilaginous nodules. These results are of interest to physiotherapists and physicians. Knowledge regarding the degree of vascularisation of the symphysis pubis in virgins and during late period of pregnancy is fundamental for clinical decision making. A clear understanding of the changes that occur in the symphysis pubis at term would be of great benefit to the diagnosis and management of any pathophysiological condition that may happen at parturition

histological study of the dura mater using light and electron microscope

The present study has been undertaken to investigate the ultrastructure of the dura mater so as to correlate its structure with its mechanical function. This study aimed also to contribute further to the understanding of the functional morphology of the barrier formed by the mesothelial lining of the arachnoid mater to find a satisfactory explanation of the mechanism of bulk outflow of cerebrospinal fluid from the subarachnoid space into the dural sinuses. The clinical implication of this study in lumbar puncture procedure is also discussed. Six young adult sheep, eight rats, and four monkeys were used in this study. Specimens of 7 human lumbar dura and arachnoid were obtained during surgical treatment of disc herniation. Dura and arachnoid specimens were prepared for light and electron microscopy. Human Lumbar dura mater is divided into three parts: outer, middle and inner. In the outer part of the dura, collagen appears to be running in a longitudimal direction. Few elastic fibers and nerve fibers are also present. In the middle part, the collagen fibers are arranged in various directions with few elastic fibers in between. The inner part is less dense with collagen running mainly in a longitudinal direction. Numerous fibroblasts are present. The outer arachnoid is lined by a single layer of mesothelial cells. Below this are dark cells. The inner spinal human arachnoid is composed of groups of clear cells As regards spinal dura and arachnoid in the sheep, collagen fibers appear, in the outer dura, to be running in a longitudinal direction. In the middle dura, collagen is arranged in various directions. The inner dura is composed of collagen fibers running longitudinally and obliquely. Dark and light cells are present in the arachnoid. The collagen in the rat's dura is running mainly in a longitudinal direction in the outer part of the dura and in various directions in the inner part. The dural-arachnoid interface is readily identified by the presence of electron-dense granular material. At places, the arachnoid cells approximate that dense band thus diminishing the subdural space. The arachnoid is composed of fibrous connective tissue with numerous trabeculae. The arachnoid dark cells are characterized by dark nuclei with abundant heterochromatin. The dura of the monkey is composed of dense fibrous connective tissue consisting of collagen bundles and fibroblasts. The inner dura is highly cellular containing elongated fibroblasts. The collagen is loosely arranged in the inner dura. The subdural space is observed at the dural arachnoid interface in places however, this space was obliterated by the close approximation of the dural and arachnoid walls. The arachnoid is composed of two types of cells, clear and dark. The dura is composed of dense flbroblastic connective tissue and the collagen fibers are its major structural component. They have the strongest mechanical properties. Thus, the orientation of collagen fibers may explain the mechanical properties observed in different tissues. It has been previously indicated that the collagen fibers are arranged in a longitudinal and this explains the strong mechanical properties of the dura when subjected to stretching and deforming forces during movements and postural changes. Hopefully, increased understanding may open the way for new approaches in the evaluation of dural lesions produced by different needle bevels and the relationship of dural lesions to the production of postural headache

ultrastructural study of the atrioventricular valves in the mice

Mice atrioventricular valves exhibit a number of morphological similarities to their human homologues. This research aimed to undertake a thorough study of the atrioventricular valves of mice. The success of treatment of the atrioventricular valve diseases is dependent on a thorough knowledge of its anatomy. In the present study, 20 mice of both sexes were used. The thoracic walls of the animals were opened, and the hearts were extracted and washed thoroughly with phosphate buffered saline. The annulus, leaflet tissue, chordae tendineae, and papillary muscles of the tricuspid and mitral valves were carefully dissected. The dissected specimens were processed for light and transmission electron microscopic examinations. The fine structure proved to be the same in both atrioventricular valves. The leaflets of the two AV valves were formed of a fibrous layer in its lower third [on the ventricular side] and a spongy layer in its middle third [on the atrial side] where the muscle cells were progressively lost. The fibrosa consisted of collagenous bundles that were differently oriented in right and left AV valves. The spongiosa was formed by a loose network of thin collagen fibers, fibroblasts and scattered elastic fibers. The chordae tendineae were structurally similar in the two AV valves where they were formed of three distinct layers: an outer layer of simple flattened endocardial cells, a basal lamina of loose collagen and few elastic fibres, and a central core of collagen with few scattered fibroblasts. The papillary muscles of the left ventricle extended from the heart apex toward the annulus fibrosus. In one third of specimens, the anterior papillary muscle has a free base that was always attached to the ventricular wall by thin chordae tendineae. The present study has demonstrated the microanatomy of the AV valves in mice, hoping at enhancement of human clinico- pathologic correlation when their functions become abnormal

anatomical study of the lumbosacral ligament

The structure of the human lumbosacral region should be studied extensively in attempts to diagnose possible anatomical sources of low back pain. Only few studies have examined the correlation between the disposition of the ligaments at the level of the fifth lumbar intervertebral foramen and nerve root entrapment. This work was carried out to investigate the anatomical attachment, length and width of the lumbosacral ligament and to determine if the ligament could cause compression of the 5[th] lumbar nerve. In this study, fifteen cadavers [thirty specimens] were dissected and the position and relations of the lumbosacral ligament were examined bilaterally. The ligament was found to be present in all the specimens. It extends from the transverse process of the 5[th] lumbar vertebra to the ala of sacrum. The ligament was found to pass anterior to the 5[th] lumbar nerve in thirteen specimens out of thirty [43.3%]. This may cause compression of the nerve at that site. The measurements of the ligament were done with a digital sliding caliper. The 5[th] lumbar nerves passing deep to the ligament were examined histologically to see signs of compression of the nerve. The compressed nerves showed increased thickness of endoneurial perineurial and epineurial connective tissue. These results are of interest to the clinician whose patient presents with L5 root signs and with a myelogram or computed tomographic scan which do not show any abnormality. The possibility of extra-foraminal compression must be considered as a possible source of the clinical signs

Estimation of the femur length from the markers of its proximal end

Length of femur and stature are of forensic and anthropological significance. In major disasters when only a fragment of the proximal femur is available, some markers such as the head and neck of the femur can be of use in determining the femoral length. A radiographic study included a total of 130 unpaired Egyptian living femora devoid of gross pathology and grouped by side and sex into 66 males [30 right and 36 left] and 64 females [34 right and 30 left]. The femora of living persons were x-rayed keeping at a fixed distance and in a fixed position. These radiographs were used to measure the neck-shaft angle [NSA], neck length [NL], intertrochanteric apical axis length [ITAAL], maximum vertical diameter of the femur head [VDH] and maximum femur length [FL]. The data were statistically analysed for regression. Length of the femur significantly correlated with the NSA, NL, ITALL and VDH. Simple linear regression equations of the length of femur against the neck-shaft angle, neck length, intertrochanteric apical axis length and maximum vertical diameter of the head have been derived. The calculated length of the femur can be used to estimate the stature of the individual

Age estimation by skeletal maturation of the bones of the wrist and hand in the Egyptian boys and girls

The hand with its numerous secondary centers in phalanges and metacarpals and the wrist with its tightly packed primary centers are useful for the purpose of recording progress of skeletal maturation and in identification. This study aimed to establish both a chronological sequence of postnatal skeletal maturation in the Egyptian children and the intersexual differences. In this study, 156 radiographic plates of the hand and wrist in posteroanterior projection of the Egyptian children between 1-13 years of age. All cases were free from any pathological conditions that could alter the normal skeletal development. The ossification centers studied in each case, corresponded to the distal epiphysis of ulna and radius, the campus, the metacarpals and the phalanges. It was found that there was a significant differences in mean [Ba] between girls and boys at 9 and 11 years where girls showed significantly higher mean [Ba] than boys. The difference between [Ba] and [Ca] was a negative value in more males than females. A detailed and ordered study of ossification center of each bone of the hand and wrist was made and the intersexual differences were demonstrated. The [Ba] and [Ca] was related statistically and the results was represented graphically. A high statistical correlation between the two variables was found. Standards representing the length of metacarpal bones and phalanges were obtained. Girls have significantly longer second metacarpal bone than boys in all age groups except at 1 and 9 years of age. Males have significally higher mean total diameter of second metacarpal than females in all age groups from 1 to 10 years except at the age of 5 years