Cervical spinal motion during intubation: efficacy of stabilization maneuvers in the setting of complete segmental instability

2001 ◽  
Vol 94 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Peter J. Lennarson ◽  
Darin W. Smith ◽  
Paul D. Sawin ◽  
Michael M. Todd ◽  
Yutaka Sato ◽  
...  

Object. The purpose of this study was to characterize and compare segmental cervical motion during orotracheal intubation in cadavers with and without a complete subaxial injury, as well as to examine the efficacy of commonly used stabilization techniques in limiting that motion. Methods. Intubation procedures were performed in 10 fresh human cadavers in which cervical spines were intact and following the creation of a complete C4–5 ligamentous injury. Movement of the cervical spine during direct laryngoscopy and intubation was recorded using video fluoroscopy and examined under the following conditions: 1) without stabilization; 2) with manual in-line cervical immobilization; and 3) with Gardner—Wells traction. Subsequently, segmental angular rotation, subluxation, and distraction at the injured C4–5 level were measured from digitized frames of the recorded video fluoroscopy. Conclusions: After complete C4–5 destabilization, the effects of attempted stabilization on distraction, angulation, and subluxation were analyzed. Immobilization effectively eliminated distraction, and diminished angulation, but increased subluxation. Traction significantly increased distraction, but decreased angular rotation and effectively eliminated subluxation. Orotracheal intubation without stabilization had intermediate results, causing less distraction than traction, less subluxation than immobilization, but increased angulation compared with either intervention. These results are discussed in terms of both statistical and clinical significance and recommendations are made.

2000 ◽  
Vol 92 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Peter J. Lennarson ◽  
Darin Smith ◽  
Michael M. Todd ◽  
Douglas Carras ◽  
Paul D. Sawin ◽  
...  

Object. The purpose of this study was to establish a cadaveric model for evaluating cervical spine motion in both the intact and injured states and to examine the efficacy of commonly used stabilization techniques in limiting that motion. Methods. Intubation was performed in fresh human cadavers with intact cervical spines, following the creation of a C4–5 posterior ligamentous injury. Movement of the cervical spine during direct laryngoscopy and intubation was recorded using video fluoroscopy and examined under the following conditions: 1) without external stabilization; 2) with manual in-line cervical immobilization; and 3) with Gardner—Wells traction. Subsequently, segmental motion of the occiput through C-5 (Oc—C5) was measured from digitized frames of the recorded video fluoroscopy. The predominant motion, at all levels measured in the intact spine, was extension. The greatest degree of motion occurred at the atlantooccipital (Oc—C1) junction, followed by the C1–2 junction, with progressively less motion at each more caudal level. After posterior destabilization was induced, the predominant direction of motion at C4–5 changed from extension to flexion, but the degree of motion remained among the least of all levels measured. Traction limited but did not prevent motion at the Oc—C1 junction, but neither traction nor immobilization limited motion at the destabilized C4–5 level. Conclusions. Cadaveric cervical spine motion accurately reflected previously reported motion in living, anesthetized patients. Traction was the most effective method of reducing motion at the occipitocervical junction, but none of the interventions significantly reduced movement at the subaxial site of injury. These findings should be considered when treating injured patients requiring orotracheal intubation.


2000 ◽  
Vol 92 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Victor M. Haughton ◽  
Timothy A. Schmidt ◽  
Kevin Keele ◽  
Howard S. An ◽  
Tae-Hong Lim

Object. The authors conducted a study in which their objective was to measure the effect of tears in the annulus fibrosus on the motions of lumbar spinal motion segments. Methods. Lumbar spinal motion segments were harvested from human cadavers and studied using a 1.5-tesla magnetic resonance imager. The motion segments were subjected to incremental flexion, extension, rotation, and lateral bending torques. Displacements and rotations were measured using a kinematic system. The segments were sectioned on a cryomicrotome to verify the presence of tears in the annulus fibrosus. Conclusions. Tears in the annulus fibrosus increase the amount of motion that results from a torque applied to the motion segment. Radial and transverse tears of the annulus fibrosus have a greater effect on motions produced by an axial rotatory torque than on those produced by flexion, extension, or lateral bending torques. The difference between normal discs and discs with annular tears is more marked during moments of axial rotational than during those of flexion, extension, or lateral bending.


1974 ◽  
Vol 41 (6) ◽  
pp. 724-727 ◽  
Author(s):  
R. C. Saxena ◽  
M. A. Q. Beg ◽  
A. C. Das

✓ The dura mater of the posterior cranial fossa of 86 adult human cadavers has been examined grossly after the injection of India ink through the confluence of sinuses in order to visualize the extent, communications, and tributaries of the straight sinus. Variations from the textbook description of formation by the union of the inferior sagittal sinus and the great cerebral vein are described and discussed.


1995 ◽  
Vol 82 (6) ◽  
pp. 1011-1014 ◽  
Author(s):  
T. Glenn Pait ◽  
Phillip V. McAllister ◽  
Howard H. Kaufman

✓ Knowledge of the relevant anatomy is important when developing a strategy for introducing screws into the lateral masses to secure internal fixation devices. This paper defines key bony landmarks and their relationship to critical neurovascular structures and identifies a location for safe placement of cervical articular pillar (lateral mass) screws. Measurements of anatomical landmarks in 10 spines from human cadavers aged 61 to 85 years were made by caliper and a metric ruler. Landmarks were the lateral facet line, rostrocaudal line, medial facet line, intrafacet line, and medial facet line—vertebral artery line. The average distances and ranges were recorded. Such great variance existed in measurements from spine to spine and within the same spine as to render averages clinically unreliable. Dissection revealed that division of the articular pillar into four quadrants leaves one, the superior lateral quadrant, under which there are no neurovascular structures; this may be considered the “safe quadrant” for placement of posterior screws and plates.


2005 ◽  
Vol 102 (5) ◽  
pp. 910-911 ◽  
Author(s):  
R. Shane Tubbs ◽  
Elizabeth C. Tyler-Kabara ◽  
Alan C. Aikens ◽  
Justin P. Martin ◽  
Leslie L. Weed ◽  
...  

Object. There is a paucity of literature regarding the surgical anatomy of the dorsal scapular nerve (DSN). The aim of this study was to elucidate the relationship of this nerve to surrounding anatomical structures. Methods. Ten formalin-fixed human cadavers (20 sides) were dissected, and measurements made between the DSN and related structures. The nerve pierced the middle scalene muscle at a mean distance of 3 cm from its origin from the cervical spine and was more or less centrally located at this exit site. It lay a mean distance of 1.5 cm medial to the vertebral border of the scapula between the serratus posterior superior, posterior scalene, and levator scapulae muscles. It was found to have a mean distance of 2.5 cm medial to the spinal accessory nerve as it traveled on the anterior border of the trapezius muscle. The nerve intertwined the dorsal scapular artery in all specimens and was found along the anterior border of the rhomboid muscles. On 19 sides the DSN originated solely from the C-5 spinal nerve, and on one side it arose from the C-5 and C-6 spinal nerves. Conclusions. Knowledge of the anatomy of the DSN will aid the surgeon who wishes to explore and decompress this structure.


2004 ◽  
Vol 101 (5) ◽  
pp. 832-835 ◽  
Author(s):  
Mansoor Sharifi ◽  
Jacek Kunicki ◽  
Pawel Krajewski ◽  
Bogdan Ciszek

Object. Chordae willisii are structures located in the lumen of the superior sagittal sinus (SSS). It is thought that they act as flow-improving structures within the sinuses. There are few anatomical descriptions of chordae willisii, and all previous observations were performed through standard anatomical dissections. The purpose of this study was to visualize and describe structural and topographical features of the chordae willisii with the aid of rigid endoscopy. Methods. Twenty-five SSSs obtained from fresh human cadavers during autopsies were the material for this study. Specimens were flushed with tap water to remove clots. Bridging veins emptying into the sinus were ligated, and continuous flow of a saline solution through the sinus in a physiological direction was achieved by connecting the sinus to an irrigating system. Rigid endoscopes of different diameters (2.7–4.5 mm) and optic (0 and 30°) were inserted into the lumen of the sinus. The endoscope was connected to a digital camera and a video system to allow for recording of the observed structures. Finally, the sinuses were opened and the chordae willisii were dissected using standard anatomical methods. The chordae willisii were observed in all examined specimens. Three different types of the cords were found: lamellar, trabecular, and valvelike types. The most common type was the valvelike (mixed) one, which comprised 45.1% of all cords. The chordae willisii were most commonly observed in the parietooccipital region of the SSS. Conclusions. Witout disturbing any structural relationships, the use of endoscopy allowed visualization and description of intraluminal structures as they behaved physiologically.


2000 ◽  
Vol 92 (2) ◽  
pp. 197-200 ◽  
Author(s):  
R. Shane Tubbs ◽  
Paul Grabb ◽  
Alan Spooner ◽  
Wally Wilson ◽  
W. Jerry Oakes

Object. The authors conducted a study to describe the detailed anatomy of the apical ligament and to acknowledge or refute its historical description as a functionally significant contributor to craniocervical stability. Methods. In 20 adult human cadavers measurements of the apical ligament were obtained, and its detailed anatomy was observed. Ranges of motion were also assessed to discern the function of the apical ligament. Conclusions. Results of the study support the concept that the apical ligament is best described as a vestigial structure that offers no significant added stability to the craniocervical junction. In fact, this ligament was absent in 20% of the specimens examined. These data will aid physicians who frequently view images or manage clinical problems of the craniocervical junction because they may focus on other ligaments of this area and not the apical ligament.


2000 ◽  
Vol 93 (2) ◽  
pp. 252-258 ◽  
Author(s):  
Patrick W. Hitchon ◽  
Vijay K. Goel ◽  
Thomas N. Rogge ◽  
James C. Torner ◽  
Andrew P. Dooris ◽  
...  

Object. The goal of this study was to evaluate the comparative efficacy of three commonly used anterior thoracolumbar implants: the anterior thoracolumbar locking plate (ATLP), the smooth-rod Kaneda (SRK), and the Z-plate. Methods. In vitro testing was performed using the T9—L3 segments of human cadaver spines. An L-1 corpectomy was performed, and stabilization was achieved using one of three anterior devices: the ATLP in nine spines, the SRK in 10, and the Z-plate in 10. Specimens were load tested with 1.5-, 3-, 4.5-, and 6-Nm in flexion and extension, right and left lateral bending, and right and left axial rotation. Angular motion was monitored using two video cameras that tracked light-emitting diodes attached to the vertebral bodies. Testing was performed in the intact state in spines stabilized with one of the three aforementioned devices after the devices had been fatigued to 5000 cycles at ± 3 Nm and after bilateral facetectomy. There was no difference in the stability of the intact spines with use of the three devices. There were no differences between the SRK- and Z-plate—instrumented spines in any state. In extension testing, the mean angular rotation (± standard deviation) of spines instrumented with the SRK (4.7 ± 3.2°) and Z-plate devices (3.3 ± 2.3°) was more rigid than that observed in the ATLP-stabilized spines (9 ± 4.8°). In flexion testing after induction of fatigue, however, only the SRK (4.2 ± 3.2°) was stiffer than the ATLP (8.9 ± 4.9°). Also, in extension postfatigue, only the SRK (2.4 ± 3.4°) provided more rigid fixation than the ATLP (6.4 ± 2.9°). All three devices were equally unstable after bilateral facetectomy. The SRK and Z-plate anterior thoracolumbar implants were both more rigid than the ATLP, and of the former two the SRK was stiffer. Conclusions. The authors' results suggest that in cases in which profile and ease of application are not of paramount importance, the SRK has an advantage over the other two tested implants in achieving rigid fixation immediately postoperatively.


1996 ◽  
Vol 85 (5) ◽  
pp. 824-829 ◽  
Author(s):  
Edward C. Benzel ◽  
Blaine L. Hart ◽  
Perry A. Ball ◽  
Nevan G. Baldwin ◽  
William W. Orrison ◽  
...  

✓ Because it is often difficult to diagnose accurately the structurally intact cervical spine after acute trauma, a series of patients was evaluated with magnetic resonance (MR) imaging to assess its efficacy for the evaluation and clearance of the cervical spine in a trauma victim in the early posttrauma period. Ultralow-field MR imaging was used to evaluate 174 posttraumatic patients in whom physical findings indicated the potential for spine injury or minor radiographic findings indicated injury. This series includes only those patients who did not appear to harbor disruption of spinal integrity on the basis of a routine x-ray film. None had clinically obvious injury. Of the 174 patients, 62 (36%) had soft-tissue abnormalities identified by MR imaging, including disc interspace disruption in 27 patients (four with ventral and dorsal ligamentous injury, three with ventral ligamentous injury alone, 18 with dorsal ligamentous injury alone, and two without ventral or dorsal ligamentous injury). Isolated ligamentous injury was observed in 35 patients (eight with ventral and dorsal ligamentous injury, five with ventral ligamentous injury alone, and 22 with dorsal ligamentous injury alone). One patient underwent a surgical fusion procedure, 35 patients (including the one treated surgically) were placed in a cervical collar for at least 1 month, and 27 patients were placed in a thermoplastic Minerva jacket for at least 2 months. All had a satisfactory outcome without evidence of instability. The T2-weighted sagittal images were most useful in defining acute soft-tissue injury; axial images were of minimal assistance. Posttraumatic soft-tissue cervical spine injuries and disc herniations (most likely preexisting the trauma) are more common than expected. A negative MR image should be considered as confirmation of a negative or “cleared” subaxial cervical spine. Diagnostic and patient management algorithms may be appropriately tailored by this information. Thus, MR imaging is useful for early acute posttrauma assessment in a very select group of patients.


1973 ◽  
Vol 39 (4) ◽  
pp. 540-542 ◽  
Author(s):  
R. C. Saxena ◽  
M. A. Q. Beg ◽  
A. C. Das

✓ The straight sinus was examined in 43 human cadavers. In 13.95% of the cadavers the straight sinus was double, being either median in position, that is, one was superior and the other inferior (9.3%), or paramedian, that is, both lay side by side on either side of the midline at the junction of the falx cerebri with the tentorium cerebelli (4.65%).


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