Managing the Anomalous Vertebral Artery in C1–C2 Stabilization for Congenital Atlantoaxial Instability

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0040-1714404 ◽

2020 ◽

Author(s):

Roopesh Kumar Vadivel Rathakrishnan ◽

Sunil Kapilavayi Raghavendra

Keyword(s):

Vertebral Artery ◽

Soft Tissues ◽

Joint Space ◽

Atlantoaxial Instability ◽

Atlantoaxial Joint ◽

Transarticular Screw ◽

Surgical Strategies ◽

Harms Technique ◽

Atlas And Axis ◽

Operative Microscope

Abstract Objectives This study aimed to demonstrate the technique of handling the anomalous vertebral artery in congenital atlantoaxial instability. The vertebral artery course can be variable in congenital atlantoaxial instability, especially if there is assimilation of atlas. The surgical technique to stabilize the atlantoaxial joint should ensure the patency and safety of the vertebral artery and prevents devastating stroke. Computed tomography (CT) angiography of the vertebral artery is mandatory in planning the surgical strategies. The vertebral artery can be injured during dissection of soft tissues between atlas and axis and can be compromised during distraction and instrumentation. The vertebral artery needs to be mobilized based on the tortuosity in the course during instrumentation and prevents compression of the artery against bony structures or screw heads. The vertebral artery has to be identified earlier in the course of dissection and should protect it. It is also imperative to choose the surgical approach that can be performed under vision using operative microscope rather than adapting blind procedures like transarticular screw. Here, in our present case, we demonstrate the technique of mobilizing the vertebral artery which was coursing medially preventing the access for the instrumentation and perform stabilization of atlantoaxial joint using Goel–Harms technique, and prevent its compression after placement of screw by deroofing the bony ridges of axis (Figs. 1 and 2). We also emphasize the various technical nuances during the stabilization with distraction of joint space of atlas and axis.The link to the video can be found at: https://youtu.be/pgURpF_jACc.

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C2 laminar screw and C1-2 transarticular screw combined with C1 laminar hooks for atlantoaxial instability with unilateral vertebral artery injury

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-011-1277-6 ◽

2011 ◽

Vol 131 (9) ◽

pp. 1207-1210 ◽

Cited By ~ 6

Author(s):

Qunfeng Guo ◽

Jun Liu ◽

Bin Ni ◽

Xuhua Lu ◽

Fengjin Zhou

Keyword(s):

Vertebral Artery ◽

Vertebral Artery Injury ◽

Atlantoaxial Instability ◽

Transarticular Screw ◽

Artery Injury ◽

Laminar Screw ◽

Laminar Hooks ◽

C2 Laminar Screw

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The anatomical suitability of C1-2 transarticular screw placement in pediatric patients

Neurosurgical FOCUS ◽

10.3171/foc.1999.6.6.9 ◽

1999 ◽

Vol 6 (6) ◽

pp. E8

Author(s):

Douglas L. Brockmeyer ◽

Julie E. York ◽

Ronald I. Apfelbaum

Keyword(s):

Pediatric Patients ◽

Screw Fixation ◽

Pediatric Population ◽

Vascular Complications ◽

Joint Space ◽

Screw Placement ◽

Atlantoaxial Instability ◽

Os Odontoideum ◽

Transarticular Screw ◽

Transarticular Screw Fixation

Craniovertebral instability is a challenging problem in pediatric spinal surgery. Recently, C1-2 transarticular screw fixation in pediatric patients has been used to assist in the stabilization of the craniovertebral joint. Currently there are no data that define the anatomical suitability of this technique in the pediatric population. The authors report their experience in 32 pediatric patients in whom craniovertebral instability was treated by placement of C1-2 transarticular screws. From March 1991 to October 1998, 32 patients 16 years of age or younger with atlantooccipital, or atlantoaxial instability, or both were evaluated at our institution. There were 22 boys and 10 girls. Their ages ranged from 4 to 16 years (mean age 10.2 years). The most common causes of instability were os odontoideum (12 patients) and ligamentous laxity (nine patients). Six patients had undergone a total of nine previous attempts at posterior fusion at outside institutions. All patients underwent extensive preoperative radiological evaluation including thin cut (1-mm) computerized tomography scanning with multiplanar reconstruction to evaluate the C1-2 joint space anatomy. Of the 64 possible C1-2 joint spaces in 32 patients, 55 sides (86%) were considered suitable for transarticular screw placement preoperatively. In three patients the C1-2 joint space anatomy was considered unsuitable for screw placement bilaterally. In three patients the anatomy was considered inadequate on one side. Fifty-five C1-2 transarticular screws were subsequently placed, with no resulting neurological or vascular complications. We conclude that C1-2 transarticular screw fixation is technically possible in a large proportion of pediatric patients with craniovertebral instability.

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Stabilization of the atlantoaxial complex via C-1 lateral mass and C-2 pedicle screw fixation in a multicenter clinical experience in 102 patients: modification of the Harms and Goel techniques

Journal of Neurosurgery Spine ◽

10.3171/spi/2008/8/3/222 ◽

2008 ◽

Vol 8 (3) ◽

pp. 222-229 ◽

Cited By ~ 104

Author(s):

Henry E. Aryan ◽

C. Benjamin Newman ◽

Eric W. Nottmeier ◽

Frank L. Acosta ◽

Vincent Y. Wang ◽

...

Keyword(s):

Screw Fixation ◽

Case Series ◽

Pedicle Screws ◽

Joint Space ◽

Atlantoaxial Instability ◽

Lateral Mass ◽

X Ray ◽

Harms Technique ◽

Flexion And Extension

Object Stabilization of the atlantoaxial complex has proven to be very challenging. Because of the high mobility of the C1–2 motion segment, fusion rates at this level have been substantially lower than those at the subaxial spine. The set of potential surgical interventions is limited by the anatomy of this region. In 2001 Jürgen Harms described a novel technique for individual fixation of the C-1 lateral mass and the C-2 pedicle by using polyaxial screws and rods. This method has been shown to confer excellent stability in biomechanical studies. Cadaveric and radiographic analyses have indicated that it is safe with respect to osseous and vascular anatomy. Clinical outcome studies and fusion rates have been limited to small case series thus far. The authors reviewed the multicenter experience with 102 patients undergoing C1–2 fusion via the polyaxial screw/rod technique. They also describe a modification to the Harms technique. Methods One hundred two patients (60 female and 42 male) with an average age of 62 years were included in this analysis. The average follow-up was 16.4 months. Indications for surgery were instability at the C1–2 level, and a chronic Type II odontoid fracture was the most frequent underlying cause. All patients had evidence of instability on flexion and extension studies. All underwent posterior C-1 lateral mass to C-2 pedicle or pars screw fixation, according to the method of Harms. Thirty-nine patients also underwent distraction and placement of an allograft spacer into the C1–2 joint, the authors' modification of the Harms technique. None of the patients had supplemental sublaminar wiring. Results All but 2 patients with at least a 12-month follow-up had radiographic evidence of fusion or lack of motion on flexion and extension films. All patients with an allograft spacer demonstrated bridging bone across the joint space on plain x-ray films and computed tomography. The C-2 root was sacrificed bilaterally in all patients. A postoperative wound infection developed in 4 patients and was treated conservatively with antibiotics and local wound care. One patient required surgical debridement of the wound. No patient suffered a neurological injury. Unfavorable anatomy precluded the use of C-2 pedicle screws in 23 patients, and thus, they underwent placement of pars screws instead. Conclusions Fusion of C1–2 according to the Harms technique is a safe and effective treatment modality. It is suitable for a wide variety of fracture patterns, congenital abnormalities, or other causes of atlantoaxial instability. Modification of the Harms technique with distraction and placement of an allograft spacer in the joint space may restore C1–2 height and enhance radiographic detection of fusion by demonstrating a graft–bone interface on plain x-ray films, which is easier to visualize than the C1–2 joint.

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Posterior atlantoaxial stabilization: new alternative to C1–2 transarticular screws

Neurosurgical FOCUS ◽

10.3171/foc.2002.12.1.7 ◽

2002 ◽

Vol 12 (1) ◽

pp. 1-5 ◽

Cited By ~ 46

Author(s):

John K. Stokes ◽

Alan T. Villavicencio ◽

Paul C. Liu ◽

Robert S. Bray ◽

J. Patrick Johnson

Keyword(s):

Nerve Root ◽

Pedicle Screws ◽

Atlantoaxial Instability ◽

Atlantoaxial Joint ◽

Lateral Mass ◽

Success Rates ◽

Fixation Procedure ◽

Transarticular Screw ◽

Precise Knowledge ◽

Flexion Extension

Object Surgical treatment of atlantoaxial instability has evolved to include various posterior wiring techniques including Brooks, Gallie, and Sonntag fusions in which success rates range from 60 to 100%. The Magerl–Seemans technique in which C1–2 transarticular screws are placed results in fusion rates between 87 and 100%. This procedure is technically demanding and requires precise knowledge of the course of the vertebral arteries (VAs). The authors introduce a new C1–2 fixation procedure in which C-1 lateral mass and C-2 pedicle screws are placed that may have advantages over C1–2 transarticular screw constructs. Methods A standard posterior C1–2 exposure is obtained. Polyaxial C-2 pedicle screws and C-1 lateral mass screws are placed bilaterally. Rods are connected to the screws and secured using locking nuts. A cross-link is then placed. Fusion can be performed at the atlantoaxial joint by elevating the C-2 nerve root. The technique for this procedure has been used in four cases of atlantoaxial instability at the author's institution. There have been no C-2 nerve root– or VA-related injuries. No cases of construct failure have been observed in the short-term follow up period. Conclusions Atlantoaxial lateral mass and axial pedicle screw fixation offers an alternative means of achieving atlantoaxial fusion. The technique is less demanding than that required for transarticular screw placement and may avoid the potential complication of VA injury. The cross-linked construct is theoretically stable in flexion, extension, and rotation. Laminectomy or fracture of the posterior elements does not preclude use of this fixation procedure.

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Arteriovenous fistula as a complication of C1–2 transarticular screw fixation

Journal of Neurosurgery ◽

10.3171/jns.1996.85.2.0340 ◽

1996 ◽

Vol 85 (2) ◽

pp. 340-343 ◽

Cited By ~ 99

Author(s):

Domagoj Coric ◽

Charles L. Branch ◽

John A. Wilson ◽

James C. Robinson

Keyword(s):

Vertebral Artery ◽

Arteriovenous Fistula ◽

Screw Fixation ◽

Atlantoaxial Instability ◽

Unusual Complication ◽

Venous Plexus ◽

Fixation Technique ◽

Transarticular Screw ◽

Content Type ◽

Transarticular Fixation

✓ A case is reported of a vertebral artery-to-epidural venous plexus fistula as a complication of posterior atlantoaxial facet screw fixation. The use of transarticular screws to stabilize the C1–2 joint has become an increasingly popular fixation technique, most notably for atlantoaxial instability due to trauma or rheumatoid disease. Despite the fact that this approach is technically challenging, there have been few reports of complications associated with C1–2 transarticular fixation. Although damage to the vertebral artery is a documented hazard of transarticular fixation at this level, a symptomatic arteriovenous fistula resulting from the procedure has not been described previously. The etiology, presentation, and treatment of this unusual complication are discussed.

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Biomechanical Comparison of Two Atlantoaxial Arthrodeses in a Cadaveric Spine Model: Transarticular Screw Fixation Versus Screw and Rod Fixation

Advances in Bioengineering ◽

10.1115/imece2002-32631 ◽

2002 ◽

Author(s):

V. K. Goel ◽

H. Kuroki ◽

S. Holekamp ◽

V. Pitka¨nen ◽

S. Rengachary ◽

...

Keyword(s):

Vertebral Artery ◽

Screw Fixation ◽

Atlantoaxial Instability ◽

Transarticular Screw ◽

Transarticular Screw Fixation ◽

Risk Of Injury ◽

Spine Model ◽

Fixation Techniques ◽

A New Technique ◽

Biomechanical Comparison

The causes of atlantoaxial instability include trauma, tumor, congenital malformation, or rheumatoid arthritis. Commonly available fixation techniques to stabilize the atlantoaxial complex are several posterior wiring procedures (Brooks fusion, Gallie fusion), transarticular screw procedure (Magerl technique), either alone or in combination. Wiring procedures are obviously easier to accomplish however these do not provide sufficient immobilization across the atlantoaxial complex1,3,4. On the other hand, although transarticular screw fixation (TSF) affords a much stiffer atlantoaxial arthrodesis than posterior wiring procedures. However, TSF has some drawbacks; for example the injury of vertebral artery. Furthermore, body habitus (obesity or thoracic kyphosis) may prevent from achieving the low angle needed for correct placement of screws between C1 and C2. Recently, a new technique of screw and rod fixation (SRF) that minimizes the risk of injury to the vertebral artery and allows intraoperative reduction has been reported2,6. The purpose of this study was to compare the biomechanical stability imparted to the C1 and C2 vertebrae by either TSF or SRF technique in a cadaver model.

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Atlantoaxial Transarticular Screw Fixation

Neurosurgery ◽

10.1227/01.neu.0000365798.53288.a3 ◽

2010 ◽

Vol 66 (suppl_3) ◽

pp. A184-A192 ◽

Cited By ~ 49

Author(s):

Michael A. Finn ◽

Ronald I. Apfelbaum

Keyword(s):

Vertebral Artery ◽

Senior Author ◽

Bony Union ◽

Atlantoaxial Joint ◽

Transarticular Screw ◽

3 Dimensional ◽

The Mean ◽

Age Range ◽

Stable Internal Fixation

Abstract BACKGROUND Transarticular screw (TAS) fixation is our preferred method for stable internal fixation of the atlantoaxial joint because of its excellent outcomes, versatility, and cost-effectiveness. OBJECTIVE In this article, we update our series of patients who have undergone TAS fixation, with attention to surgical technique, planning, complication avoidance, and anatomic suitability. METHODS We retrospectively reviewed 269 patients (150 women, 119 men; average age, 52.9 years; age range, 17–90 years) who underwent placement of at least 1 TAS. In total, 491 TASs were placed for stabilization necessitated by various pathologic conditions. The mean follow-up period was 15.7 months (range, 0–106 months). RESULTS Fusion was achieved in 99% of 198 patients monitored until fusion or nonunion requiring revision, or for 2 years. Forty-five patients had a complication, for a rate of 16.7%. Five early patients had vertebral artery injuries, 1 of which was bilateral and fatal. No recent patients had vertebral artery injuries. Other complications did not result in neurologic morbidity. Review of all atlantoaxial fusions by the senior author (R.I.A.) revealed that the TAS fixation technique could be successfully applied in 86.7% of sides considered. The main reasons for inapplicability were anatomic (recognized on preoperative planning) in 77% and abandonment secondary to concern about possible vertebral artery injury on the first side attempted in 13.8%. CONCLUSION The placement of TASs is safe and effective for stabilizing the atlantoaxial articulation. Refinements in technique, such as 3-dimensional stereotactic workstation for trajectory planning, have reduced the rate of serious complications. Clinical outcomes are excellent, with nearly 100% of patients achieving stable bony union.

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