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Object. The C-2 pedicle plays an important role regarding screw purchase for spinal fixation. The aim of this study was to measure the C-2 pedicle—related linear and angular parameters. Methods. Seven parameters in 160 C-2 pedicles (80 dry vertebrae) were measured using a Vernier caliper (accurate to 0.1 mm) and goniometer. The Student t-test was used to determine statistical significance. The authors found that the C-2 isthmus (pars interarticularis) and the C-2 pedicle are distinct structures. The C-2 isthmus covers the pedicle. The isthmus is present between the superior and inferior articular processes, and the pedicle is the structure beneath the C-2 isthmus. It connects the lateral mass—inferior articular process to the body of the axis. The heights of the right and the left C-2 pediculoisthmic components (PICs) were 10.3 ± 1.6 and 9.9 ± 1.5 mm, respectively. The posterior part of the superior aspect of the PIC was wider than the anterior portion. The widths of the posterosuperior aspect of the PIC were 11.1 ± 2 and 11 ± 1.7 mm on the right and left sides, whereas the widths of the anterosuperior aspect of the PIC were 7.9 ± 1.7 and 8.5 ± 1.6 mm, respectively. The inferior widths of this component were 6.0 ± 1.5 and 5.5 ± 1.3 mm on the right and left side, respectively. The lengths of the component were 28.8 ± 2.9 mm on the right and 28.8 ± 3.4 mm on the left side. The PIC exhibits a lateral-to-medial and an inferior-to-superior angle. Its axial angles were 28.4 ± 2.5 and 28.6 ± 2.2° on the right and left sides, respectively; its sagittal angles were 18.8 ± 2.1 and 18.8 ± 1.7°, respectively. Conclusions. The C-2 pedicle can be seen in the inferior aspect of the vertebra, and it connects posterior vertebral elements (that is, the lateral mass and inferior articular process) to the axial body. The isthmus drapes the pedicle. The authors suggest that this be termed “the pediculoisthmic component.”

Impingement by the distal fascicle of the anterior inferior tibiofibular ligament (AITFL) is a relatively new entity among the known causes of anterolateral impingement syndromes of the ankle. This study investigated the anatomy of the anterior inferior tibiofibular ligament and its possible role in talar impingement in 47 ankles of 27 cadavers. The length, width, insertion point to the fibula and the interactions with talus were noted, as was the relationship of the fascicle and talus during different ankle movements before and after incision of the lateral ligaments. A distal fascicle of the AITFL was found in 39 of the 47 ankles (83%) and appeared as a single-complete ligament in the remaining 8 ankles (17%). The fascicle averaged 16.1 +/- 2.94 mm in length (range 10-21) and 4.2 +/- 1.00 mm in width (range, 3-7). The insertion point of the fascicle on the fibula averaged 10.3 +/- 2.27 mm (5-13) distal to the joint level. Contact between the ligament and the lateral dome of the talus was observed in 42 specimens (89.3%). Bending of the fascicle was observed in 8 of these 42 ankles with forced dorsiflexion. These 8 specimens were significantly wider and longer than the specimens without bending of the fascicle. Incision of the anterior talofibular ligament led to bending in dorsiflexion in additional 11 ankles. The total 19 fascicles with bending after incision of the anterior talofibular ligament were significantly longer and inserted more distally than the remaining 20 fascisles without bending. Manual traction simulating distraction during arthroscopic procedures relieved the contact. These findings show that the presence of the distal fascicle of the AITFL and its contact with the talus is a normal finding. However, it may become pathological due to anatomical variations and/or instability of the ankle resulting from torn lateral ligaments. When observed during an ankle arthroscopy, the surgeon should look for the criteria described in the present study to decide whether it is pathological and needs to be resected.

The aim of this study was to compare the finger length ratio (2D:4D), hair whorl direction, and hand, foot, and eye dominance in autistic and healthy individuals, and to investigate the phenotypic characteristics of autism.The study included 37 males diagnosed with autistic disorder and 121 healthy males, all aged 4-18 years. The length of the index and ring fingers of both hands--from the proximal bend of the metacarpophalangeal joint to the fingertips--was measured with digital calipers and the index-ring finger (2D:4D) ratio was determined. The distance between hair whorls, their perpendicular distance from the mid-sagittal line, and their direction of rotation were calculated in the autism and control groups. Hand, foot, and eye dominance were determined in both groups. The findings were evaluated using SPSS v.15.0.The autism group had a greater number of hair whorls than the control group. The distance between hair whorls and the mid-sagittal line was longer in those with left hand and left eye dominance. A significant difference in the 2D:4D ratio of the right and left hands between the 2 groups was not observed.The autism group had more hair whorls than the control group and the hair whorls in the autistic individuals with left hand and left eye dominance were located further from the mid-saggital line. We think that these novel findings might contribute to the determination of the phenotypic features specific to autism.

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 SI 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 SI 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 21.84 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. (C) 2008 Elsevier Ltd. All rights reserved.

The location and incidence of the zygomaticofacial foramen (ZFF) was studied in 80 dry skulls (160 sides) of unsexed adult skulls of West Anatolian people. The average distances from the ZFF to the frontozygomatic suture, to the zygomaticomaxillary suture, and to the inferior orbital rim were found to be 26.2 +/- 3.2 mm, 18.6 +/- 3.14 mm, and 5.94 +/- 1.43 mm, respectively. The zygomas were evaluated for the number of foramina on their facial aspects. There was none in 25 (15.6%), one in 71 (44,4%), two in 45 (28.1%), three in 10 (6.3%), four in seven (4.4%), and five in two (1.3%) sides. The ZFF was also studied for its distribution around the zygoma by dividing the surface into four anatomical areas. There was no statistical difference between the morphometrical results on both sides. Data regarding the location and variation in the number of the ZFF is important in avoiding zygomatic nerve and vessel injury during surgery, but by virtue of the great variability found, ZFF is an unreliable landmark for maxillofacial surgery. Clin. Anat. 22:559-562, 2009. (C) Wiely-Liss, Inc.

The maxilla is the key structure on facial formation and stability. The knowledge about maxillary thickness and dimensions is crucial during facial reconstruction including this bone. In this study, anthropometric measurements of anterior wall of the maxilla on the dry human skulls were aimed. Sixty maxillae of 30 adult dry skulls of West Anatolian people were evaluated. Four vertical lines were drawn between the piriform aperture and lateral border of the bone and six horizontal lines between the infra-orbital margin and the inferior border of the piriform aperture. After establishing the lines, maxillary thicknesses on the intersection points of the vertical and horizontal lines and the lengths of the vertical lines from the infra-orbital margin to alveolar arch were measured by using a fine caliper. It was found that the thickest point of the anterior wall of the maxillae is on the lateral of the infra-orbital margin (5.17 +/- 2.27 mm), and thinnest one is on the inferior of the infra-orbital foramen (0.92 +/- 1.06 mm). The length of the vertical line tangent to piriform aperture (47.66 +/- 3.61 mm) is the longest. The corresponding data of the left and right maxillae were compared by Student's t test. There was no significant difference between both sides. After collecting the data, a thickness map of anterior wall of the maxilla was drawn. This data may be helpful in clinic during osteotomies, bone reconstructions, screw, or other reconstruction apparatus applications on the maxilla.

Although limited carpal fusions used in the treatment of Kienböck's disease are thought to act by decreasing the loads on the lunate, biomechanical studies show that capitohamate fusion acts oppositely to what is expected. This experimental study was designed to resolve this paradox.In a biomechanical cadaveric study, load transmissions at the radioulnacarpal joint were investigated under 140 and 210 newtons of load with three wrist postures, namely, neutral, ulnar and radial deviations, in five intact wrists and after scaphotrapeziotrapezoid, capitohamate, and scaphocapitate fusions.Under 140 newtons of load, the loads imposed to the lunate decreased following scaphotrapeziotrapezoid and scaphocapitate fusions, but increased after capitohamate fusion. However, when the load was increased to 210 newtons, there were no differences between intact wrists and limited carpal fusions in respect to the loads exerted on the lunate. In all the situations, the lunate was subjected to a significantly greater load in ulnar deviation.These results suggest that limited carpal fusions do not alter load transmission characteristics of the wrist joint under 210 newtons of load. The etiology of the Kienböck's disease seems to be related to an overload in ulnar deviation and the beneficial effect of limited carpal fusions seems to be associated with restricted ulnar deviation of the wrist rather than load transmission characteristics.

Objective: The human occipital condyle is the unique bony structure connecting the cranium and the vertebral column. The progress in neuroimaging techniques has increased interest for aggressive craniovertebral surgery. Such surgery requires the knowledge regarding anatomical aspects of the craniovertebral junction. The aim of the present study is to analyze the occipital condyle morphometrically. Material and methods: 404 occipital condyles of 202 dry skulls were used for this study. Twenty-seven parameters were measured, including length, width and height of occipital condyle, the distances between the occipital condyle and hypoglossal canal, as well as some important condyle-related angles. Results: The length, width and the height of the occipital condyle were found to be 23.4, 10.6, and 9.2 mm, respectively. The anterior and posterior intercondylar distances are 21.0 and 41.6 mm, respectively. Sagittal intercondylar angle was 59.3 ◦ . The intracranial orifice of the hypoglossal canal was found in the junction of the second and third quarter on the condyle in more than 55% of specimens. The shape of occipital condyles was classified into eight types as followings—type 1: oval-like condyle; type 2: kidney-like condyle; type 3: S-like condyle; type 4: eight-like condyle; type 5: triangle condyle; type 6: ring-like condyle; type 7: two-portioned condyle and type 8: deformed condyle. The most common type was type 1 (50%), whereas the most unusual type was type 7 (0.8%). Conclusion: It is concluded that the occipital condyle may present various shapes, length, width, and orientation, requiring a careful radiological analysis before craniovertebral junction surgery. © 2004 Elsevier B.V. All rights reserved.

Craniovertebral junction surgery requires knowledge regarding the anatomy of this region, particularly the C1 vertebra. Both C1 laminectomy and C1-2 instrumentation necessitate preoperative information about bony landmarks and the vertebral artery. This study compares the results obtained from anatomic and computed tomographic measurements of C1 bony landmarks. 31 C1 cervical vertebrae were measured; the C1 AP diameter, and C1 transverse diameter, the facet diameter, the distance between the anterior tubercle and the anterior aspect of the C1 lateral mass on a lateral view, the distance between the midline and the vertebral artery groove on the outer cortex of the posterior arch of C1 anatomically and computed tomographically. Anatomic measurements were performed by an anatomist using a Vernier caliper accurate to 0.1 mm, whereas the computed tomographic measurements were performed by a radiologist on bone window computed tomography (CT). The mean values and the differences between two measurement modalities were analysed using a paired t-test. There was no statistical difference between the results obtained by anatomical and radiological measurements for six parameters. There was, however, a statistically significant difference between two modalities regarding the distance between the midline and vertebral artery groove on the outer cortex of posterior arch of C1, while slightly different, the difference is within 1 mm and, therefore, not clinically significant. It is concluded that CT reflects most anatomical details of bony landmarks of C1. (C) 2003 Elsevier Science B.V. All rights reserved.