Alaittin Elhan

Certain Anatomical Relations and the Precise Morphometry of the Infraorbital Foramen–Canal and Groove: An Anatomical and Cephalometric Study

Objectives To determine and to standardize the certain anatomical relations, and the precise size, course, and location of the infraorbital foramen, canal, and groove for facilitating surgical and invasive procedures.

Numerical Study of the Aerodynamic Effects of Septoplasty and Partial Lateral Turbinectomy

Objectives: To investigate, first, the effects of septal deviation and concha bullosa on nasal airflow, and second, the aerodynamic changes induced by septoplasty and partial lateral turbinectomy, using computational fluid dynamics (CFD).

Anatomy of the anterior sacroiliac joint with reference to lumbosacral nerves.

There are no detailed descriptions of the neural structures that may be seen during surgical interventions of the pelvis. Anatomic dissections were performed to see which nerves are endangered in approaches to the anterior sacroiliac joint for plate fixations. Sixty cadavers were dissected bilaterally. Fifty-one were male and nine were female. L4 and L5 nerve roots were followed along the sacroiliac joint from the intervertebral foramen to the entrance into the lesser pelvis. Measurements were made between the nerves and sacroiliac joint from the proximal end of the joint to the pelvic brim. The L4 nerve root and the lumbosacral trunk (and not the L5 nerve root) were the nerves most susceptible to injury because of their course and proximity to the sacroiliac joint. As a result, during the anterior approach and fixation of the sacroiliac joint with plates, extreme care should be taken to identify the L4 nerve root or lumbosacral trunk or both at the anteroinferior third of the joint because the distance between the nerve and the joint is less than 1 cm.

Ultrasound-guided obturator nerve block: a sonoanatomic study of a new methodologic approach.

BACKGROUND: Obturator nerve block is one of the most technically challenging regional anesthesia techniques. Recently, the characteristics of the nerve have been described using ultrasound. However, clinical application of proximal ultrasound-guided obturator nerve block on patients has not been reported. In this study, we used ultrasound to describe the anatomical localization of the obturator nerve and its two branches in cadavers, volunteers, and also patients. METHODS: A hyperechoic triangular shape formed by the superior pubic ramus, posterior margin of the pectineus muscle and anterior aspect of the external obturator muscle containing the obturator vessels and nerve was defined by ultrasound imaging in cadavers. In eight volunteers, bilateral obturator nerve images were obtained and the distances to specific landmarks (femoral artery, femoral vein, and pubic tubercle) were recorded. Ultrasound-guided obturator nerve block was further performed in 15 patients by using the previously defined approach. The final distance of the needle tip to the femoral artery, distances between the needle insertion point to the pubic tubercle and the depth of needle insertion were recorded. RESULTS: The rates of common obturator nerve, anterior and branching obturator nerve pattern visibility with ultrasound were determined in 12/16, 13/16, and 7/16 sites in volunteers, respectively. Mean (sd) values of critical landmarks obtained from volunteers were obturator nerve-femoral vein 12.9 ± 2.9 mm and obturator nerve-pubic tubercle 19.9 ± 2.6 mm. Mean measurements obtained from patients were: femoral artery- needle tip 18.5 ± 2.4 mm, needle depth 48.3 ± 10.4 mm, pubic tubercle- needle insertion point (horizontal) 18.8 ± 2.0 mm, and pubic tubercle- needle insertion point (vertical) 21.1 ± 2.9 mm. Visual analog scale scores obtained from patients at 1 and 24 h were lower compared to baseline values (P < 0.001). Ninety-three percent (14 of 15) of the patients reported satisfaction from the block. CONCLUSIONS: Landmarks defined in this clinical trial can be used in patients for obturator nerve block with ultrasound guidance.

Temporal Branch of the Facial Nerve and Its Relationship to Fascial Layers

OBJECTIVES To eliminate the inconsistency in the nomenclature, to anatomically and definitively describe the topographic relationship of the temporal branch of the facial nerve to the fascial layers and the fat pads, and to create an effective algorithm to define the safest approaches and planes for surgical procedures in this area. METHODS The study was performed using 18 hemifacial cadaveric specimens. In 12 hemifacial specimens, the facial halves were coronally sectioned and dissected. In 6 hemifacial specimens, planar dissection was performed layer by layer. RESULTS The temporal branch of the facial nerve that traversed inside the deep layers of the temporoparietal fascia and the superficial musculoaponeurotic system coursed along the zygomatic arch as 1 (14.3%), 2 (57.1%), 3 (14.3%), and 4 (14.3%) twigs in the specimens. The temporoparietal fascia had no attachment to the zygomatic arch and continued caudally as the superficial musculoaponeurotic system. Adhesions were between the temporoparietal fascia and the superficial layer of the deep temporal fascia around the zygomatic arch. In most specimens, the superficial layer of the deep temporal fascia continued as the parotideomasseterica fascia, and a deep layer abutted the posterosuperior edge of the zygomatic arch. CONCLUSION An easy and safe surgical approach in this area is to elevate the superficial layer deep to the intermediate fat pad directly on the deep layer of the deep temporal fascia descending to the periosteum along the zygomatic arch.

Posterior osseous bridging of C1

The sulcus of the vertebral artery is located behind the lateral mass of the atlas and in some cases is converted into a foramen by anomalous ossification known as the posterior ponticulus (osseous bridge). This study involved anatomical observations of 158 isolated anatomical specimens of dry C1 vertebrae. The incidence and types of posterior osseous bridging were identified for the 158 dry samples of atlas vertebrae. In nine (5.6%) dry C1 vertebrae, partial osseous bridging was detected (bilaterally in eight vertebrae and unilaterally on the left in one). Complete osseous bridging (arcuate foramen) was observed in six (3.8%) dry C1 vertebrae (bilaterally in one vertebra, unilaterally on the left in three, and on the right in two). Awareness of the types of posterior osseous bridging of C1 in craniocervical junction surgery is essential, and may be helpful in surgical interventions in this region.

The jugular foramen: A comparative radioanatomic study

BACKGROUND Advances in microsurgical techniques made possible the removal of advanced jugular foramen (JF) lesions, which once had been accepted as unoperable. However, successful surgery requires detailed knowledge of the JF anatomy. METHODS Sixteen jugular foramina in eight formalin-preserved adult cadavers were scanned with axial and coronal high resolution computed tomography (HRCT) prior to dissection. After craniectomy and removal of brain tissue, the relationships of the neurovascular structures in the JF were determined by drilling the temporal bones from superior to inferior on planes parallel to the skull base. RESULTS No bony partition of the JF was observed. A dural band consistently divided the JF into two parts. Anterior to it was the glossopharyngeal nerve (IX) while the vagus (X) and accessory (XI) nerves were located posteriorly. There was a notch in which the IX nerve entered the JF. It was also identified on the CT scans and defined as the glossopharyngeal recess. The IX nerve made a genu within the JF in all specimens. Then, it ran inferiorly through a bony canal in three specimens (18.75%), and through an incomplete bony canal in two (12.5%), which were also defined on the CT images. The inferior petrosal sinus ran through a sulcus anteromedial to the glossopharyngeal recess. The posterior meningeal artery was found to be located between the X and XI nerves within the JF. CONCLUSIONS This study revealed a complex and highly variable pattern of the relationships of the neurovascular structures in the JF, and their HRCT images correlated well with the anatomic microdissections.

The Annular Ligament An Anatomical Study

Background Despite documentations of ligamentous structures of the elbow, the anatomy and clinical and functional importance of the annular ligament has not been comprehensively defined in the orthopaedic literature. Hypothesis The annular ligament is an important component of both the proximal radioulnar and humeroradial joints, as well as an important component of the neighboring muscles and ligaments. Study Design Descriptive laboratory study. Materials and Methods To investigate the annular ligament and its relationship with neighboring structures, macroscopic and microscopic dissections were performed on both upper extremities of 30 cadavers (12 female and 18 male) fixed in 10% formaldehyde and on 1 upper extremity of a fresh cadaver (male). Results The distal ulnar insertion of discrete fibers on the supinator crest was defined as the inferior oblique band of the annular ligament, and the proximal insertion of the annular ligament was defined as the superior oblique band of the annular ligament. These patterns were noted in all specimens. It was difficult to distinguish the fibers of the supinator muscle in every specimen because they were intimately fused with the fibers of the annular ligament. Conclusions The superior and inferior oblique bands of the annular ligament attached proximally and distally onto the ulna, thus helping to secure the annular ligament in place.

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.

The subarcuate canaliculus and its artery--a radioanatomical study.

The anatomy of the subarcuate canaliculus (SAC), subarcuate fossa (SAF) and subarcuate artery (SAA) was studied in 12 cadavers and 35 dry temporal bones. Each cadaver was scanned with high resolution CT (HRCT) prior to microdissection. The SAC was always found to be a single canal located between the two arcs of the anterior semicircular canal in both microdissections and HRCT scans and the internal acoustic meatus was observed to be located just inferior to the SAC. The SAC was on average of 9.2 mm in length and 1 mm in width. The SAF was situated at a distance of 4.2 mm from the internal acoustic meatus, 3.5 mm from the groove for the superior petrosal sinus, 6.7 mm from the opening of the vestibular canaliculus and 11.5 mm from the most superior part of the jugular foramen. The SAA was found to originate from the anterior inferior cerebellar artery in 9 cadavers and from the internal auditory artery in 3 cadavers. The SAA always emerged from the main artery outside the internal acoustic meatus. It ran through the SAC as a single artery. This study investigated CT correlated anatomical aspects of the subarcuate canaliculus and its artery which is claimed to be responsible for the blood supply of the mastoid antrum, facial canal and bony labyrinth.