Anatomical variations of the arrangement of structures at the pulmonary hilum: a cadaveric study.

PURPOSE: The aim was to study the anatomical variations of the arrangement of structures at the hilum of the lung. METHODS: The present study examined the hila of 110 cadaveric lung specimens of south Indian population. The anatomical variations of the arrangement of structures at the hilum were macroscopically observed. RESULTS: It was observed that the variations were higher in the left lung than in the right lung. The variations were observed in 16.1 % of right lungs and 48.2 % of the left lungs. There were some interesting anatomical variations like the two upper pulmonary veins, two pulmonary artery, two bronchi in the hilum of the left lung, three bronchi, four pulmonary veins and four bronchi. The present study was compared with a similar study from the same geographical location. It was observed that the frequency of variations and the hilar morphology of the arrangement of structures differ among the two separate studies from south India. CONCLUSIONS: The observations of the present study suggest that the pulmonary hilar morphology is extremely variable.

Occipital emissary foramina in human skulls: an anatomical investigation with reference to surgical anatomy of emissary veins.

AIM: The objectives were to find the incidence and topography of the occipital emissary foramina in skulls of South Indian Region. MATERIAL AND METHODS: In the present study, 78 dried adult human skulls were examined. They were analyzed for the gross incidence and position of the occipital emissary foramen. The observations were made in the squamous part of the occipital bone from the posterior margin of the foramen magnum to the external occipital protuberance. RESULTS: From our observations, the occipital emissary foramen was present in 11 (14.1%) skulls. Left sided foramen was observed in 5 cases (6.4%), right-sided foramen in 4 (5.1%) and the median foramen was seen in 2 (2.6%) of the cases. CONCLUSION: The occipital emissary vein is present in a small percentage (14.1%) of cases. It was also demonstrated that its location is variable as to left, right or midline. Its location was closer to the foramen magnum than to the external occipital protuberance in all the specimens. The morphology of this subject is important to the neurosurgeons and plastic surgeons. The knowledge is of importance in suboccipital craniotomies as this foramen transmits the occipital emissary vein and will keep awareness among the surgeons to avoid the excessive bleeding.

Dual innervations of mylohyoid muscle: a case report.

Mylohyoid and anterior belly of the digastric muscles are supplied by a branch from the inferior alveolar nerve called the mylohyoid branch. Here we present an unusual finding in a 60-year-old male cadaver in which the mylohyoid muscle is supplied by a branch from hypoglossal nerve in addition to its usual nerve supply. Hypoglossal nerve after giving superior root of the ansa cervicalis and muscular branches to thyrohyoid and geniohyoid muscles gave another branch to supply the mylohyoid muscle. Any variation in the formation and/or branching pattern of ansa cervicalis or hypoglossal nerve can cause confusion and may complicate the procedures involving this nerve such as skull base surgery, neck dissection, and anterior cervical spinal approach. Developmentally mylohyoid muscle is from the mesoderm of the first arch, therefore, must be innervated by the mandibular nerve. Hence, we report this uncommon variation based on embryology and the clinical implications.

Four-headed biceps and triceps brachii muscles, with neurovascular variation.

Anatomical variations of the biceps brachii and triceps brachii have been described by various authors, but the occurrence of four-headed biceps brachii and triceps brachii in an ipsilateral arm is rare and has not been reported before in the literature. During routine cadaveric dissection in the department of anatomy, Kasturba Medical College, Mangalore, India, various unusual variants were noted in the left arm of a cadaver of a 67-year-old man. The variants include a four-headed biceps, a four-headed triceps, communication between the musculocutaneous and median nerves, and a high origin of deep brachial artery from the axillary artery. The occurrence of these anomalies and the clinical and morphological significance are discussed.

The morphology of meningo-orbital foramen in south Indian population.

When present, the meningo-orbital foramen forms an additional link between the orbit and the middle cranial fossa. It contains an arterial anastomose between the middle menigeal artery--the meningo-lacrimal branch and the lacrimal artery--the meningeal branch. The incidence of this foramen is known to vary between 28-82.9%. In the present study of 138 dry adult skulls of South Indian origin, the meningo-orbital foramen was present in 80.4% of population. The mean distance of the meningo-orbital foramen from the supra-orbital notch was 34.14 mm (29-38 mm) and from the fronto-zygomatic suture it was 26.10 mm (28-35 mm). The incidence and location of the meningo-orbital foramen may be of surgical significance to ophthalmologists (Tab. 1, Fig. 3, Ref. 7).

An accessory iliacus muscle: a case report.

We present a case of an anomalous accessory iliacus muscle in the iliac fossa which gets originated from the iliac crest and inserting along with iliopsoas, and appear to compress the L4 root of femoral nerve. During the routine dissection of a male cadaver aged 58 years, we found an accessory iliacus muscle. The L2 and L3 nerve roots joined the L4 root distal to the accessory iliacus muscle. The L4 root of the femoral nerve supplied accessory iliacus muscle. Accessory iliacus muscle might cause tension on the femoral nerve resulting in referred pain to the hip and knee joints and to the lumbar dermatome L4. The clinical significance of this variant muscle and its importance in the femoral nerve entrapment has been discussed.

Clinical significance of a mysterious clival canal.

During routine osteology demonstration of the posterior cranial fossa we noticed a transverse bony canal in the middle third of the clivus of an adult male skull. The canal was situated 1.8 cm in front the anterior border of the foramen magnum. The length of the canal was 0.6 cm long. The possible embryological basis and clinical significance of the variation was discussed.

Pancake kidney with a single ureter: a rare incidental observation at autopsy.

We report an extremely rare case of a pancake kidney with a single ureter. During the medicolegal autopsy on the body of a traffic accident victim, the kidneys were not located in the abdomen. The anterior surfaces of both kidneys were completely fused in the pelvic cavity, and the kidney was shaped like a pancake. This pancake kidney had accessory renal arteries around it and one renal vein from each kidney. The left renal vein was much smaller in diameter than the right one. There were two major calyces, one each from each kidney. The major calyces joined to form a single renal pelvis from both the kidneys, which continued as a single ureter. The renal pelvis and ureter lay posterior to the pancake kidney. Urologists and pelvic surgeons should be aware of the variant anatomy of the pancake kidney, particularly concerning its vasculature, to prevent unexpected catastrophic bleeding. If the kidneys are not located in the abdominal cavity, the autopsy surgeon must consider the possibility of its presence in the pelvic cavity. This could be especially important during medicolegal investigations into allegations of missing kidneys and unlawful kidney transplantations.

In vivo magnetic resonance imaging morphometry of the patella bone in South Indian population.

Racial differences exist in the dimensions of structures and the commercially available prostheses are designed based on the Caucasians. In this context, the goal of the present investigation was to determine the gender wise measurements of patella bone in South Indians. The present study included axial magnetic resonance images of the knee joint from 140 South Indian adults (70 males, 70 females; aged between 20-70 years). The angle, width, thickness, lateral facet width, facet thickness, ratio of the lateral facet, the relative thickness and ratio of facet thickness were measured in the patella by using the digital ruler. The statistical analysis was performed by using the SPSS software. The dimensions exhibited statistically highly significant sexual dimorphism (P≤0.001). The mean value was higher in males than females except for the ratio of patellar lateral facet and patellar facet thickness ratio. It was observed that the males exhibit more variability than females in all the measurements of patella except patellar thickness, patellar facet thickness, patellar relative thickness, and patellar facet thickness ratio. The present study of the in vivo morphometry of patella bone from the South Indians can provide a population and gender specific database for the morphometric measurements of the patella. We believe that the data of the present study will be useful to the orthopaedician during the procedures like arthroplasty of the total knee, patellofemoral arthroplasty, resurfacing of patella, and designing the prosthetic implant.

The Paracondylar Skull Base: Anatomical Variants and Their Clinical Implications.

AIM: The knowledge of the vasculature around the paracondylar region is important in neurosurgical procedures such as the paracondylar and lateral supracondylar approaches. The objectives of the present study were to determine the prevalence of paracondylar emissary foramina in the adult skull bases and to study the morphology of condylar canals and hypoglossal canals. MATERIAL AND METHODS: The present study included 48 adult human skulls that were obtained from the gross anatomy laboratory of our institution. The paracondylar region was macroscopically observed for the variant foramina, canals and grooves. RESULTS: It was observed that the paracondylar emissary foramen was present in 16 skulls (33.3%). The foramen was found bilaterally in 7 skulls (14.6%) and unilaterally in 9 skulls (18.7%). The hypoglossal canal was single in 35 (72.9%) skulls, double in 11 skulls (22.9%), and triple in 2 skulls (4.2%). The paracondylar process (2.1%) and the paracondylar groove (2.1%) were seen in 1 skull each. The posterior condylar canal was found to be patent in 19 (39.6%) skulls. CONCLUSION: The present study observed that, the paracondylar emissary vein is not rare in occurrence as it is observed in 33.3% of cases. The identification of the paracondylar emissary veins and accessory vessels is important to avoid dangerous bleeding during the surgery. The morphological knowledge of the foramina around the paracondylar region is enlightening to the chiropractors, neurosurgeons and radiologists.

Morphology and topography of the parietal emissary foramina in South Indians: an anatomical study.

The objectives of the present study were to study the prevalence of the parietal emissary vein in adult South Indian population and to study the distance of foramen from the sagittal suture. There were 58 adult human skulls in the present study which were available at the anatomy department of our institution. The study included 116 parietal bones which have been observed macroscopically for the number, prevalence and topography of the emissary foramen. The emissary foramen was present in 83 parietal bones (71.5%) of the present study. It was present at the junction between the middle 1/3 and posterior 1/3 region of the parietal bone. The foramen was observed solitary in 73 parietal bones (62.9%), double in 8 bones (6.9%), and triple in 2 parietal bones (1.7%). The foramen was not observed in 33 parietal bones (28.4%). The bilateral absence of parietal emissary foramen was seen in 7 skulls (12.1%). It was absent unilaterally in 19 skulls (32.7%). The accessory foramina were seen in only 8 skulls (13.8%). The mean distance of the foramen from the sagittal suture was 6.7±2.9 mm and 6.8±2.8 mm on the right and left sides respectively. The prevalence of parietal emissary vein in the present study was 71.5%. The present study has observed important data about the morphology and morphometry of the parietal emissary vein in South Indian population. The identification of parietal emissary veins and accessory veins is important in the operation room to prevent the blood loss.

Predicting lumbar central canal stenosis - a magnetic resonance imaging study.

BACKGROUND: Low back pain is a common complaint among adults, worldwide. Lumbar canal stenosis is frequently diagnosed as a cause for low back pain. In this study we evaluate morphometric measures using MRI sections to predict the occurrence of lumbar central canal stenosis. SETTINGS AND DESIGN: One hundred and fifty four lumbar spinal MRI sagital and axial section images, 77 males and females each were evaluated from the Department of Radiology, Kasturba Medical College, Mangalore, Manipal University. The study design was a prospective study. MATERIALS AND METHODS: Various measurements were taken and two constant ratios were calculated. The Canal Body Ratio and the Ratio between the area of the dural sac and the vertebral body was evaluated. STATISTICAL ANALYSIS: Unpaired t-test analysis was conducted using SPSS software. RESULTS: A canal body ratio less than 0.6 from L1 to L3 levels and less than 0.5 at L4 and L5 levels were found. The ratio between area of dural sac and vertebral body was found to be a constant at 0.2 at all levels. It was found that maximum central canal stenosis occurred at the L5 lumbar vertebral level in 15.6% males and 13% females. This was followed by stenosis at the L4 and L3 lumbar vertebral levels with 5.1% males having stenosis at both levels and 3.9% and 5.1% females in L4 and L3 lumbar levels respectively. CONCLUSION: These morphometrical findings of the lumbar vertebrae could be of use in evaluating the possible cases of lumbar canal stenosis.

Mastoid emissary foramina: an anatomical morphological study with discussion on their evolutionary and clinical implications.

The identification of mastoidal emissary veins is of importance in the neurosurgical practice to diagnose abnormal and normal structures. In the present study, the objectives were to estimate the prevalence rate of mastoidal emissary foramina in the temporal bones of the adult skull and to study their number and morphology. The present study included 48 adult human skulls which were obtained from the gross anatomy laboratory of our institution. The mastoid parts of 96 temporal bones were macroscopically observed for the prevalence, number and morphology of the emissary foramina. It is observed that, the mastoidal emissary foramen was present in 88 temporal bones (91.7%) of our specimens. The foramen was observed single in 60 temporal bones (62.5%), double in 22 bones (22.9%), and triple in 6 temporal bones (6.2%). The mastoidal emissary foramen was absent in 8 (8.3%) temporal bones. The foramen was bilaterally absent in 3 (3.1%) skulls. It was unilaterally absent in 2 (2.1%) skulls and both were on the left side. The mastoidal emissary vein is prevalent in a large number (91.7%) of cases. It was observed that the accessory mastoidal emissary foramina were present in 29.1% of cases. Recognition of the mastoid emissary veins and accessory mastoid emissary veins during the otologic surgery is critical to avoid the significant bleeding. In the neurosurgical practice, the knowledge is important due to variability in the number of mastoidal emissary veins and their connection to the venous sinuses.

In vivo morphometry of menisci of the knee in South Indians: a preliminary study.

BACKGROUND: Since the in vivo morphometric data on the menisci of the knee joint of Indian subjects are scarce, we hereby studied the width and thickness of the menisci using Magnetic Resonance Imaging (MRI) to establish standard dimensions of the normal medial and lateral meniscus as an aid to orthopaedic surgery. METHODS: Eighty menisci from 40 knee joints were analysed in each of three regions, the anterior horn, the mid body and the posterior horn. The thickness and width of the menisci were measured in sagittal and coronal T1-weighted and T2-weighted MRI images and analysed statistically. RESULTS: The mean thickness of medial meniscus at the anterior horn, mid body, and posterior horn were 6.3 ± 1.1 mm, 5.2 ± 1.3 mm, and 6.9 ± 1.1 mm, respectively. The respective values for the lateral meniscus were 4.8 ± 0.7 mm, 6.4 ± 1.1 mm, and 7.0 ± 0.9 mm. The mean width of medial meniscus at the anterior horn, mid body, and posterior horn were 10.5 ± 1.2 mm, 7.8 ± 1 mm and 13.9 ± 0.9 mm, respectively. The widths of lateral meniscus at the same regions were 11.8 ± 1.4 mm, 8.6 ± 1.2 mm, and 12.0 ± 0.9 mm, respectively. The lateral meniscus was significantly wider than medial at the anterior horn and mid body (p = 0.00). In contrast, the posterior horn of medial meniscus was significantly wider than lateral meniscus. Both menisci were significantly wider at their posterior horn, followed by the anterior horn and were significantly narrower at their mid body. CONCLUSION: The present study provides new information on the meniscal thickness and width in South Indians that can be used in planning of orthopaedic and arthroscopic surgeries of the knee joint. However, the study needs to be analyzed with a large sample size for the better interpretation.

Variant origins of arteries in the carotid triangle - a case report.

The left superior laryngeal artery was observed arising from the external carotid artery instead of the superior thyroid artery in the cadaver of an approximately 70 year-old Asian man. In addition, on the same side, the superior thyroid artery arose from the common carotid artery 2 cm before the bifurcation instead of its usual origin from the external carotid artery. From the external carotid artery, the lingual and facial arteries arose from the common linguofacial trunk. The nerves in the carotid triangle were normal in course. No variations were observed on the right side carotid system. The multiple variations in this case have not been previously described. The embryogenesis of this combination of variations is not clear, but the anatomic consequences may have important clinical implications. As angiography has gained popularity in diagnostic approaches in recent years, it is essential to be aware of these variations so that they are not overlooked in differential diagnoses.

Occipital condyle morphometry and incidence of condylus tertius: phylogenetic and clinical significance.

PURPOSE: The objectives were to study the morphometry of occipital condyles and to find the incidence of third occipital condyle in Indian skulls. MATERIALS AND METHODS: In the present study, 140 occipital condyles from 70 dry skulls were analysed. The length, width, height of occipital condyles, the anterior and posterior intercondylar distances was measured. RESULTS: The average length, width and height of occipital condyle were 21.9 mm, 11.26 mm and 10.2 mm respectively. The average anterior and posterior intercondylar distances were 18.7 mm and 38.7 mm respectively. Among our specimens, 2 skulls (2.86%) had a third occipital condyle. CONCLUSION: We believe that the data of the present study may provide anatomical reference to neurosurgeons and thus help in surgical procedures around the craniovertebral junction. The clinical and phylogenetic significance of the third occipital condyle has been discussed.

Morphological analysis and morphometry of the foramen magnum: an anatomical investigation.

AIM: The objectives were to study the morphology of the foramen magnum in dry skulls and to evaluate its antero-posterior diameter, transverse diameter and the foramen magnum index. MATERIAL AND METHODS: The foramen magna of 53 dry human cadaver skulls that were obtained from the neuroanatomy laboratory were examined. Different shapes of the foramen magnum were macroscopically noted and classified. The antero-posterior and transverse diameters were measured and the average foraminal index was calculated. RESULTS: The foramen magnum shapes were determined as a round shape in 22.6% of cases, egg shape in 18.9%, tetragonal in 18.9%, oval in 15.1%, irregular in 15.1%, hexagonal in 5.6% and pentagonal in 3.8% of the cases. In 20.7% of skulls, the occipital condyle was observed to protrude into the foramen. The mean antero-posterior and transverse diameter of the foramen magnum was determined as 31 ± 2.4 mm and 25.2 ± 2.4 mm respectively. The average foramen magnum index was 1.2 ± 0.1. CONCLUSION: The present study has determined the various shapes of foramen magnum and its morphometry. The data obtained may be of useful to the neurosurgeon in analyzing the morphological anatomy of craniovertebral junction. The findings are also enlightening for the anthropologists, morphologists and clinical anatomists.

Morphological and topographical anatomy of nutrient foramina in human upper limb long bones and their surgical importance.

OBJECTIVES: To study the morphology and topography of nutrient foramina and to determine the foraminal index of the upper limb long bones. MATERIALS AND METHODS: The study comprised 243 upper limb long bones, which included humeri, radii, and ulnae. The nutrient foramina were identified macroscopically in all the bones and an elastic rubber band was applied around these foramina. The bones were photographed with the digital camera and foramen index was calculated. Each bone was divided into five equal parts and was analyzed topographically. RESULTS: From our observations, 93.8% of the humeri had single nutrient foramen. The double foramen was observed in 3.1% of the cases and the foramen was found absent in 3.1% of the humeri. In case of radius, 94.4% had single foramen, 1.4% had double foramen, and in 4.2% of the cases it was absent. With respect to ulna, all the 75 bones had single foramen. The mean foraminal index was 57.6 for the humerus, 34.4 for both the ulna and radius. The majority (70%) of the foramina in humerus were located at the 3/5th part, 83.6% of the ulnae foramina at the 2/5th part and 87.7% of the radii foramina at the 2/5th part. CONCLUSIONS: The study has provided additional information on the morphology and topography of nutrient foramina in upper limb long bones. The knowledge about these foramina is useful in certain surgical procedures to preserve the circulation. As microvascular bone transfer is becoming more popular, a convention for the anatomical description of these foramina is important.

Double non coronary aortic sinuses: an autopsy case finding showing the arterial variation / Senos aórticos dobles, no coronarios: un caso de autopsia que demuestra la variación arterial

We report a case of variant origin of the right coronary artery from the left posterior aortic sinus. This was observed routinely during a medico legal autopsy of a 58 year old male who died in a road traffic accident. Initially it was believed that the right coronary artery was absent since there was no obvious right coronary artery ostium from the anterior aortic sinus. However it was found later that the right coronary ostium was present just beside the left coronary ostium in the left posterior aortic sinus and the right coronary artery was arising from the left posterior aortic sinus. The right coronary artery had an intramural course between the aorta and pulmonary trunk, which is considered as very dangerous and life threatening. We believe that the present case report will be enlightening to the cardiologist and cardiothoracic surgeon. It is also true that the conduction of medico legal autopsies of coronary arteries is important for the medico legal resolution.

Se presenta un caso de variación de origen de la arteria coronaria derecha desde el seno aórtico posterior izquierdo. Esto se observó de forma rutinaria durante una autopsia médico-legal de un hombre de 58 años que murió en un accidente de tránsito. Inicialmente se creía que la arteria coronaria derecha estaba ausente ya que no había un ostium observable desde el seno aórtico anterior. Sin embargo, se descubrió más tarde que el ostium de la arteria coronaria derecha estaba presente justo al lado del ostium de la arteria coronaria izquierda en el seno aórtico posterior izquierdo y la arteria coronaria derecha se originaba del seno aórtico posterior izquierdo. La arteria coronaria derecha presentó un recorrido intramural entre la aorta y el tronco pulmonar, que se considera como muy peligroso y potencialmente mortal. Creemos que el presente trabajo será esclarecedor para el cardiólogo y el cirujano cardiotorácico. También consideramos que el conocimiento de la anatomía de las arterias coronarias es importante durante el desarrollo de la autopsia médico-legal para lograr alcanzar una correcta resolución del proceso medicolegal.