Some structures of the human body still remain controversial or incompletely described.
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Brachial Plexus↗
Biomedical subjects
I Tekdemir
Publications and source records attributed to I Tekdemir.
The innervation of patella: anatomical and clinical study.
As much interest has been focused on afferent innervation of knee than that of patella, there are few articles about patellar innervation. But in clinical practice anterior knee pain due to patellar disorders is a quite frequent problem. Our aim was to review the innervation pattern of patella and to give the topographic anatomy of the nerves. We dissected 30 knees of 15 formaldehyde-fixed cadavers. Two nerves from vastus medialis and lateralis were found to reach patellar edge. Apart from these, we were unable to find any other neural structures around patellae. Mean distances between the tuberosity of the tibia and medial and lateral nerve entry points were 90.1(range 74-102) and 96.3 mm (range 76-109), respectively. The angles between lines which join the entry points of nerves and vertical line to the center point of patella were measured in frontal plane. It was approximately 60 degrees medially and 40 degrees laterally. To confirm that these nerves are patellar pain afferents, we performed a local anesthesia test in 32 knees of 20 patients with patellofemoral pain. Clinically, there was a significant difference between the visual analogue scale (VAS) scores before and after local anesthetic injections (p<0.01). Previous studies have emphasized especially the medial innervation. We found that both superomedial and superolateral nerves were important for patellar innervation. We described precisely the entry points of these nerves to patella for selective denervation.
Adult↗
Muscle variations and abnormal branching and course of the ulnar nerve in the forearm and hand.
During dissection of the right forearm of a 27-year-old female cadaver, variations in the form and insertion of the palmaris longus muscle were observed. The tendon of the palmaris longus muscle, which demonstrated a centrally placed belly, split into two tendons: one inserted into the palmar aponeurosis and the other into the proximal part of the flexor retinaculum. Additionally, we found an accessory muscle extending between the flexor retinaculum and the tendon of the abductor digiti minimi muscle. This accessory muscle was located deep to the ulnar artery but superficial to the superficial and deep branches of the ulnar nerve at the wrist. Finally, an aberrant branch of the ulnar nerve was identified in the forearm; it traveled distally alongside the ulnar artery and in the palm demonstrated communications with common palmar digital nerves from the ulnar and the median nerves. No variations were observed in the contralateral upper limb.
Adult↗
Internal anal sphincter: an anatomic study.
The anatomy of the internal anal sphincter and surrounding structures was investigated in 24 cadavers using a surgical microscope (6-25 x magnification). An understanding of the anatomy of the internal anal sphincter is helpful in avoiding complications during surgical procedures in the anorectal region. The external anal sphincter was composed of three ellipsoid rings of skeletal muscle (subcutaneous, superficial, and deep) that encircle the anal canal; in contrast, we found that the internal anal sphincter was composed of flat rings of smooth muscle bundles stacked one on top of the other, like the slats of a Venetian blind. In each anal canal, the average number of ring-like slats observed was 26.33 +/- 2.93 (range = 20-30) and each was covered by its own fascia. The smooth muscle fibers and fascia coalesced at three equidistant points around the anal canal to form three columns that extended distally into the lumen and differed in form from the other anal columns. When viewed from an anterior position, the columns were located anteriorly at the observer's right (5 o'clock position), posteriorly at the right (1 o'clock position), and laterally at the left (9 o'clock position). This heretofore unreported anatomy of the internal anal sphincter may play an important role in closing off the lumen of the anal canal and maintaining bowel continence.
Anal Canal↗
Fossa navicularis: anatomic variation at the skull base.
The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were <2 mm in depth and the other 14 had a depth of >/=2 mm. Of the 525 patients, 16 (3.0%) were identified as having a fossa navicularis in CT images. Evaluation of MRIs showed no soft tissue lesions in any of these patients. Comprehensive anatomic details of the fossa navicularis have not been reported in the literature. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base.
Bone Cysts↗
Evaluation of the anterior and posterior ethmoidal canal by computed tomography.
AIM: To examine the anatomy, length and angulation of the anterior and posterior ethmoidal canals (AECs and PECs) using computed tomography (CT), and to determine the anatomical landmarks in which the canals are expected to be seen in transverse and coronal planes. MATERIALS AND METHODS: CT images of 150 patients were analysed. One, 2, and 3 mm thick sections were obtained separately in axial and coronal images. The frequency of visualization of the AECs and PECs, and if present, a third canal, was noted. The course and the angulation of the AEC and the PEC in transverse and coronal planes were recorded. On axial sections the distance between the AEC and PEC and the previously defined landmarks were measured. On coronal images, the distances were calculated from the thickness of the cross-section and the number of sections between the various structures. RESULTS: The AEC was identified as a separate canal in 84% of patients, and was embedded in the ethmoid roof in 16%. The PEC was seen as a separate canal in 8% and was present in the ethmoid roof in 92%. On the 1 mm thick coronal and transverse sections, a third canal was identified at the junction of the middle and posterior third of the AEC-PEC distance in both of the images. The average lengths of these canals were 4-12 mm (mean 8.2 mm) for the AEC, and 2-13 mm (mean 7.6 mm) for the PEC. CONCLUSIONS: To avoid the complications that can develop during endoscopic sinus surgery; the course, length and the angulations of the anterior and posterior ethmoidal arteries and their canals can be identified by CT in standard positions if a sufficiently thin section thickness is used. The present study has shown the exact CT localization of the AECs and PECS, which are frequently overlooked when evaluating para-nasal sinuses.
Adult↗
Accurate course and relationships of the transverse facial artery in human cadavers.
Both the course and localization of the transverse facial artery are described, based upon the bilateral dissection of heads from 20 human cadavers. Its anatomical relationships with the mandibular fossa, the articular tubercle, the zygomatic arch, the parotid duct and the maxillary artery are studied and morphometric features are calculated. Furthermore, the transverse facial territory was examined. This territory was supplied by a single perforating branch in 28 cases, by two perforating branches in 10 and by three perforating branches in 2. Knowledge of the course and relationships of the transverse facial artery should help to protect this artery from the risk for transection. However, the variable course of the transverse facial artery must always be taken into consideration by the clinicians during surgical procedures.
Adult↗
A clinical case and anatomical study of the innervation supply of the vastus medialis muscle.
The innervation supply to the vastus medialis (VM) muscle, a component of quadriceps femoris (QF), is provided by a branch of the femoral nerve (FN) running along the muscle. The course of the nerve from lumbar roots to the muscle has been described by many researchers. It is known to ride along the femoral vein, artery and saphenous nerve and enter the adductor canal (Hunter's canal), and then to divide into branches that supply vastus medialis and the knee joint. Femoral mononeuropathy is uncommon, and is usually due to compression in the spinal level. Hematoma in the psoas and iliacus muscles, drug abuse, lithotomy position and limb lengthening are the other associated reasons for a mononeuropathy of the femoral nerve. Isolated vastus lateralis (VL) atrophies have been reported by a few authors, suggesting that compression of the nerve and direct violation of the nerve with injections might be the reason for mononeuropathy. Isolated VM atrophy has not been previously reported. The purpose of the study was to identify the anatomical structures around the FN branch which innervates the VM muscle.
Adolescent↗
Details of fibroligamentous structures in the cervical unco-vertebral region: an obscure corner.
Vertebral bone, joints and ligaments on the cervical spine are structures that maintain the stability of the spine and protect the neurovascular structures. Determining the detailed anatomical location of the intervertebral foramen and unco-vertebral (UV) region with respect to the vertebral bone, joint and ligaments is critical when choosing the safest surgical approach to the cervical spine. We studied the microscopic detailed anatomy of the dural covering and posterior longitudinal ligament (PLL) in eight cadaver specimens and the relevance of these structures in the UV region from C4 to C7. The uncinate process (UP) and its covering ligaments are mechanical barriers that prevent the nerve root and the vertebral artery against unintentional surgical damage. Dissection at the posterolateral surface of the UP revealed a separate perivascular fibroligamentous tissue (PVFLT) that originates from the PLL. The recognition of the PVFLT may provide for safe surgery by protecting the neural and vascular structures during decompression in the UV region.
Aged↗
Epipteric bones in the pterion may be a surgical pitfall.
BACKGROUND: The pterion, the most commonly used neurosurgical landmark, is defined as the junction of frontal, parietal, and greater wing of the sphenoid and the squamous part of temporal bones. Our aim was to identify the variations of the pterion which may be a potential surgical pitfall. METHODS: Both sides of 300 adult skulls were examined but 110 sides were eliminated since their pterion could not be identified owing to a damage. The shortest distance between the lateral orbital rim and the most anterior junction of the four bones forming the pterion was measured on all sides. RESULTS: Out of 490 sides the pterion was found to contain epipteric bones in 44 (9 %), and in these skulls the most anterior junction of the bones may be as close as 16 mm to the lateral orbital rim. CONCLUSION: In skulls with an epipteric bone variation, particularly the anterius and proprium types; the pterion can mistakenly be assessed to be at the most anterior junction of bones and a burr hole placed over there may cause inadvertent penetration into the orbit.
Adult↗
Innervation pattern of the abductor digiti minimi muscle of the hand.
This cadaver study investigated the innervation patterns of the abductor digiti minimi in Guyon's canal. There was only one branch to the abductor digiti minimi in 22 of the 30 specimens. Two branches were found in three hands, and three branches in two. Three other variations were documented.
Adult↗
The effect of changing pressures on dural puncture and leak with various spinal needles on an in vitro model.
Postdural puncture headache is one of the most serious complications of spinal anesthesia. In this study, spinal needles of various types and shapes were used to investigate the amount of fluid leakage in dural puncture under various levels of pressures. Dura samples received from 10 cadavers were fixed in an in vitro model. The dural punctures were inflicted with 22 G, 25 G, and 27 G Quincke; 25 G Withacre; 25 G, 27 G Pencan, and 26 G Atraucan spinal needles. The fluid, which leaked during the process, was collected under the pressures of 0, 25, 50, 100, and 150 cm H(2)O in one-hour period for each level. The holes in the dura were studied under light microscope. While 22 G and 25 G Quincke needles were used, the fluid leakage directly correlated the amount of liquid, the diameter of the needle, and the pressure used. The puncture of 25 G Withacre and 25 G Pencan presented a leakage which did not significantly vary with the liquid pressure and was of lesser amount. In 26 G Atraucan, 27 G Pencan, and 27 G Quincke inflicted punctures, little liquid was collected and it did not vary with differing pressures. Thus, no significant correlation was established between the needle diameter and the puncture. It was concluded that the sharp-ended needles could not endure changes in the pressure. However, those needles with a very thin diameter and a pencil tip were considered as safe tools for anesthetical practices.
Aged↗
The effect of carnitine on random-pattern flap survival in rats.
Carnitine is an endogenous cofactor involved in the transport of long-chain fatty acids into the mitochondria where they undergo beta-oxidation. Through another reaction, carnitine produces free coenzyme A and reduces the ratio of acetyl-coenzyme A to coenzyme A, thereby enhancing oxidative use of glucose, augmenting adenosine triphosphate synthesis, and reducing lactate production and acidosis. Because of its regulatory action on the energy flow from the different oxidative sources, especially under ischemic conditions, carnitine has been used in cardiovascular diseases such as coronary heart disease, congestive heart failure, peripheral vascular disease, dyslipidemia, diabetes, and chronic renal diseases with satisfactory results. A flap is also a relatively ischemic tissue and may obtain benefit from carnitine. To investigate this, 30 rats were divided into three groups of 10 animals: a control group and two carnitine-treated groups. Random dorsal skin flaps were elevated on the rats. In the control group, no pharmacologic agents were used. Of the two treated groups, group 1 was treated with 50 mg/kg/day carnitine for 1 week and group 2 was treated with 100 mg/kg/day carnitine for 1 week. The areas of flap necrosis were measured in each group. The median areas of flap necrosis of the groups were 12.55, 9.23, and 4.9 cm2, respectively. There was a statistically significant improvement of flap necrosis in carnitine-treated groups compared with the control group (group 2, p = 0.001; group 3, p = 0.000). Furthermore, there was less necrosis in the high-dose carnitine-treated group than the low-dose carnitine-treated group. As a conclusion, carnitine may have a dose-dependent effect to increase flap survival in random skin flaps.
Animals↗
Corona mortis: an anatomic study in seven cadavers and an endoscopic study in 28 patients.
BACKGROUND: The corona mortis is defined as the vascular connections between the obturator and external iliac systems. While detailed information on the arterial anastomoses in corona mortis is available, a complete description of the venous system is lacking. Although the tiny anastomoses behind the pubic symphysis between the obturator and external iliac arteries have been described in classical anatomy textbooks, these texts neglect to mention that these anastomoses can be life threatening. Attention needs to be paid to these anastomoses between the arterial and the venous system located over the superior pubic ramus during laparoscopic procedures. METHODS: Fifty retroinguinal regions were dissected in seven cadavers and 28 patients. RESULTS: During the dissections, a venous anastomosis on the superior pubic ramus was a consistent finding in 96% of cases. This vein coursed vertically to the inferior border of the superior pubic ramus and connected to the obturator vein. Accessory branches of the obturator artery were observed in only 8% of the dissections. The tiny connections between the obturator and external iliac arteries are less important, since their diameter is <1 mm. CONCLUSIONS: We have termed the venous connection between the external iliac and obturator veins over the superior pubic ramus "the communicating vein". This structure forms the corona mortis. Surgeons dealing with direct, indirect, femoral, or obturator hernias need to be aware of these anastomoses and their close proximity to the femoral ring. In classical anatomy textbooks, a description of the veins that form corona mortis is found less often than descriptions of the arteries. Since a venous connection is more probable than an arterial one, its importance must be appreciated by surgeons in order to avoid venous bleeding.
Cadaver↗
Lumbar pedicle: surgical anatomic evaluation and relationships.
Although several clinical applications of transpedicular screw fixation in the lumbar spine have been documented for many years, few anatomic studies concerning the lumbar pedicle and adjacent neural structures have been published. The lumbar pedicle and its relationships to adjacent neural structures were investigated through an anatomic study. Our objective is to highlight important considerations in performing transpedicular screw fixation in the lumbar spine. Twenty cadavers were used for observation of the lumbar pedicle and its relations. After removal of whole posterior bony elements including spinous processes, laminae, lateral masses, and inferior and superior facets, the isthmus of the pedicle was exposed. Pedicle width and height (PW and PH), interpedicular distance (IPD), pedicle-inferior nerve root distance (PIRD), pedicle-superior nerve root distance (PSRD), pedicle-dural sac distance (PDSD), root exit angle (REA), and nerve root diameter (NRD) were measured. The results indicated that the average distance from the lumbar pedicle to the adjacent nerve roots superiorly, inferiorly and to the dural sac medially at all levels ranged from 2.9 to 6.2 mm, 0.8 to 2.8 mm, and 0.9 to 2.1 mm, respectively. The mean PH and PW at L1-L5 ranged from 10.4 to 18.2 mm and 5.9 to 23.8 mm, respectively. The IPD gradually increased from L1 to L5. The mean REA increased consistently from 35 degrees to 39 degrees. The NRD was between 3.3 and 3.9 mm. Levels of significance were shown for the P < 0.05 and P < 0.01 levels. On the basis of this study, we can say that improper placement of the pedicle screw medially and inferiorly should be avoided.
Adult↗
Surface landmarks of brachial plexus: ultrasound and magnetic resonance imaging for supraclavicular approach with anatomical correlation.
The present study is able to describe a certain line, under which brachial plexus (BP) lies underneath in the supraclavicular region. A line drawn between midpoint of the sternocleidomastoid muscle to the midpoint of the clavicle was considered for BP. Surface landmarks were evaluated by applying ultrasound (US) on 30 volunteers (15 female, 15 male). Axial and sagittal views of BP were taken and distances between skin and BP were measured. Coronal magnetic resonance (MR) sections were taken from 7 volunteers according to the second line after applying two fat capsules on each line. The sonographic views were seen at the same line. Mean distances from skin were found as 16.5+/-0.7 mm for male and 14.5+/-0.5 mm for female volunteers. MR images were obtained bilaterally, which were parallel and posterior from sonographic lines. Surface landmarks, as presented in this study, are simple to accomplish and are not dependent on structural variations as external jugular vein.
Adult↗
Is the asterion a reliable landmark for the lateral approach to posterior fossa?
An anatomical study was conducted to gain orientation regarding the posterolateral approaches. The asterion is defined as the junction of the lambdoid, parietomastoid, and occipitomastoid sutures. This anatomical point has been widely used as a landmark in lateral approaches to posterior fossa. Although there are many common practices in posterolateral approaches, studies providing accurate anatomical knowledge as to what is the correct point to start a craniotomy are limited in number. Therefore, this study was conducted in an attempt to determine the reliability of the asterion for the posterolateral approaches as surgical landmark.
Adult↗
Comprehensive microsurgical anatomy of the jugular foramen and review of terminology.
The microsurgical anatomy of the jugular foramen was studied in 12 formalin preserved cadavers (24 foramina) and 40 dry-skulls (80 foramina). The jugular foramen was exposed by microsurgical dissection with drilling from a superior to inferior direction. Observations regarding dural architecture of the jugular foramen and relationships between neurovascular structures passing through the foramen were noted in cadavers. Normal bony construction of the foramen and its variational anatomy were examined in dry-skull specimens. Using photographs and drawings, the anatomy of the jugular foramen is presented and related terminology is discussed in the light of a literature review.
Cadaver↗