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Ibrahim Tekdemir

Publications and source records attributed to Ibrahim Tekdemir.

46 records · Page 3Linked to original sources
PubMed2003

Reliability of the safe area for the superior gluteal nerve.

The authors investigated the reliability of the safe area, which previously was defined to prevent injury to the superior gluteal nerve during the lateral approach to the hip, and its relation to body height. The distance between the point of entry of the superior gluteal nerve into the gluteus medius muscle and the greater trochanter, in the regions which were defined as the anterior and posterior halves of the muscle, were measured in 23 cadaveric hips. There was a significant correlation between the height of the cadavers and the distance in the anterior and posterior regions. In all of the anterior regions and 78% of the posterior regions of the hips, the superior gluteal nerve as found to be in the safe area. The current study showed that the average distance between the innervation point of the gluteus medius muscle and the greater trochanter might change as a function of body height. The risk of damage to the superior gluteal nerve may be higher if the direct lateral approach to the hip is used. These data show that it is possible that the safe area is not always safe.

Body Height↗
PubMed2003

Duplication of the abducens nerve at the petroclival region: an anatomic study.

OBJECTIVE: During its course between the brainstem and the lateral rectus muscle, the abducens nerve usually travels forward as a single trunk, but it is not uncommon for the nerve to split into two branches. The objective of this study was to establish the incidence and the clinical importance of the duplication of the nerve. METHODS: The study was performed on 100 sides of 50 autopsy materials. In 10 of 11 cases of duplicated abducens nerve, colored latex was injected into the common carotid arteries and the internal jugular veins. The remaining case was used for histological examination. RESULTS: Four of 50 cases had duplicated abducens nerve bilaterally. In seven cases, the duplicated abducens nerve was unilateral. In 9 of these 15 specimens, the abducens nerve emerged from the brainstem as a single trunk, entered the subarachnoid space, split into two branches, merged again in the cavernous sinus, and innervated the lateral rectus muscle as a single trunk. In six specimens, conversely, the abducens nerve exited the pontomedullary sulcus as two separate radices but joined in the cavernous sinus to innervate the lateral rectus muscle. In 13 specimens, both branches of the nerve passed beneath the petrosphenoidal ligament. In two specimens, one of the branches passed under the ligament and the other passed over it. In one of these last two specimens, one branch passed over the petrosphenoidal ligament and the other through a bony canal formed by the petrous apex and the superolateral border of the clivus. In all of the specimens, both branches were wrapped by two layers: an inner layer made up of the arachnoid membrane and an outer layer composed of the dura during its course between their dural openings and the lateral wall of the cavernous segment of the internal carotid artery. This finding was also confirmed by histological examination in one specimen. CONCLUSION: Double abducens nerve is not a rare variation. Keeping such variations in mind could spare us from injuring the VIth cranial nerve during cranial base operations and transvenous endovascular interventions.

Abducens Nerve↗
PubMed2003

Closed posterior superior iliac spine impeding pediculocorporeal S-1 screw insertion.

OBJECT: Placement of pedicle screws into S-1 is difficult. In cases in which there is a closed posterior superior iliac spine (PSIS), its medial situation prevents lateral oblique placement of the screw inserter sleeve and directing the screw to the anteromedial aspect of S-1. In the present study, the authors discuss anatomical variations of the PSIS and sacrum, and they describe a safe and effective S-1 screw insertion technique. METHODS: The relation of 50 PSISs obtained from 25 dry pelvises (15 male and 10 female cadavers) was examined. The distance from the inferolateral aspect of the S-1 superior articular facet to its promontory was estimated. The relation between the point of anterior penetration of the "screw line" and "safe zone" was analyzed. Penetration of screw lines into the S-1 body was also measured. (An illustrative case of closed PSIS is presented with pre- and postoperative computerized tomography [CT] scan findings.) The authors found that that PSIS was situated in 28% of the specimens. When screws were directed anteromedially, the screw lines failed to penetrate the S-1 body in 24% of the male and in 15% of female specimens. The screw lines deviated from the safe zone anteriorly in 34% of the male and in 20% of the female specimens. When the PSIS was medial to the line that connects the inferolateral aspect of the S-1 superior articular facet to the promontory, a classification of closed PSIS was assigned. CONCLUSIONS: The accuracy of the placement of the screws and their pullout strength are increased when using the present technique. Preoperative CT scanning should be performed to determine the presence of a closed PSIS; in cases in which a closed PSIS is found, the ilium should be resected to enable a greater anteromedial trajectory for placement of S-1 pedicle screws.

Adult↗
PubMed2002

Avulsion of the tibial tuberosity with a lateral plateau rim fracture: case report.

An avulsion fracture of tibial tuberosity with an unusual articular involvement was treated with open reduction and internal fixation. Although the mechanism of tibial tuberosity fracture is described as passively flexing the knee while active quadriceps femoris contraction, the weight transmitted from the menisci on the lateral side of the knee joint may cause an epiphyseal disruption. We report a case of tibial tuberosity fracture with lateral plateau rim fracture in a young male adolescent, which has not been published previously in the literature.

Adolescent↗
PubMed2002

Anatomical landmarks regarding sacrospinous colpopexy operations performed for vaginal vault prolapse.

AIM: To investigate the anatomical relationships of the structures and the topographic anatomy of the sacrospinous ligament and validate current anatomic knowledge of this area. MATERIALS: Nine embalmed half female cadaver pelvises were dissected to reveal the anatomy of the sacrospinous ligament. RESULTS: The average length of the sacrospinous ligament was measured to be 43.04 +/- 6.58 mm. The inferior gluteal complex emerges from the infrapiriform foramen at a distance of 17.02 +/- 3.08 mm from the ischial spine and courses to inferior-laterally with a slight curve. During this course, it passes close to the upper-lateral half of the sacrospinous ligament. The pudendal complex passes above the spine in six of the nine cases (66.6%) and lies maximum of 5.5 mm medial to the spine. On average the sciatic nerve is measured to be 25.14 +/- 3.94 mm lateral to the ischial spine. CONCLUSION: Placing the suture inferomedially and close to sacrum, the risk of complication will be minimal.

Cadaver↗
PubMed2002

Dural and arachnoid membraneous protection of the abducens nerve at the petroclival region.

The goal of this study was to determine the membranous protection of the abducens nerve in the petroclival region. The petroclival portion of the abducens nerve was studied in ten dissections from five cadaveric head specimens. One of the heads was used for histological sections. Four heads were injected with colored latex for microsurgical dissections. The histological sections were prepared from petroclival dura mater, embedded in paraffin blocks, stained, sectioned in the axial, coronal, and sagittal planes, and evaluated by light microscopy. The abducens nerve was covered by a dural sleeve and arachnoidal membrane during its course within the petroclival area. Following the petrous apex, the abducens nerve was fixed by a sympathetic plexus and connective tissue extensions to the lateral wall of the cavernous segment of the internal carotid artery and to the medial wall of Meckel's cave. Fibrous trabeculations inside the venous space were attached to the dural sleeve. The lateral clival artery accompanied the dural sleeve of the abducens nerve and supplied the petroclival dura mater. The arterioles accompanying the abducens nerve through the subarachnoid space supplied the nerve within the dural sleeve. The arachnoid membrane covered the abducens nerve within the dural sleeve to the petrous apex, and arachnoid granulations found on the dural sleeve protruded into the venous space. The extension of the arachnoid membrane to the petrous apex and the presence of arachnoid granulations on the dural sleeve suggest that the subarachnoid space continues in the dural sleeve.

Journal Article↗
PubMed2002

Should we reevaluate the variables for predicting the difficult airway in anesthesiology?

UNLABELLED: Anesthesiologists have often been confronted with the difficult question of determining which patient will present an increased difficulty for endotracheal intubation. The limits of the previously reported morphometric airway measurements for predicting difficult intubation have inadequately addressed the normal patient population variables. We designed this prospective study to investigate the age and sex-related changes in the morphometric measurements of the airway in a large group of patients without anatomic abnormality and a group of cadavers. Hyomental, thyromental, sternomental distances, neck extension, and Mallampati scores were evaluated in 12 cadavers and in 334 patients. Patients were allocated to three groups based on age: Group 1 (20-30 yr), Group 2 (31-49 yr), and Group 3 (50-70 yr). Male and female sex differences were also evaluated. Hyomental distance was the only variable not affected by age. In addition, the mean population values were less than the threshold values suggested as criteria for difficult endotracheal intubation. All the other criteria were age-dependent and inversely affected by the increase in age. Male sex was also a distinction for increased measurements of all the morphometric distances. The mean degree of neck extension was similar in both sex groups. This study provides a more comprehensible approach to the morphometric measurements of the human airway. Adequate data of normal values may help the clinician to identify patients that are outside the range and therefore may be challenging. IMPLICATIONS: This study was performed to establish data on the average values of airway morphology in the adult population of different age groups and sex. Hyomental, thyromental, sternomental distances and neck extension values were measured on 12 cadavers and 334 patients.

Adult↗
PubMed2002

The V-Y island dorsal nasal flap for reconstruction of the nasal tip.

The dorsal nasal flap and its modifications have proved reliable in the coverage of defects on or adjacent to the tip of the nose. However, the problems inherent in the nature of the flap are limited rotational movement afforded by the pedicle, visible scars crossing the dorsum and the natural concavity of the alar crease, skin thickness discrepancy between the flap and the skin, and dog-ear deformity created by the rotation. The purpose of this study was to design a new modification of the dorsal nasal flap, in the highlight of a cadaveric study, that can overcome the traditional drawbacks. Ten adult human cadavers were used to study the vascular basis of the flap and to simulate application of the flap. Cadaveric dissections demonstrated that a skin island over the nasal dorsum and glabellar area can be elevated safely based on a dual axial supply (i.e., the terminal branches of the angular artery and vein bilaterally), and can be advanced easily in a V-Y manner to cover the nasal tip defect. The result obtained in the clinical case showed that the V-Y island dorsal nasal flap provided a sizable amount of skin with more appropriate texture and color for coverage of the nasal tip defect without tension or secondary deformity.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Spinoglenoid septum: a new anatomic finding.

The spinoglenoid ligament has been implicated in compression of the suprascapular nerve in cases with isolated atrophy of the infraspinatus muscle. We dissected 32 shoulders of 16 embalmed cadavers. We could detect a spinoglenoid ligament in only 5 shoulders, and it was thin, loose, and weak. Instead of the spinoglenoid ligament, we observed a septum formed by the thickening of the fascial cover of the distal third of the supraspinatus and infraspinatus muscles. It originated from the spinoglenoid notch and extended into the posterior capsule. We named this structure the spinoglenoid septum. The suprascapular nerve passed between the bony margin of the spinoglenoid notch and the medial concave margin of the spinoglenoid septum. This septum may be a cause of dynamic compression of the suprascapular nerve.

Fascia↗