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Craniovertebral Junction Instability: A Review of Facts about Facets.

Goel A - Asian Spine J (2015)

Bottom Line: The facets of atlas and axis form the primary site of movements at the craniovertebral junction.All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint.Direct manipulation and fixation of the facets forms the basis of treatment for instability.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, King Edward Memorial Hospital and Seth Gordhandas Sunderdas Medical College, Mumbai, India.

ABSTRACT
Craniovertebral junction surgery involves an appropriate philosophical, biomechanical and anatomical understanding apart from high degree of technical skill and ability of controlling venous and arterial bleeding. The author presents his 30-year experience with treating complex craniovertebral junction instability related surgical issues. The facets of atlas and axis form the primary site of movements at the craniovertebral junction. All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint. Direct manipulation and fixation of the facets forms the basis of treatment for instability.

No MeSH data available.


Related in: MedlinePlus

Images of a 12-year-old male. (A) Computed tomography (CT) scan (sagittal view) with the head in flexed position shows severe atlantoaxial dislocation. There is os odontoideum. (B) CT scan with the head in extension shows reduction in the atlantoaxial dislocation. (C) T2-weighted magnetic resonance imaging shows severe cord compression. (D) Postoperative CT scan shows fixation with satisfactory alignment. (E) Lateral view of plain X-ray showing plate and screw fixation.
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Figure 1: Images of a 12-year-old male. (A) Computed tomography (CT) scan (sagittal view) with the head in flexed position shows severe atlantoaxial dislocation. There is os odontoideum. (B) CT scan with the head in extension shows reduction in the atlantoaxial dislocation. (C) T2-weighted magnetic resonance imaging shows severe cord compression. (D) Postoperative CT scan shows fixation with satisfactory alignment. (E) Lateral view of plain X-ray showing plate and screw fixation.

Mentions: Inclusion of the occipital bone in the fixation constructs became popular in the 1980's. The implants included loops and contoured metal rods. The fixation of the occipital end of the implant was done earlier with the help of wires and subsequently with the assistance of screws. However, as the biomechanical issues of the region were understood, the focus of craniovertebral junction stabilization techniques is now only on segmental atlantoaxial fixation. It may not be incorrect to state that all craniovertebral instability is equivalent to atlantoaxial instability. Occipitoatlantal instability is seen only in extreme trauma or sometimes in pediatric age patients and is generally related to syndromic affection of multiple joints. Craniovertebral junction stabilization is essentially equivalent to atlantoaxial stabilization. Direct atlantoaxial fixation in cases with basilar invagination is relatively a difficult technical surgery. However, if it is done satisfactorily and completely, it provides a segmental stabilization at the point of fulcrum of all movements. Inclusion of occipital bone in the fixation construct provides a suboptimal form of fixation, as it involves inclusion of a normal joint in the fixation assembly. Although inclusion of the occipital bone in the fixation construct is still popular, the technique is gradually but surely receiving less favor.


Craniovertebral Junction Instability: A Review of Facts about Facets.

Goel A - Asian Spine J (2015)

Images of a 12-year-old male. (A) Computed tomography (CT) scan (sagittal view) with the head in flexed position shows severe atlantoaxial dislocation. There is os odontoideum. (B) CT scan with the head in extension shows reduction in the atlantoaxial dislocation. (C) T2-weighted magnetic resonance imaging shows severe cord compression. (D) Postoperative CT scan shows fixation with satisfactory alignment. (E) Lateral view of plain X-ray showing plate and screw fixation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522459&req=5

Figure 1: Images of a 12-year-old male. (A) Computed tomography (CT) scan (sagittal view) with the head in flexed position shows severe atlantoaxial dislocation. There is os odontoideum. (B) CT scan with the head in extension shows reduction in the atlantoaxial dislocation. (C) T2-weighted magnetic resonance imaging shows severe cord compression. (D) Postoperative CT scan shows fixation with satisfactory alignment. (E) Lateral view of plain X-ray showing plate and screw fixation.
Mentions: Inclusion of the occipital bone in the fixation constructs became popular in the 1980's. The implants included loops and contoured metal rods. The fixation of the occipital end of the implant was done earlier with the help of wires and subsequently with the assistance of screws. However, as the biomechanical issues of the region were understood, the focus of craniovertebral junction stabilization techniques is now only on segmental atlantoaxial fixation. It may not be incorrect to state that all craniovertebral instability is equivalent to atlantoaxial instability. Occipitoatlantal instability is seen only in extreme trauma or sometimes in pediatric age patients and is generally related to syndromic affection of multiple joints. Craniovertebral junction stabilization is essentially equivalent to atlantoaxial stabilization. Direct atlantoaxial fixation in cases with basilar invagination is relatively a difficult technical surgery. However, if it is done satisfactorily and completely, it provides a segmental stabilization at the point of fulcrum of all movements. Inclusion of occipital bone in the fixation construct provides a suboptimal form of fixation, as it involves inclusion of a normal joint in the fixation assembly. Although inclusion of the occipital bone in the fixation construct is still popular, the technique is gradually but surely receiving less favor.

Bottom Line: The facets of atlas and axis form the primary site of movements at the craniovertebral junction.All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint.Direct manipulation and fixation of the facets forms the basis of treatment for instability.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, King Edward Memorial Hospital and Seth Gordhandas Sunderdas Medical College, Mumbai, India.

ABSTRACT
Craniovertebral junction surgery involves an appropriate philosophical, biomechanical and anatomical understanding apart from high degree of technical skill and ability of controlling venous and arterial bleeding. The author presents his 30-year experience with treating complex craniovertebral junction instability related surgical issues. The facets of atlas and axis form the primary site of movements at the craniovertebral junction. All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint. Direct manipulation and fixation of the facets forms the basis of treatment for instability.

No MeSH data available.


Related in: MedlinePlus