scholarly journals Posterior arch C-1 screw technique: a cadaveric comparison study

2017 ◽  
Vol 26 (6) ◽  
pp. 679-683 ◽  
Author(s):  
Marc Moisi ◽  
Christian Fisahn ◽  
Lara Tkachenko ◽  
Shiveindra Jeyamohan ◽  
Stephen Reintjes ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Nerve Root ◽  
Access Point ◽  
Screw Placement ◽  
Posterior Arch ◽  
Lateral Mass ◽  
Entry Site ◽  
Starting Point ◽  
The Right

OBJECTIVEPosterior atlantoaxial stabilization and fusion using C-1 lateral mass screw fixation has become commonly used in the treatment of instability and for reconstructive indications since its introduction by Goel and Laheri in 1994 and modification by Harms in 2001. Placement of such lateral mass screws can be challenging because of the proximity to the spinal cord, vertebral artery, an extensive venous plexus, and the C-2 nerve root, which overlies the designated starting point on the posterior center of the lateral mass. An alternative posterior access point starting on the posterior arch of C-1 could provide a C-2 nerve root–sparing starting point for screw placement, with the potential benefit of greater directional control and simpler trajectory. The authors present a cadaveric study comparing an alternative strategy (i.e., a C-1 screw with a posterior arch starting point) to the conventional strategy (i.e., using the lower lateral mass entry site), specifically assessing the safety of screw placement to preserve the C-2 nerve root.METHODSFive US-trained spine fellows instrumented 17 fresh human cadaveric heads using the Goel/Harms C-1 lateral mass (GHLM) technique on the left and the posterior arch lateral mass (PALM) technique on the right, under fluoroscopic guidance. After screw placement, a CT scan was obtained on each specimen to assess for radiographic screw placement accuracy. Four faculty spine surgeons, blinded to the surgeon who instrumented the cadaver, independently graded the quality of screw placement using a modified Upendra classification.RESULTSOf the 17 specimens, the C-2 nerve root was anatomically impinged in 13 (76.5%) of the specimens. The GHLM technique was graded Type 1 or 2, which is considered “acceptable,” in 12 specimens (70.6%), and graded Type 3 or 4 (“unacceptable”) in 5 specimens (29.4%). In contrast, the PALM technique had 17 (100%) of 17 graded Type 1 or 2 (p = 0.015). There were no vertebral artery injuries found in either technique. All screw violations occurred in the medial direction.CONCLUSIONSThe PALM technique showed statistically fewer medial penetrations than the GHLM technique in this study. The reason for this is not clear, but may stem from a more angulated ”up-and-in” screw direction necessary with a lower starting point.

Posterior C1 Stabilization Using Superior Lateral Mass as an Entry Point in a Case With Vertebral Artery Anomaly: Technical Case Report

2011 ◽  
Vol 68 (suppl_1) ◽  
pp. onsE246-onsE249 ◽  
Author(s):  
Jae Taek Hong ◽  
Woo Young Jang ◽  
Il Sup Kim ◽  
Seung Ho Yang ◽  
Jae Hoon Sung ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Vertebral Artery ◽  
Computed Tomography Angiography ◽  
Anatomical Variations ◽  
Entry Point ◽  
Screw Placement ◽  
Lateral Mass ◽  
Starting Point ◽  
Bursting Fracture ◽  
The Right

Abstract BACKGROUND AND IMPORTANCE: This is the first report of using the superior lateral mass as an alternative starting point for C1 posterior screw placement, demonstrating the importance of recognizing vertebral artery (VA) anomaly in deciding the surgical strategy for C1 screw placement. CLINICAL PRESENTATION: A 56-year-old man presented with severe neck pain after a fall. Imaging demonstrated an unstable bursting fracture at C4, C1-2 instability, and a subluxation at C2-3. Computed tomography angiography indicated that the persistent first intersegmental artery was located on the left side. The patient underwent anterior-posterior cervical fixation and fusion. Posterior C1 fixation was done with polyaxial screw rod construct using C1 superior lateral mass on the left side and C1 inferior lateral mass on the right side. The patient had no immediate postoperative deficits. At the 8-month follow-up examination, the patient was neurologically intact with a solid cervical fusion. CONCLUSION: The third segment of the VA is heterogeneous; therefore, preoperative radiologic studies should be performed to identify any anatomical variations. Using preoperative 3-dimensional computed tomography angiography, we can precisely identify an anomalous VA, thereby significantly reducing the risk of VA injury. To avoid significant morbidities associated with VA injury, a more optimal entry point for C1 fixation can be selected if a persistent first intersegmental artery or fenestrated VA is detected.

Morphometric Anatomy of the Posterior Aspect of the Atlas and the Vertebral Artery Groove in Relation to Lateral Mass Screw Placement

2021 ◽  
Author(s):  
Selda Aksoy ◽  
Bulent Yalcin
Keyword(s):  
Vertebral Artery ◽  
Screw Placement ◽  
Atlantoaxial Instability ◽  
Posterior Arch ◽  
Lateral Mass ◽  
Lateral Mass Screw ◽  
Entry Zone ◽  
Mean Width ◽  
The Mean ◽  
The Right

Abstract Background Atlantoaxial instability is an important disorder that causes serious symptoms such as difficulties in walking, limited neck mobility, sensory deficits, etc. Atlantal lateral mass screw fixation is a surgical technique that has gained important recognition and popularity. Because accurate drilling area for screw placement is of utmost importance for a successful surgery, we aimed to investigate morphometry of especially the posterior part of C1. Methods One hundred and fifty-eight human adult C1 dried vertebrae were obtained. Measurements were performed directly on dry atlas vertebrae, and all parameters were measured by using a digital caliper accurate to 0.01 mm for linear measurements. Results The mean distance between the tip of the posterior arch and the medial inner edge of the groove was found to be 10.59 ± 2.26 and 10.49 ± 2.20 mm on the right and left, respectively. The mean distance between the tip of the posterior arch and the anterolateral outer edge of the groove was 21.27 ± 2.28 mm (right: 20.96 ± 2.22 mm; left: 21.32 ± 2.27 mm). The mean height of the screw entry zone on the right and left sides, respectively, were 3.86 ± 0.81 and 3.84 ± 0.77 mm. The mean width of the screw entry zone on both sides was 13.15 ± 1.17 and 13.25 ± 1.3 mm. Conclusion Our result provided the literature with a detailed database for the morphometry of C1, especially in relation to the vertebral artery groove. We believe that the data in the present study can help surgeons to adopt a more accurate approach in terms of accurate lateral mass screw placement in atlantoaxial instability.

Factors affecting lateral mass screw placement at C-7

2011 ◽  
Vol 14 (3) ◽  
pp. 405-411 ◽  
Author(s):  
Kalil G. Abdullah ◽  
Amy S. Nowacki ◽  
Michael P. Steinmetz ◽  
Jeffrey C. Wang ◽  
Thomas E. Mroz
Keyword(s):  
Sagittal Plane ◽  
Anatomical Variation ◽  
Axial Plane ◽  
Screw Placement ◽  
Lateral Mass ◽  
Lateral Mass Screw ◽  
Modified Technique ◽  
Modified Method ◽  
Starting Point ◽  
Lateral Mass Screws

Object The C-7 lateral mass has been considered difficult to fit with instrumentation because of its unique anatomy. Of the methods that exist for placing lateral mass screws, none particularly accommodates this anatomical variation. The authors have related 12 distinct morphological measures of the C-7 lateral mass to the ability to place a lateral mass screw using the Magerl, Roy-Camille, and a modified Roy-Camille method. Methods Using CT scans, the authors performed virtual screw placement of lateral mass screws at the C-7 level in 25 male and 25 female patients. Complications recorded included foraminal and articular process violations, inability to achieve bony purchase, and inability to place a screw longer than 6 mm. Violations were monitored in the coronal, axial, and sagittal planes. The Roy-Camille technique was applied starting directly in the middle of the lateral mass, as defined by Pait's quadrants, with an axial angle of 15° lateral and a sagittal angle of 90°. The Magerl technique was performed by starting in the inferior portion of the top right square of Pait's quadrants and angling 25° laterally in the axial plane with a 45° cephalad angle in the sagittal plane. In a modified method, the starting point is similar to the Magerl technique in the top right square of Pait's quadrant and then angling 15° laterally in the axial plane. In the sagittal plane, a 90° angle is taken perpendicular to the dorsal portion of the lateral mass, as in the traditional Roy-Camille technique. Results Of all the morphological methods analyzed, only a combined measure of intrusion of the T-1 facet and the overall length of the C-7 lateral mass was statistically associated with screw placement, and only in the Roy-Camille technique. Use of the Magerl technique allowed screw placement in 28 patients; use of the Roy-Camille technique allowed placement in 24 patients; and use of the modified technique allowed placement in 46 patients. No screw placement by any method was possible in 4 patients. Conclusions There is only one distinct anatomical ratio that was shown to affect lateral mass screw placement at C-7. This ratio incorporates the overall length of the lateral mass and the amount of space occupied by the T-1 facet at C-7. Based on this virtual study, a modified Roy-Camille technique that utilizes a higher starting point may decrease the complication rate at C-7 by avoiding placement of the lateral mass screw into the T1 facet.

scholarly journals Posterior spinal fusion using a unilateral C1 posterior arch screw and a C2 laminar screw for atlantoaxial fracture dislocation

2019 ◽  
Vol 7 ◽  
pp. 2050313X1984927 ◽  
Author(s):  
Yuichi Ono ◽  
Naohisa Miyakoshi ◽  
Michio Hongo ◽  
Yuji Kasukawa ◽  
Yoshinori Ishikawa ◽  
...  
Keyword(s):  
Pedicle Screws ◽  
Fracture Site ◽  
Fracture Dislocation ◽  
Posterior Arch ◽  
Lateral Mass ◽  
Laminar Screw ◽  
Upper Cervical ◽  
Lateral Mass Screws ◽  
The Right ◽  
C2 Laminar Screw

Introduction: C1 lateral mass screws and C2 pedicle screws are usually chosen to fix atlantoaxial (C1–C2) instability. However, there are a few situations in which these screws are difficult to use, such as in a case with a fracture line at the screw insertion point and bleeding from the fracture site. A new technique using a unilateral C1 posterior arch screw and a C2 laminar screw combined with a contralateral C1 lateral mass screws–C2 pedicle screws procedure for upper cervical fixation is reported. Case Report: A 24-year-old woman had an irreducible C1–C2 anterior dislocation with a type III odontoid fracture on the right side due to a traffic accident. The patient underwent open reduction and posterior C1–C2 fixation. On the left side, a C1 lateral mass screws and a C2 pedicle screws were placed. Because there was bleeding from the fracture site and a high-riding vertebral artery was seen on the right side, a C1 posterior arch screw and a C2 laminar screw were chosen. Eight months after the surgery, computed tomography scans showed healing of the odontoid fracture with anatomically correct alignment. Conclusions: Although there have been few comparable studies, fixation with unilateral C1 posterior arch screw–C2 laminar screw could be a beneficial choice for surgeries involving the upper cervical region in patients with fracture dislocation or arterial abnormalities.

Vascular decompression of a vertebral artery loop producing cervical radiculopathy

1998 ◽  
Vol 89 (3) ◽  
pp. 485-488 ◽  
Author(s):  
Paul W. Detwiler ◽  
Randall W. Porter ◽  
Timothy R. Harrington ◽  
Volker K. H. Sonntag ◽  
Robert F. Spetzler
Keyword(s):  
Vertebral Artery ◽  
Nerve Root ◽  
Cervical Radiculopathy ◽  
Vascular Structure ◽  
Loop Formation ◽  
Content Type ◽  
History Of ◽  
Radicular Symptoms ◽  
The Right ◽  
Vascular Decompression

✓ Vertebral artery tortuosity and loop formation are rare causes of cervical radiculopathy. The authors present the case of a 70-year-old man with 9 years of progressive right-sided cervical and scapular pain but no history of trauma. Computerized tomography myelography and magnetic resonance imaging revealed an ovoid mass in the right C3–4 intervertebral foramen. The patient underwent a right C-3 and C-4 hemilaminectomy and a complete C3–4 facetectomy. A pulsatile vascular structure was found compressing the right C-4 nerve root. The bone overlying the vascular structure was removed, producing decompression of the nerve root. Immediate postoperative angiography showed that this lesion was a focal vertebral artery loop. The patient's symptoms resolved after surgery, supporting the use of vascular decompression of a cervical nerve root compressed by a vertebral artery loop for the relief of radicular symptoms.

Bow Hunter's Syndrome: Complete Microsurgical Decompression of Vertebral Artery by Far Lateral Retrocondylar Approach: 3-Dimensional Operative Video

2019 ◽  
Author(s):  
Qazi Zeeshan ◽  
Juan P Carrasco Hernandez ◽  
Laligam N Sekhar
Keyword(s):  
Vertebral Artery ◽  
Nerve Root ◽  
Dynamic Compression ◽  
Skin Incision ◽  
Left Vertebral Artery ◽  
Occipital Condyle ◽  
Cerebral Angiogram ◽  
Microsurgical Decompression ◽  
C2 Nerve Root ◽  
The Right

Abstract This 50-yr-old man had a 15-yr history of presyncopal episodes that were precipitated by turning his head to the right, and had worsened recently. Cerebral angiogram demonstrated complete cessation of anterograde flow in left vertebral artery (VA) at the level of the C1 sulcus arteriosus while turning head to right, indicating dynamic compression at the C1 level.  Patient underwent left extreme lateral retrocondylar approach, partial C1 laminectomy and opening of the C1 foramen with complete microsurgical decompression of the VA. After skin incision, meticulous muscle dissection was performed and superior and inferior oblique muscles were disconnected from the tubercle of C1. The VA was exposed, and three areas of constriction were visible, first at the atlanto-occipital membrane laterally; second, located more medially as the artery curved around the occipital condyle to enter the posterior fossa; and third, located anterior to C2 nerve root. The artery was dissected from all the surrounding tissues, preserving the C2 nerve root, and the Cl foramen was opened completely. The Cl lamina was also partially resected and grooved to allow free placement of the VA. The VA was also decompressed near the C2 foramen. Postoperative computed tomography angiogram of the head and neck showed complete decompression of VA. The patient had no episodes of presyncope or dizziness while turning head to right and his mRs was 0 at 8 mo follow up.  This 3D video shows the technical nuances of decompression of V3 segment of VA in bow hunters's syndrome.  Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.

Stent-assisted coil embolization for an unruptured vertebral artery–posterior inferior cerebellar artery aneurysm with retrograde access via type 1 persistent primitive proatlantal artery: A case report

2020 ◽  
pp. 159101992097384
Author(s):  
Yasuhiko Nariai ◽  
Tomoji Takigawa ◽  
Ryotaro Suzuki ◽  
Akio Hyodo ◽  
Kensuke Suzuki
Keyword(s):  
Carotid Artery ◽  
Vertebral Artery ◽  
Coil Embolization ◽  
Posterior Inferior Cerebellar Artery ◽  
External Carotid ◽  
Proatlantal Artery ◽  
Cerebellar Artery ◽  
The Right ◽  
Pica Aneurysms

Vertebral artery (VA)-posterior inferior cerebellar artery (PICA) aneurysms are rare lesions that are difficult to treat with both endovascular and surgical techniques. Tight angulation of the PICA from VA may make access to the PICA difficult from ipsilateral VA if adjunctive techniques are needed. Recently, the safety and efficacy of retrograde access have been reported. We report a case of endovascular treatment for a VA-PICA aneurysm with a stent-assisted technique using retrograde access via contralateral persistent primitive proatlantal artery (PPA). The patient was a 76-year-old woman with an unruptured VA-PICA aneurysm on the dominant VA side. Coil embolization with a stent-assisted technique using retrograde access seemed appropriate. However, the origin of the left VA was not confirmed. Left common carotid artery angiography demonstrated that the PPA (type 1) branching from external carotid artery joined the VA V4 segment. Retrograde access via the PPA for stenting was performed. A microcatheter for stenting was retrogradely advanced to the right PICA at ease. After deploying the stent, coil insertion was completed from the right VA, and the final angiogram showed adequate occlusion of the aneurysm with preservation of the PICA. Thus, PPA may be an approach route in the treatment of VA-PICA aneurysms with unconfirmed contralateral VA orifice and apparent PPA on angiography, when retrograde access is needed.

scholarly journals VARIATIONS OF FORAMEN TRANSVERSARIUM IN ATLAS VERTEBRAE : A MORPHOLOGICAL STUDY WITH ITS CLINICAL SIGNIFICANCE

2015 ◽  
Vol 05 (02) ◽  
pp. 080-083 ◽  
Author(s):  
Qudusia Sultana ◽  
Ramakrishna Avadhani ◽  
Varalakshmi KL ◽  
Shariff MH ◽  
Keyword(s):  
Vertebral Artery ◽  
Clinical Significance ◽  
Morphological Study ◽  
Posterior Arch ◽  
Neck Injuries ◽  
Venous Plexus ◽  
Cerebrovascular Accidents ◽  
Cervical Injuries ◽  
The Right

Abstract Introduction: The second part of the vertebral artery along with vertebral venous plexus and sympathetic plexus traverses through vicinity of foramen transversarium of atlas. Derangement of these structures in their course may be seen due to deformities, narrowing and presence of osteophytes in foramen transversarium. Methods: Two hundred foramen transversarium of 100 atlas vertebrae were grossly studied for their variations. Results: Out of hundred atlas vertebrae examined, we found that all the vertebrae had foramina transversaria. Absence of costal element was noticed in five atlas vertebrae. 2 of the vertebrae showed incomplete unilateral foramen transversarium, 3 vertebrae showed bilateral incomplete foramen, In 1 vertebra along with normal foramen transversarium, complete retroarticular foramen was observed on the left side and incomplete retroarticular foramen observed on the right side of the posterior arch.4 vertebrae showed incomplete retroarticular foramen. Conclusion: The increasing incidence of neck injuries and related syndromes necessitates the study of bony variations of the atlas vertebra and its transverse foramina. Due to the incomplete formation of the foramen transversarium the second part of vertebral artery is prone to be damaged easily during posterior cervical injuries and Surgeries. The bony bridges embracing the vertebral artery may be responsible for vertigo and cerebrovascular accidents hence the knowledge of such variations is important for Physicians, Otirhinolaryngologists, neurologists ,Orthopaedicians and Radiologists.

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