Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Embalming”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources
PubMed1998

Analytical evaluation of complex anterior approaches to the cranial base: an anatomic study.

OBJECTIVE: The purpose of the present study was to evaluate the anatomic areas of the cranial base exposed by different complex anterior approaches. METHODS: Using 20 embalmed cadaveric heads, we executed five different anterior approaches, i.e., Le Fort 1 approach with splitting or down-fracturing of the hard palate, extended maxillectomy, median mandibulotomy with glossotomy, and mandibular swing transcervical approach. Each approach was performed a minimum of three times. The areas of the intra- and extracranial cranial base exposed by each approach were analytically examined by using a numerical grading system to assess the exposure of major anatomic and neurovascular structures. RESULTS: Good exposure of the midline compartment of the cranial base was provided by the median mandibulotomy with glossotomy and by the Le Fort 1 approach with splitting of the hard palate, whereas the mandibular swing transcervical and extended maxillectomy approaches provided good exposure of the lateral compartment of the cranial base. CONCLUSION: Use of the numerical grading system allowed quantification of the exposure afforded by each approach, with respect to the different compartments (midline and lateral) of the intra- and extracranial cranial base, highlighting the differences among the approaches examined.

Cadaver↗
PubMed2000

The pretemporal transcavernous approach to the interpeduncular and prepontine cisterns: microsurgical anatomy and technique application.

OBJECTIVE: To illustrate in a stepwise fashion the microsurgical anatomy of the transcavernous approach to the interpeduncular and prepontine cisterns and to discuss our initial results with 15 basilar tip aneurysms managed through that approach. METHODS: Using 10 embalmed cadaveric heads perfused with colored silicon, we performed bilateral stepwise dissections of the transcavernous approach via an orbitozygomatic pretemporal craniotomy. Measurements of the exposure of the basilar artery obtained along the dorsum sellae and upper clivus were taken. Our clinical data were derived from a series of 15 patients with large basilar tip aneurysms treated surgically via the transcavernous approach between 1997 and 1999. Indications for surgery were based on the size of the aneurysm (all were large) and its position in relation to the dorsum sellae (eight were more than 5 mm below the level of the dorsum sellae). RESULTS: Good exposure of the neurovascular structures of the interpeduncular and prepontine cisterns (namely, the basilar artery) was obtained in all cases as compared with other well-established approaches to the area. All patients in our surgical series did well except that all incurred an expected third nerve palsy, caused by surgical manipulation, which resolved over the course of 2 weeks to 3 months. CONCLUSION: Although technically difficult, the transcavernous approach provides better exposure of the interpeduncular and prepontine cisterns relative to that afforded by other, more conventional approaches. The satisfactory results obtained in our preliminary series of patients greatly support the use of this approach for complex basilar tip aneurysms.

Angiography, Digital Subtraction↗
PubMed1987

Anatomy of the subcutaneous tissue of the trunk and lower extremity.

Dissections on 8 fresh and 10 embalmed cadavers were used to determine the anatomy of the subcutaneous adipose tissue in the trunk and extremities. These dissections, along with CT scans, confirmed Gray's original description of the subcutaneous tissue consisting of a superficial and deep adipose layer. The superficial adipose layer is contained within organized, compact fascial septa. The deep adipose layer demonstrated regional variations with respect to its fascial framework, but was contained within a relatively loose, less organized, and more widely spaced fascial septa. We observed that the adipose layers are partitioned by a discrete subcutaneous fascia which fuses with the underlying muscle fascia at particular anatomic locations. The deep layer is thus contained by the subcutaneous fascia above and the muscle fascia below to form what we termed the deep adipose compartments. The deep adipose compartments contributed significantly to overall adipose thickness, are bilateral, and are found in the abdomen and paralumbar and gluteal-thigh regions.

Abdomen↗
PubMed1996

A reappraisal of axial and nonaxial lower leg fascial flaps: an anatomic study in human cadavers.

The aim of this study was to determine the sources of blood supply to the deep fascia of the lower leg and therefore to identify potential new sites where axial and nonaxial flaps might be raised. The deep fascia was harvested from 18 embalmed cadaver lower legs. The blood supply to the deep fascia was examined with the aid of a dissecting microscope. Four clinically important sources of supply to the deep fascia were identified. These were (1) axial and nonaxial fasciocutaneous perforators, (2) nonaxial musculocutaneous perforators, (3) axial cutaneous branches of the sural arteries, and (4) an axial fascial branch from the saphenous artery (present in 75 percent of the dissections). This study has highlighted the potential for utilizing not only the fasciocutaneous system and sural system of vessels but also the fascial branch of the saphenous artery in the design of lower leg axial fascial flaps. Nonaxial fascial island flaps may be raised utilizing not only the fasciocutaneous system of vessels but also the musculocutaneous system of vessels.

Arteries↗
PubMed1998

The anatomic basis for the innervated mylohyoid/digastric flap in facial reanimation.

This paper describes the anatomy of the neurovascular supply to the mylohyoid and digastric muscle and its potential use for a regional transposition to rehabilitate the paralyzed face and soft-tissue coverage in the head and neck area. The anatomy and the arc of rotation of this flap were determined in ten embalmed cadavers. To further demonstrate the vascular supply, the common carotid was injected with silicone in four additional fresh cadavers. In all specimens, the submental artery and the mylohyoid nerve were the sole contributors to the neurovascular supply of the mylohyoid and digastric muscle. The arc of rotation was an average of 5 cm (range 4 to 6.5 cm), which allowed the flap to be positioned appropriately between the zygomatic arch and the modiolus. From this anatomic study, the mylohyoid/digastric flap has a long enough neurovascular pedicle to be useful in facial reanimation and soft-tissue coverage in the head and neck area.

Anastomosis, Surgical↗
PubMed2001

Anatomic variability of the ilioinguinal and genitofemoral nerve: implications for the treatment of groin pain.

The differential diagnosis of groin pain must consider problems of the ilioinguinal and/or genitofemoral nerve. These nerves may become injured during hernia surgery or lower quadrant surgical procedures. To treat injury to these nerves, it is critical to understand their anatomic variability. In the present study the pattern of cutaneous nerve branches in the inguinal region was investigated through dissection in 64 halves of 32 human embalmed anatomic specimens. In contrast to usual textual descriptions, four different types of cutaneous branching patterns are identified: type A, with a dominance of genitofemoral nerve in the scrotal/labial and the ventromedial thigh region. In type A, the ilioinguinal nerve gives no sensory contribution to these regions (43.7 percent). In type B, with a dominance of ilioinguinal nerve, the genitofemoral nerve shares a branch with the ilioinguinal and gives motor fibers to cremaster muscle in the inguinal canal, but has no sensory branch to the groin (28.1 percent). In type C, with a dominance of genitofemoral nerve, the ilioinguinal nerve has sensory branches to the mons pubis and inguinal crease together with an anteroproximal part of the root of the penis or labia majora. The nerve was found to share a branch with the iliohypogastric nerve (20.3 percent). In type D, cutaneous branches emerge from both the ilioinguinal and the genitofemoral nerves. Additionally, the ilioinguinal nerve innervates the mons pubis and inguinal crease together with a very anteroproximal part of the root of the penis or labia majora (7.8 percent). The described patterns of innervation were bilaterally symmetric in 40.6 percent of the cadavers. The anatomic variability of both nerves has implications for all surgeons operating in the groin region and for those caring for the patient with groin pain.

Abdomen↗
PubMed2002

The temporalis: blood supply and innervation.

Numerous reports have described the use of the temporalis muscle as a pedicled flap in reconstructive surgery. A detailed knowledge of the supplying vessels and nerves is necessary for functionally successful muscle transposition. However, controversial anatomic descriptions exist. In this study, 60 human cadavers were investigated to identify the arteries and nerves supplying the temporalis. Forty-three cadavers were dissected after embalming with 10% phenol/formaldehyde. An additional 10 cadavers were examined after injecting latex/barium sulfate (ratio, 1:1) to show the parts of the temporalis supplied by each artery using radiography. The innervating motor branches of the trigeminal nerve were identified by the Karnovsky technique in seven fresh cadavers. In all specimens, three arteries supplying the temporalis were identified: the anterior deep temporal artery (anterior part, 30 percent muscle mass), the posterior deep temporal artery (central part, 51 percent muscle mass), and the medial temporal artery (occipital and in 25 percent upper part, 19 percent muscle mass). Motor branches of the trigeminal nerve innervated the temporalis: the deep temporal nerves of the mandibular nerve (98 percent, central part), branches of the buccal nerve (95 percent, anterior part), and branches of the masseteric nerve (69 percent, posterior part). A remarkable variation of innervating nerve branches, and in 12 percent peripheral anastomoses between the motor nerve branches, were observed. The various numbers of innervating nerve branches demonstrate the difficulty of creating innervated or selectively denervated pedicled muscle flaps for reinnervation. Nevertheless, at least two different pedicled flaps using the anterior or central part of the temporalis can be selectively used for reconstructive surgery.

Arteries↗
PubMed1986

Are there compartment syndromes in some patients with idiopathic back pain?

Palpable rigidity of the epaxial (paraspinal) muscles, lordotic flattening, and spinal flexion accompanying back pain generally are ascribed to epaxial muscle spasm. However, palpable rigidity without muscle spasm occurs in compartment syndromes and epaxial muscle contractions extend the spine, increasing lordosis. Epaxial compartment syndromes are proposed as a possible cause of palpable rigidity, lordotic flattening, and spinal flexion accompanying idiopathic back pain. This article demonstrates the following: existence of an epaxial compartment by latex and dye injections; simulation of epaxial compartment syndromes in unembalmed cadavers by saline injections; and a "Bourdon tube effect" producing spinal flexion with lordotic flattening during epaxial compartment syndrome simulation in embalmed cadavers. In addition, resting and exercising epaxial compartment pressures were measured in 18 normal volunteers with a slit catheter.

Aged↗
PubMed1988

A three-dimensional digitization method to measure trunk muscle lines of action.

A method is presented to obtain lines of action of nine major trunk muscles acting on the lumbar spine. The muscles are modeled as one or several linear or curvilinear lines of action obtained by digitizing the origins and insertions of main bundles of muscles. For curvilinear lines of action, points were also digitized along the length of the bundles, and a curve-fitting method was used. Lines of action are displayed graphically for one embalmed cadaver. Tabulated data for unit force vectors and unit moment vectors about the L3-L4 and L4-L5 discs are also presented.

Adult↗
PubMed1991

Orientation and moment arms of some trunk muscles.

The orientations and moment arms of nine trunk muscles: latissimus dorsi, iliocostalis, longissimus dorsi, obliquii, rectus and transversalis abdominis, quadratus lumborum, and iliopsoas were obtained on embalmed specimens. Each muscle was considered as one or several, linear or curvilinear, lines of action. Origins, insertions, and points along the length of main bundles were digitized for each muscle using a three-dimensional digitizer. The results obtained from seven male specimens are presented and will permit more refined biomechanical models.

Abdominal Muscles↗
PubMed1994

Morphology of C5 ventral nerve rootlets as part of dissociated motor loss of deltoid muscle.

STUDY DESIGN: This study analyzed anatomic characteristics of cervical ventral rootlets. After total vertebrectomy, detailed morphology of the ventral rootlets was studied from the anterior. SUMMARY OF BACKGROUND DATA: The clinical study showed the predominance of ventral root lesion. There are few studies concerning the morphologic pathogenesis of cervical amyotrophy and detailed cervical ventral rootlet anatomy. METHODS: Thirty-six embalmed adult human cadavers were studied. The measurements for the ventral rootlets of C5 to C8 were made as follows: 1) angle between the rootlet and spinal cord, 2) longitudinal width of the ventral rootlet origin, and 3) length of the ventral rootlets. RESULTS: The C5 ventral rootlets were shorter and issued more obtusely from the cervical spinal cord than lower rootlets. The spinal cord segment of the deltoid muscle, indicated by the longitudinal widths of the C5 and C6 ventral rootlet exits from the spinal cord, were wider than the C7 and C8 segments. Preforaminal anterior compression at the C4-C5 disc level might affect the lower part of the C5 ventral rootlets and upper part of the C6 ventral rootlets. CONCLUSION: Short C5 ventral rootlets appeared to become taut and easily injured by hemilateral anterior compression. Spinal cord lesion resulting from localized anterior compression at the single disc level might not play as important a role in the pathogenesis of dissociated motor loss of the deltoid muscle because of the wider spinal segments of C5 and C6.

Aged↗
PubMed1995

Anatomic relation between the rectus capitis posterior minor muscle and the dura mater.

STUDY DESIGN: Anatomic study of the suboccipital region, specifically the deep muscles of the suboccipital triangle, was performed in cadaveric specimens. OBJECTIVE: To observe and describe the relationship between the deep suboccipital musculature and the spinal dura. SUMMARY OF BACKGROUND DATA: A review of the literature revealed no reports describing a physical connection between suboccipital musculature and the spinal dura. METHODS: Dissections of the suboccipital region were performed in 10 embalmed and one fresh sagittally hemisected head and neck specimens. RESULTS: A connective tissue bridge between the rectus capitis posterior minor muscle and the dorsal spinal dura at the atlanto-occipital junction was observed in every specimen. The fibers of the connective tissue bridge were oriented primarily perpendicular to the dura. This arrangement of fibers appears to resist movement of the dura toward the spinal cord. CONCLUSIONS: Awareness of the physical relation between the rectus capitis posterior minor muscle and spinal dura via this connective tissue bridge should lessen the potential risk of dural damage during surgery. This connective tissue bridge may help resist dural infolding during head and neck extension.

Adult↗
PubMed1996

The function of the long dorsal sacroiliac ligament: its implication for understanding low back pain.

STUDY DESIGN: In embalmed human bodies the tension of the long dorsal sacroiliac ligament was measured during incremental loading of anatomical structures that are biomechanically relevant. OBJECTIVES: To assess the function of the long dorsal sacroiliac ligament. SUMMARY OF BACKGROUND DATA: In many patients with aspecific low back pain or peripartum pelvic pain, pain is experienced in the region in which the long dorsal sacroiliac ligament is located. It is not well known that the ligament can be easily palpated in the area directly caudal to the posterior superior iliac spine. Data on the functional and clinical importance of this ligament are lacking. METHODS: A dissection study was performed on the sacral and lumbar regions. The tension of the long dorsal sacroiliac ligament (n = 12) was tested under loading. Tension was measured with a buckle transducer. Several structures, including the erector spinae muscle, the posterior layer of the thoracolumbar fascia, the sarcotuberous ligament, and the sacrum, were incrementally loaded (with forces of 0-50 newtons). The sacrum was loaded in two directions, causing nutation (ventral rotation of the sacrum relative to the iliac bones) and counternutation (the reverse). RESULTS: Forced nutation in the sacroiliac joints diminished the tension and forced counternutation increased the tension. Tension in the long dorsal sacroiliac ligament increased during loading of the ipsilateral sacrotuberous ligament and erector spinae muscle. The tension decreased during traction to the gluteus maximus muscle. Tension also decreased during traction to the ipsilateral and contralateral posterior layer of the thoracolumbar fascia in a direction simulating contraction of the latissimus dorsi muscle. CONCLUSIONS: The long dorsal sacroiliac ligament has close anatomical relations with the erector spinae muscle, the posterior layer of the thoracolumbar fascia, and a specific part of the sacrotuberous ligament (tuberoiliac ligament). Functionally, it is an important link between legs, spine, and arms. The ligament is tensed when the sacroiliac joints are counternutated and slackened when nutated. The reverse holds for the sacrotuberous ligament. Slackening of the long dorsal sacroiliac ligament can be counterbalanced by both the sacrotuberous ligament and the erector muscle. Pain localized within the boundaries of the long ligament could indicate among other things a spinal condition with sustained counternutation of the sacroiliac joints. In diagnosing patients with aspecific low back pain or peripartum pelvic pain, the long dorsal sacroiliac ligament should not be neglected. Even in cases of arthrodesis of the sacroiliac joints, tension in the long ligament can still be altered by different structures.

Aged↗
PubMed1996

Anatomic consideration of C2 pedicle screw placement.

STUDY DESIGN: This anatomic study tested placement of C2 pedicle screws using cadaver specimens. OBJECTIVES: To further assess the safety of transpedicular screw placement in the axis by comparing two surgical techniques. SUMMARY OF BACKGROUND DATA: Transpedicular screw fixation of traumatic spondylolisthesis of the axis has been described in the literature. Recently, anatomic studies and clinical applications of transpedicular screw fixation for traumatic lesions of middle and lower cervical spine have been described. No previous study assessing the safety of C2 pedicle screw placement is available. METHODS: Sixteen embalmed cadaveric specimens were used for this study. In the first eight specimens (Method A), the point of entry for screw placement was chosen to be about 5 mm inferior to the superior border of C2 lamina and 7 mm lateral to the lateral border of the spinal canal. The screw direction was chosen to be about 30 degrees medial to the sagittal plane and 20 degrees cephalad to the transverse plane. A 3.5-mm cortical screw of appropriate length, determined with depth gauge, was placed bilaterally into the C2 pedicle. In the next eight specimens (Method B), the direction of the drill bit was guided directly by the medial and superior aspect of the individual C2 pedicle. Gross dissection was done to view violation of dura, nerve roots, vertebral artery, and penetration of medial, lateral, superior, and inferior cortex of the C2 pedicle. Radiographs and computed tomography scans were obtained to evaluate screw placement in the C2 pedicle. RESULTS: In Method A, four screws had lateral violations into the vertebral artery. In Method B, only two cases of minimal penetration of pedicle cortex were found. No medial, superior, or inferior violation of the pedicle cortex was found in the present study. CONCLUSIONS: The present anatomic study suggests that transpedicular screw fixation may be performed safely in the C2 pedicle by using the second technique. Using the first technique is not safe.

Bone Screws↗
PubMed1996

Evaluation of cervical posterior lateral mass screw placement by oblique radiographs.

STUDY DESIGN: The present study analyzed the two-dimensional representation of cervical lateral mass screws by oblique radiographs compared with cadaveric placement. This was accomplished by posterior and lateral cervical dissection of the lateral masses and intervertebral foramina, keeping the emerging nerve roots intact. The intervertebral foramina were divided into two zones for the study. OBJECTIVES: To identify and describe the value of oblique radiographs in evaluating posterior lateral mass screw placement in the cervical spine. SUMMARY OF BACKGROUND DATA: Posterior plate-screw fixation is an effective method of stabilizing the traumatized cervical spine. Because of the surrounding anatomy, precise placement of screws must be attained to avoid iatrogenic injury to the nerve roots, and incorrectly placed screws must be identified quickly to minimize the neurologic complication. No previous radiologic study regarding evaluation of the lateral mass screw placement has been reported. METHODS: Six cervical spines were removed from embalmed cadavers. Posterior and lateral removal of soft tissue ensued until the lateral masses and spinal nerves were clearly and completely exposed. Two specimens and 20 screws were used for each of the following methods: Roy-Camille, zone 1 placement, and zone 2 placement. Zone 1 was defined as the area between pedicles of adjacent vertebrae. Zone 2 was defined as the area between transverse processes of adjacent vertebrae. Forty-five degrees oblique left and right, anteroposterior, and lateral radiographs were taken. RESULTS: All screws placed by the Roy-Camille technique and 19 of 20 screws intentionally placed in zone 1 were represented accurately by oblique radiographs. Nineteen of 20 screws placed in zone 1 were well appreciated in the foramen in oblique view. However, 13 of 20 screws placed in zone 2 and approximating the nerve root were inaccurately represented or ambiguous in oblique radiographs. CONCLUSIONS: Oblique radiographs are valuable to view the relationship between screw placement and foramina. Screws crossing the line connecting the posterior borders of the intervertebral foramina and appearing in the pedicle actually exit the bone and may risk damaging the nerve root.

Bone Screws↗
PubMed1997

Mechanical stability of thoracolumbar pedicle screw fixation. The effect of crosslinks.

STUDY DESIGN: Pedicle screw fixation for unstable thoracolumbar spine injuries is relatively new. The effect of one or two crosslinks on rotational and lateral bending stiffness was studied. OBJECTIVE: To determine the rotational and bending stiffness values of thoracolumbar fractures fixed by the AO's internal fixation system with zero, one, or two crosslinks. METHODS: Eight embalmed thoracolumbar spine segments. (T12-L2) were instrumented at T12 and L2 with a pedicle screw-rod system. Rotational stiffness was determined for 10 cycles to 2.5 degrees, 3.5 degrees, and 5 degrees of rotation, with and without one or two crosslinks, and lateral bending stiffness for 10 cycles to 0.25, 0.40, and 0.50 inch. The results showed a clear trend toward increased stiffness with crosslinks. RESULTS: The stiffness values of the two-crosslink construct at 2.5 degrees and 3.5 degrees of rotation were significantly higher than those of the zero-crosslink system. Also, the bending stiffness of the two-crosslink construct was significantly higher than that of no-crosslink system at all of the displacements. CONCLUSIONS: Rotational stiffness values of the two-crosslink construct were significantly higher than those of the zero-crosslink system, at 2.5 degrees and 3.5 degrees of rotation. Lateral bending stiffness of the two-crosslink system was higher than that of the zero-crosslink system at all levels of displacement.

Biomechanical Phenomena↗
PubMed1998

Lateral radiologic evaluation of lateral mass screw placement in the cervical spine.

STUDY DESIGN: Assessment of the value of lateral radiographs in evaluation of lateral mass screw placement in the cervical spine. OBJECTIVES: To assess the value of lateral radiographs in determining the safe or hazardous locations of the tips of screws used in lateral mass screw fixation. SUMMARY OF BACKGROUND DATA: Posterior plating with lateral mass screw fixation is frequently used to stabilize the cervical spine and improve fusion. Injury to the spinal nerves caused by screws that are too long must be identified quickly to minimize neurologic complication. No previous radiologic study in which lateral mass screw placement was evaluated using lateral radiographs has been reported. METHODS: Six cervical spines were removed from embalmed cadavers. Three screws using the Roy-Camille technique and another three using Magerl technique were placed into the lateral mass at C3-C5 in each specimen. Four screw placements under direct visualization, including placement of the screw tip staying the ventral cortex and 2-mm, 4-mm, and 6-mm overpenetration of the ventral cortex, were performed separately on each specimen for each of the two techniques. After each placement, a lateral radiograph was taken. Each vertebral body was divided vertically into four equal zones with Zone I the most posterior. Another equal zone, posterior to the posterior border of the vertebral body was defined as pre-Zone I. The number of screw tips seen in each zone were quantified for each placement. RESULTS: In the screws placed using the Roy-Camille technique, 77.8% of screws placed without perforating the ventral cortex were found in Zone I; 72.2% placed with 2-mm overpenetration of the ventral cortex were noted in Zone II; and 61.1% of the screws with 4-mm overpenetration of ventral cortex and 77.8% with 6-mm overpenetration were located in Zone III. For the use of the Magerl technique, 44.4% of the screws placed without perforating the ventral cortex were found in pre-Zone I; 72.2% of the screws placed with 2-mm overpenetration were located in Zone I; and 66.6% with 4-mm overpenetration and 89.7% with 6-mm overpenetration were noted in Zones I and II, respectively. CONCLUSIONS: Lateral radiographs may be valuable in evaluating lateral mass screw placement. Ideal screw tip positions on lateral radiograph for the Roy-Camille technique may be in Zone I, and for the Magerl technique may be in pre-Zone I.

Aged↗
PubMed1998

Anatomic considerations of anterior transarticular screw fixation for atlantoaxial instability.

STUDY DESIGN: Anatomic parameters of C1 and C2 were measured in 30 dried human cervical spines. Anterior transarticular C1-C2 screws were placed in 15 cadaveric spines. OBJECTIVE: To provide anatomic data for anterior transarticular atlantoaxial screw or C1-C2 screw and plate fixation. SUMMARY OF BACKGROUND DATA: A posterior approach to fixation in the atlantoaxial joint has been well described. Damage to the vertebral artery is documented as a rare complication of posterior atlantoaxial transarticular screw fixation. An anterior surgical approach to exposing the upper cervical spine for internal fixation and bone graft recently has been developed. No anatomic information regarding the anterior transarticular atlantoaxial screw or screw and plate fixation between C1 and C2 is available in the literature. METHODS: Direct measurements using digital calipers and a goniometer were taken from 30 pairs of dried human C1 and C2 vertebrae. The anterior transarticular C1-C2 screw insertion point is at the junction of the lateral edge of the C2 vertebral body to 4 mm above the inferior edge of the C2 anterior arch. The parameters related to anterior transarticular atlantoaxial screw fixation or screw and plate fixation between the C1 lateral mass and the C2 vertebral body were measured. Fifteen embalmed cadavers were used for anterior C1-C2 transarticular screw placement. Longer screws (30-40 mm) were used to detect whether the screw tips violated the upper cervical canal or vertebral arteries. RESULTS: In the anterior transarticular atlantoaxial screw placement, lateral angulation of the screw placement relative to sagittal plane ranged from 4.8 +/- 1.8 degrees to 25.3 +/- 2.6 degrees. The posterior angulation of the screw placement relative to the coronal plane ranged from 12.8 +/- 3.1 degrees to 22.6 +/- 3.2 degrees. The length of the medial screw path ranged from 14.7 +/- 1.5 mm to 25.4 +/- 2.8 mm. In the anterior screw and plate fixation, the anteroposterior diameter of the inferior facet articular surface ranged from 16.2 +/- 1.6 mm to 17.1 +/- 1.8 mm. The anteroposterior diameter of the C2 vertebral body ranged from 9.3 +/- 1 mm to 16.2 +/- 1.8 mm. The anterior prevascular retropharyngeal approach appropriately exposed the atlantoaxial joint for anterior transarticular C1-C2 screw placement. No screws violated the vertebral artery and cervical canal. CONCLUSIONS: An anterior transarticular atlantoaxial screw 15-25 mm long can be inserted with a lateral angulation of 5-25 degrees relative to the sagittal plane and a posterior angulation of 10-25 degrees relative to the coronal plane. Additionally, in C1-C2 anterior plate fixation screws 15 mm long could be anchored in the inferior facet of the C1, and screws 9-15 mm long could be anchored in the C2 vertebral body.

Aged↗