Enhanced stability of the distal radioulnar joint with double suture button construct: a cadaveric study.

BACKGROUND: Distal radioulnar joint (DRUJ) instability is a common post-traumatic complication, often leading to chronic pain and dysfunction. Current reconstructive techniques, such as the single suture button construct, offer suboptimal stabilization in certain motions. This study aimed to evaluate whether a double suture button construct provides greater stability than the single construct in a cadaver model of DRUJ instability. We hypothesized that the double suture button construct would more effectively minimize dorsal translation of the radius relative to the ulna. METHODS: We used nine freshly frozen human cadaver upper extremities, destabilized the DRUJ, and then reconstructed the joint using three different suture button constructs: single transverse, double (transverse + oblique), and single oblique. The specimens were secured in a custom-designed testing apparatus to measure dorsal translation of the radius. The study proceeded in five stages: stable DRUJ, unstable DRUJ, and reconstruction using a single transverse, double (transverse + oblique), and single oblique suture button construct. Dorsal translation was measured at neutral, 45° pronation, and 45° supination. Statistical comparisons of mean values were conducted for each stage. RESULTS: Reconstruction with the transverse, transverse plus oblique, and oblique suture button constructs resulted in statistically significant reductions in dorsal translation compared to the unstable DRUJ (p < 0.001 for all). The double-suture button construct significantly minimized dorsal translation in all positions, restoring stability comparable to a stable DRUJ: neutral (p = 1.000), pronation (p = 0.963), and supination (p = 1.000). In contrast, single constructs failed to fully restore stability in pronation and supination. CONCLUSION: The double suture button construct provides significantly greater stabilization of the DRUJ compared to the single construct. These findings suggest that the double construct could be a more effective option for treating DRUJ instability, particularly in restoring normal joint function during various motions. Further research is warranted to confirm these results in clinical settings.

The Effects of Prenatal and Postnatal Exposure to 50-Hz and 3 mT Electromagnetic Field on Rat Testicular Development.

Background and objectives: It has been shown that electromagnetic fields (EMFs) have negative effects on the reproductive system. The biological effects of EMF on the male reproductive system are controversial and vary depending on the frequency and exposure time. Although a limited number of studies have focused on the structural and functional effects of EMF, the effects of prenatal and postnatal EMF exposure on testes are not clear. We aimed to investigate the effects of 50-Hz, 3-mT EMF exposure (5 days/wk, 4 h/day) during pre- and postnatal periods on testis development. Materials and Methods: Pups from three groups of Sprague-Dawley pregnant rats were used: Sham, EMF-28 (EMF-exposure applied during pregnancy and until postnatal day 28), EMF-42 (EMF-exposure applied during pregnancy and until postnatal day 42). The testis tissues and blood samples of male offspring were collected on the postnatal day 42. Results: Morphometric analyses showed a decrease in seminiferous tubule diameter as a result of testicular degeneration in the EMF-42 group. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were decreased in the EMF-42 group. Lipid peroxidation levels were increased in both EMF groups, while antioxidant levels were decreased only in the EMF-28 group. We found decreased levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF1) in the EMF-42 group, and decreased levels of the SRC homology 3 (SH3) and multiple ankyrin repeat domain (SHANK3) in the EMF-28 group in the testis tissue. Conclusions: EMF exposure during pre- and postnatal periods may cause deterioration in the structure and function of testis and decrease in growing factors that would affect testicular functions in male rat pups. In addition to the oxidative stress observed in testis, decreased SHANK3, VEGF, and IGF1 protein levels suggests that these proteins may be mediators in testis affected by EMF exposure. This study shows that EMF exposure during embryonic development and adolescence can cause apoptosis and structural changes in the testis.

Anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior lesions: A cadaveric study and preliminary report.

OBJECTIVE: This study aims to investigate the anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior (SLAP) lesions in a human cadaveric model. METHODS: In this anatomic study, bilateral shoulder girdles of 12 adult formalin embalmed cadavers were used. All cadavers were male, and the mean age was 63.4±7.3 years. The portal entry point was determined as midway between the anterior and posterior borders of the acromion, approximately 1 cm lateral from the edge of the acromion. After a guidewire was placed in the glenoid cavity at the 12 o'clock position where the SLAP lesion typically occurs, a switching stick was inserted there. Each glenoid was then drilled with a 2.4 mm drill through an arthroscopic cannula. Subsequently, anatomical dissection was executed to assess the relationship of the transmuscular portal with the suprascapular nerve, axillary nerve, supraspinatus tendon, acromion, and biceps tendon. Lastly, the shortest distance between the aforementioned structures with the drill was measured by a sensitive caliper to determine whether there was a penetration of the structures. Differences between the right and left sides were analyzed. RESULTS: The mean distance between the portal and the axillary nerve was 55.5 mm±6.0 mm, and the mean length of the suprascapular nerve was 61.2 mm±7.0 mm. The mean distance between the portal and the supraspinatus tendon was 2.8 mm±1.5 mm. No penetration of the axillary nerve, suprascapular nerve, and supraspinatus tendon was observed in any cadaver. No differences were detected for measured anatomical parameters between the right and left sides (p>0.05). CONCLUSION: Findings from this cadaveric study revealed that the transmuscular portal may allow for a reliable anchor placement without any nerve or tendon penetration during arthroscopic SLAP repair. LEVEL OF EVIDENCE: Level V.

Computed Tomographic Analysis: The Effects of Frontal Recess Morphology and the Presence of Anatomical Variations on Frontal Sinus Pneumatization.

The aim of this study is to describe the morphology of frontal recess area with its anatomical variations and to reveal if frontal recess morphology and the anatomical variations related to that region have effects on the pneumatization of the frontal sinuses. The frontal sinus and recess morphometry of 136 sides of 68 dry skulls were evaluated on multislice high-resolution computed tomography. The relationships between frontal sinus and frontal recess measurements were analyzed by correlation and linear regression analysis. The variables between the groups of anatomical variations were analyzed by Mann-Whitney U test and χ test or Fisher exact test. A positive relationship between the sagittal length of spina nasalis interna and morphometric measurements of frontal sinus was revealed (P <0.05). Agger nasi cells were present in 64.2% of sides, supraorbital ethmoid cells (SOECs) in 19.6%, type 3 frontal cells (FCs) in 18.9%, suprabullar cells in 24.3%, and frontal bulla was noted in 5.4%. Intersinus septal cells were observed in 16.2% of the skulls. There were statistically different increases in the measurements of frontal sinus morphometry in the presences of SOECs and type 3 FCs (P <0.05). The diameter of frontal sinus ostium was decreased in the presences of AN, SOEC, type 3 FC, and supraorbital ethmoid cell statistically (P = 0.049, P = 0.029, P = 0.043, P <0.001 respectively). In conclusion, frontal sinus pneumatization was affected by the spina nasalis interna and the presence of anatomical variations related to frontal recess or ostium region instead of the morphology of that area.

A new method of identifying the posterior inferior nasal nerve: implications for posterior nasal neurectomy.

INTRODUCTION: Posterior nasal neurectomy is an effective way of treating recalcitrant rhinitis. The aim of this study is to describe the anatomic relationship between the posterior inferior nasal nerve (PINN) and the structures that might be important for posterior nasal neurectomy. MATERIALS AND METHODS: An anatomic study was conducted in a university hospital dissection laboratory with 15 formalin-fixed, sagittally cut adult cadaver heads. The distance between PINN and (1) nasal sill, (2) maxillary sinus ostium, (3) posterior fontanel, (4) torus tubarius, and (5) crista ethmoidalis was measured and the location of PINN with respect to the sphenopalatine artery was assessed to define the exact location of PINN. RESULTS: The mean distance between PINN and nasal sill (56.4 mm), maxillary sinus ostium (27 mm), posterior fontanel (12.5 mm), torus tubarius (13 mm), and crista ethmoidalis (8 mm) was determined. PINN was found consistently posterior to the sphenopalatine artery where the inferior turbinate attaches to the lateral nasal wall. CONCLUSION: Instead of finding PINN around the sphenopalatine foramen, PINN can be located more easily posterior to the sphenopalatine artery where the inferior turbinate attaches to the lateral nasal wall without cauterizing the sphenopalatine artery.

Sphenovomerine suture: a useful landmark for locating sphenoid sinus ostium.

AIM: The aim of this study was to determine whether the sphenovomerine suture (SVS) can be used as a landmark to localize the sphenoidal sinus ostium. METHODS: Endoscopic imaging was done on 152 skulls to identify ostium of the sphenoidal sinus, the SVS, and the articulation of sphenoidal process of palatine bone between the body of the sphenoid and the sphenopalatine foramen. The variables were as follows: (1) the distance between the medial border of the ostium and SVS (DSO-SVS); (2) the angle between them (ASO-SVS); (3) the distance between the inferior border of the ostium and the horizontal line (DSO-HL); (4) the distance between intersection point of the SVS-sphenoidal process of the palatine bone and the medial border of sphenopalatine foramen (DSPF-SVS); and (5) the number of sphenopalatine foramen. RESULTS: Of the 152 skulls, 289 sides were included in the study. The mean value for DSO-SVS was 3.15 (1.35) mm, DSO-HL was 5.99 (2.38) mm, DSPF-SVS was 7.07 (1.96) mm, and ASO-SVS was 5.99 (9.73) mm. As DSPF-SVS decreases, DSO-SVS and DSO-HL decrease with statistical significance (Ps = 0.02 and 0.001, respectively). The distribution of the numbers of sphenopalatine foramen was as follows: one 90%, two 9.7%, and four 0.3%. CONCLUSIONS: The horizontal distance between the SVS and the sphenopalatine foramen plays a significant role in identifying the location of sphenoid sinus ostium. As with the other landmarks, the SVS provides an additional benefit in locating the sphenoid sinus ostium for endoscopic sinus surgeons. The incidence of 4 sphenopalatine foramen is 0.3%.

Anatomical evaluation of the superficial veins of the upper extremity as graft donor source in microvascular reconstructions: a cadaveric study.

OBJECTIVE: The aim of study was to investigate the features and resources for vein grafts suitable for upper extremity arteries. METHODS: Sixteen upper extremities of 8 cadavers were investigated. Anatomic localizations, diameters, wall thickness and valve types of the superficial veins of the upper extremity were counted and evaluated. RESULTS: Average diameter of the brachial artery was 3.96 mm, the radial artery 2.54 mm, the ulnar artery 2.12 mm, the proper palmar digital artery 3 0.85 mm, the cephalic vein of the arm 1.81 mm, the basilic vein of the arm 3.20 mm, the cephalic vein of the forearm 2.04 mm, the basilic vein of the forearm 1.35 mm, and the dorsal venous network of the hand 1.27 mm. Three different types of valves were determined. The most frequent valve types were the Type 3 in the cephalic and basilica veins at 86.5% and 90.7%, respectively. CONCLUSION: Data obtained on the superficial veins of the upper extremity may be helpful to surgeons in microsurgical reconstructions.

Conquering the castle: a novel technique for the middle fossa approach in facial decompression.

OBJECTIVE: To describe 2 subapproaches of the middle fossa approach: the transillumination method and transection of lines using the foramen spinosum, greater superficial petrosal nerve, and trigeminal impression to locate the malleus head for safe identification and decompression of the geniculate ganglion and facial nerve. STUDY DESIGN: Cadaver study. SETTING: A tertiary university hospital anatomy laboratory. SUBJECTS AND METHODS: The present study was conducted using 7 formalin-fixed cadaver heads (14 sides). A 0° endoscope was introduced into the external ear canal toward the posterosuperior quadrant of the tympanic membrane, after which transillumination was used to locate the malleus head. The brightest point indicated the convergence of the greater superficial petrosal nerve and a line drawn along the superior semicircular canal. An additional line was drawn parallel to the petrous ridge from the foramen spinosum and along the pathway of the greater superficial petrosal nerve. A third line connected the trigeminal impression to the zygomatic root. The area posterior to the intersection of these 2 lines separately with the third line was considered the zone of location of the malleus head. Among 17 patients undergoing surgery for facial paralysis between 1993 and 2011, transillumination was used in 6 patients to identify the malleus head to locate the geniculate ganglion. RESULTS: These techniques were proven to be reliable in locating the malleus head to find the geniculate ganglion in 14 dissected cadaveric temporal bones. CONCLUSION: Two methods of locating the malleus head for facial decompression were defined.

Anatomical variations of iliolumbar artery and its relation with surgical landmarks.

OBJECTIVES: The aim of this study was to reveal the variations of origin of iliolumbar artery, and its relations with the surrounding surgically important anatomical structures. METHODS: The origin, diameter, and tract of iliolumbar artery were determined bilaterally in 21 formalin-fixed adult male cadavers (21 right and 21 left arteries) in the Laboratory of Department of Anatomy. RESULTS: Iliolumbar artery was originating from common iliac artery in 4.8% (2 arteries), internal iliac artery in 71.4% (30 arteries), posterior trunk of internal iliac artery in 19% (8 arteries), and as two different arteries from internal iliac artery in 4.8% (2 arteries) of the cases. The mean diameter of the iliolumbar artery was 3.7 mm. CONCLUSION: The anatomical properties of iliolumbar artery and its relation with anatomical landmarks, which were presented here, would be helpful in decreasing iatrogenic trauma to iliolumbar artery during surgery.

The effects of prenatal and neonatal exposure to electromagnetic fields on infant rat myocardium.

INTRODUCTION: Electromagnetic fields (EMF) have adverse effects as a result of widespread use of electromagnetic energy on biological systems. The aim of this study was to investigate the effects of prenatal exposure to EMF on rat myocardium by biochemical and histopathological evaluations. MATERIAL AND METHODS: In this study, 10 pregnant Wistar rats were used. Half of the pregnant rats were exposed to EMF of 3 mT, and the other half to sham conditions during gestation. After parturition, rat pups in the 5 EMF-exposed litters from birth until postnatal day 20 were exposed to EMF of 3 mT for 4 h/day (EMF-exposed group, n = 30). Rat pups in sham litters from birth until postnatal day 20 were exposed to sham conditions (sham group, n= 20). RESULTS: In the EMF-exposed group, lipid peroxidation levels significantly increased compared to sham. Superoxide dismutase activities decreased significantly in the EMF-exposed group compared to sham. TUNEL staining showed that the number of TUNEL-positive cells increased significantly in EMF-exposed rats compared with sham. Under electron microscopy, there were mitochondrial degeneration, reduction in myofibrils, dilated sarcoplasmic reticulum and perinuclear vacuolization in EMF-exposed rats. CONCLUSIONS: In conclusion, the results show that prenatal exposure to EMF causes oxidative stress, apoptosis and morphological pathology in myocardium of rat pups. The results of our study indicate a probable role of free radicals in the adverse effects of prenatal exposure to EMF. Further studies are needed to demonstrate whether the EMF exposure can induce adverse effects on the myocardium.

The human sacrum and safe approaches for screw placement.

The human sacrum is the target of lumbosacral instrumentation and decompression procedures. Such surgical interventions require detailed knowledge of the anatomy of the human sacrum. The aim of this study was to measure surgically relevant parameters. Several factors, including the one-piece composition of the sacrum, the angles of the sacral pedicles and the anteroposterior diameter of the sacral vertebral bodies distinguish the sacrum from other parts of spine. Thirty-two measurements of shape, angles and distances between parts were taken of the sacra of 100 adult West Anatolian people using a Vernier caliper accurate to 0.1 mm and goniometer. According to this morphometric study, when measured from the sagittal, the S1 facet angle was measured as 35.71 degrees +/-9.59 and 34.70 degrees +/-9.66, the sacral pedicle anteromedial screw trajectory angle was 35.65 degrees +/-4.73 and 31.95 degrees +/-3.95 and the anterolaterally oriented sacral wing screw trajectory angle was 32.65 degrees +/-3.51 and 29.10 degrees +/-3.14, on the right and left sides, respectively. The distance of the midline oriented S1 pedicle screw was 51.12 mm and 51.26 mm on the right and left side, respectively. The distance for sacral wing oriented screw placement was 50.13 mm and 50.46 mm on the right and left side, respectively. The anteroposterior and transverse diameter of the sacral spinal canal were 21.81 mm and 31.31 mm, respectively. Thus, this study describes anatomical specifications of the sacrum. These defined morphometric details should be taken into consideration during surgical procedures. This study also describes anatomical landmarks which will allow injury of the sacrum during surgery to be avoided.

Effectiveness of royal jelly on tympanic membrane perforations: an experimental study.

OBJECTIVE: The aim of this study was to evaluate the comparison of the efficacy of royal jelly in a guinea pig tympanic membrane perforation model with untreated and control groups. STUDY DESIGN: Prospective study using 16 adult guinea pigs. METHODS: Each animal underwent subtotal removal of the tympanic membrane in one ear. Animals were divided into two groups of eight animals each. Group A was treated with topical royal jelly, and group B was treated with saline. All opposite right ears were used as the control group. Examination was done by otoendoscopy on days 10, 12, and 14. The healing process was observed under the microscope and photographed for 3 months. RESULTS: There was no significant difference between group A and group B in the incidence of perforation closure. However, after 3 months, the mean thickness of the tympanic membranes was 0.11, 0.07, and 0.08 mm, respectively, in group A, group B, and the control. These results showed a statistically significant difference. Histologically, the tympanic membranes of group A showed marked fibroblastic orientation and well-organized connective tissue. Application of royal jelly improved the success rate of closure, as shown in the present study. CONCLUSIONS: This is the first study to investigate the effectiveness of royal jelly in enhancing healing in tympanic membrane perforations. Our study suggests that royal jelly is effective in increasing healing of tympanic membrane perforations in guinea pigs.

Neurovascular risks of sacral screws with bicortical purchase: an anatomical study.

The aim of this cadaver study is to define the anatomic structures on anterior sacrum, which are under the risk of injury during bicortical screw application to the S1 and S2 pedicles. Thirty formaldehyde-preserved human male cadavers were studied. Posterior midline incision was performed, and soft tissues and muscles were dissected from the posterior part of the lumbosacral region. A 6 mm pedicle screw was inserted between the superior facet of S1 and the S1 foramen. The entry point of the S2 pedicle screw was located between S1 and S2 foramina. S1 and S2 screws were placed on both right and the left sides of all cadavers. Then, all cadavers were turned into supine position. All abdominal and pelvic organs were moved away and carefully observed for any injury. The tips of the sacral screws were marked and the relations with the anatomic structures were defined. The position of the sacral screws relative to the middle and lateral sacral arteries and veins, and the sacral sympathetic trunk were measured. There was no injury to the visceral organs. In four cases, S1 screw tip was in direct contact with middle sacral artery. In two cases, S1 screw tip was in direct contact with middle sacral vein. It was observed that the S1 screw tips were in close proximity to sacral sympathetic trunk on both right and the left sides. The tip of the S2 screw was in contact with middle sacral artery on the left side only in one case. It is found that the tip of the S2 screw was closely located with the middle sacral vein in two cases. The tip of the S2 pedicle screw was in contact with the sacral sympathetic trunk in eight cases on the right side and seven cases on the left side. Lateral sacral vein was also observed to be disturbed by the S1 and S2 screws. As a conclusion, anterior cortical penetration during sacral screw insertion carries a risk of neurovascular injury. The risk of sacral sympathetic trunk and minor vascular structures together with the major neurovascular structures and viscera should be kept in mind.

Thoracic duct variations may complicate the anterior spine procedures.

The aim of this study is to localize and document the anatomic features of the thoracic duct and its tributaries with special emphasis on the spinal surgery point of view. The thoracic ducts were dissected from nine formaldehyde-preserved male cadavers. The drainage patterns, diameter of the thoracic duct in upper, middle and lower thoracic segments, localization of main tributaries and morphologic features of cisterna chyli were determined. The thoracic duct was detected in all cadavers. The main tributaries were concentrated at upper thoracic (between third and fifth thoracic vertebrae) and lower thoracic segments (below the level of ninth thoracic vertebra) at the right side. However, the main lymphatic tributaries were drained into the thoracic duct only in the lower thoracic area (below the level of the tenth thoracic vertebra) at the left side. Two major anatomic variations were detected in the thoracic duct. In the first case, there were two different lymphatic drainage systems. In the second case, the thoracic duct was found as bifid at two different levels. In formaldehyde preservation, the dimensions of the soft tissues may change. For that reason, the dimensions were not discussed and they may not be a guide in surgery. Additionally, our study group is quite small. Larger series may be needed to define the anatomic variations. As a conclusion, anatomic variations of the thoracic duct are numerous and must be considered to avoid complications when doing surgery.

Surgical anatomy of the internal branch of the superior laryngeal nerve.

The internal branch of the superior laryngeal nerve (ibSLN) may be injured during anterior approaches to the cervical spine, resulting in loss of laryngeal cough reflex, and, in turn, the risk of aspiration pneumonia. Such a risk dictates the knowledge regarding anatomical details of this nerve. In this study, 24 ibSLN of 12 formaldehyde fixed adult male cadavers were used. Linear and angular parameters were measured using a Vernier caliper, with a sensitivity of 0.1 mm, and a 1 degrees goniometer. The diameter and the length of the ibSLN were measured as 2.1+/-0.2 mm and 57.2+/-7.7 mm, respectively. The ibSLN originates from the vagus nerve at the C1 level in 5 cases (20.83%), at the C2 level in 14 cases (58.34%), and at the C2-3 intervertebral disc level in 5 cases (20.83%) of the specimens. The distance between the origin of ibSLN and the bifurcation of carotid artery was 35.2+/-12.9 mm. The distance between the ibSLN and midline was 24.2+/-3.3 mm, 20.2+/-3.6 mm, and 15.9+/-4.3 mm at the level of C2-3, C3-4, and at the C4-5 intervertebral disc level, respectively. The angles of ibSLN were mean 19.6+/-2.6 degrees medially with sagittal plane, and 23.6+/-2.6 degrees anteriorly with coronal plane. At the area between the thyroid cartilage and the hyoid bone the ibSLN is the only nerve which traverses lateral to medial. It is accompanied by the superior laryngeal artery, a branch of the superior thyroid artery. The ibSLN is under the risk of injury as a result of cutting or compression of the blades of the retractor at this level. The morphometric data regarding the ibSLN, information regarding the distances between the nerve, and the other consistent structures may help us identify this nerve, and to avoid the nerve injury.

The V2 segment of the vertebral artery in anterior and anterolateral cervical spinal surgery: a cadaver angiographic study.

OBJECTIVE: The second segment of the vertebral artery is under the risk of injury during anterior and anterolateral cervical spine procedures. To avoid such a risk, one needs to be familiar with the regional anatomy. The aim of this study was to measure the distance between the vertebral artery and the uncinate process, midline, and the medial side of the longus colli muscle using vertebral artery angiograms at the level of C6, C5, C4, and C3 vertebrae. MATERIALS AND METHODS: In 12 human cadavers, the vertebral arteries were first irrigated with water. Then the arteries were filled with silicon and barium, and finally their angiographic images were obtained. RESULTS: The transverse diameter of the vertebral artery was measured at C6, C5, C4, C3, and C2 level. The values on the left were bigger than the values on the right (p>0.05). The distance between the vertebral artery and the midline decreased from C6 (17.2+/-5.6mm on the right, 17.2+/-2.3mm on the left) to C3 (15.8+/-5.3mm on the right, 13.8+/-2.1mm on the left) (p>0.05). The distance between the apex of the uncinate process and the medial side of the vertebral artery was found to be longer at C4 (2.7+/-1.0 mm on the right, 2.2+/-1.0mm on the left) and C5 (2.5+/-1.1mm on the right, 2.5+/-1.0mm on the left) vertebra levels on the right side (p=0.339 at C4, p=0.862 at C5). The distance between the medial side of the longus colli muscle and the medial side of the vertebral artery was measured as 9.7+/-2.7 mm (9.5+/-2.9 mm on the right, 9.8+/-2.6mm on the left) at C6 level, 9.2+/-2.6mm (8.6+/-2.4mm on the right, 9.8+/-3.1mm on the left) at C5, 9.4+/-1.9 mm (9.2+/-2.1mm on the right, 9.5+/-2.0mm on the left) at C4, and 10.4+/-2.7 mm (10.5+/-3.0mm on the right, 10.1+/-2.6mm on the left) at C3 vertebra level. No significant difference was found between the right and the left (p>0.05). The angle between the vertebral artery and the midline was measured as 4.0+/-1.9 degrees on the right and 2.2+/-1.4 degrees on the left side (p=0.030). CONCLUSION: It was considered that the values obtained could be useful in anterolateral and anterior cervical approaches in terms of evaluating the position of the vertebral artery and its relation to vertebral structures. It is also concluded that the risk of injury in upper subaxial cervical spine is higher than in the lower part of the subaxial cervical spine.

Iliolumbar veins have a high frequency of variations.

The spectrum of individual anatomic variations of the vascular structures are broad, however, the exact incidence of variations of the lumbosacral vein is obscure. In the current study, 38 iliolumbar veins were dissected from 19 formaldehyde-preserved male cadavers. The drainage pattern of the iliolumbar vein was determined. The diameter and the length of the iliolumbar vein were measured, and the relationships of the iliolumbar vein with the lumbosacral trunk, obturator nerve, and iliolumbar artery were ascertained. Means and standard deviations were used as descriptive measures to define variations among the cases. The iliolumbar vein or veins were detected in both sides of all 19 cadavers. Five drainage patterns were seen between the iliolumbar vein and the lumbosacral major veins. In only five cadavers, symmetric drainage patterns were seen on the left and the right sides. In our study, two drainage patterns were seen that were not previously reported. Anatomic variations of the iliolumbar vein are numerous and should be considered to avoid complications when doing surgery.

Arterial anatomy of the lower lip: a cadaveric study.

The aim of the study was to investigate the arterial anatomy of the lower lip. The location, course, length, and diameter of the inferior labial artery and the sublabial artery were revealed by bilateral meticulous anatomic dissections in 14 adult male preserved cadaver heads. Another cadaver head was used for silicone rubber injection to fill the regional arterial tree. The inferior labial artery was the main artery of the lower lip and in all cases branched off the facial artery. The mean length of the inferior labial artery was found to be 52.3 mm (range, 16 to 98 mm). The mean distance of the origin of the inferior labial artery from the labial commissura was 23.9 mm. The mean external diameter of the inferior labial artery at the origin was 1.2 mm. The sublabial artery was present in 10 (71 percent) of the cadavers. Mean measurements of this artery were 1 mm for diameter, 23.4 mm for length, and 27.6 mm for distance from the labial commissura. The sublabial artery may originate from the facial artery or the inferior labial artery. This study found that this region does not have a constant arterial distribution, the inferior labial artery and the sublabial artery (if it exists) can be in different locations unilaterally or bilaterally, and the diameter and the length may vary.