 
Over the past twenty years, there has been a significant
increase in the use of cervical plates for single and multi-level anterior
cervical surgery. One of the goals of a cervical plate is to improve initial stability in
the post-operative period in order to decrease the need for wearing a
cervical collar and result in a faster return to normal activities. In
addition, anterior cervical plate fixation can potentially decrease the
complications of graft dislocation, end plate fracture, and late kyphotic
collapse.
The
design team for the ATLANTIS® Anterior Cervical Plate System, which
includes spine surgeons Dr. Volker Sonntag, Dr. Regis
Haid, and Dr. Stephen Papadopoulos, set out to create a comprehensive
instrumentation system that would incorporate all of the ideal features
of modern cervical plates in a single system. The features that are available
in the ATLANTIS® System include flexibility in construct choice,
an attached locking mechanism, and variability in screw placement.
The ability to choose between unicortical and/or bicortical
screw purchase allows the surgeon to tailor the amount of screw to cortex
fixation to the needs of the patient. In primary cases with appropriate
bone quality, a unicortical screw can be selected for ease of fixation
without having to penetrate the distal (far) cortex. In revision surgeries,
or situations where osteoporosis makes single cortex fixation less desirable,
surgeons have the flexibility of using a bicortical screw for additional
pull-out resistance.
Basics and Benefits
There are certain situations in anterior cervical surgery
where the pre-determined trajectory of the fixed angle screw may be undesirable.
The ATLANTIS® Anterior Cervical Plate System can address these
situations by allowing the surgeon to switch to a variable angle screw
that permits greater freedom in choosing the placement and trajectory
of the screw into the vertebral body. This need often arises in revision
surgeries where screw purchase may be compromised by existing screw holes
and more flexibility is needed in order to place a screw into solid bone.
Another common situation that may require the use of
a variable angle screw arises when a hemi-corpectomy is performed in order
to treat the underlying pathology. After the hemi-corpectomy has been
completed, the amount of bone available for screw purchase can be quite
small and a fixed angle screw with a 12 degree cephalad/caudal screw trajectory
with respect to the plate may violate the disc space above or below the
level of the surgery. In this instance, the variable angle screw allows
the surgeon to chose a trajectory that is less steep and ensures that
the screw is appropriately placed in the remainder of the vertebral body.
The third situation that often dictates the use of variable
angle screws involves the placement of screws into vertebral bodies at
the extremes of the cervical spine. Limited exposure of the inferior and
superior (top and bottom) of the cervical spine can make fixed angle screw
placement difficult because the proper positioning of the instrumentation
may be impaired by soft tissue and the physiologic limits to further retraction.
The variable angle screws permit a steeper trajectory so that the surgeon
is able to place a screw into the vertebral bodies at either end of the
cervical spine without having to adhere to the requirement for a 12-degree
cephalad/caudad trajectory with the fixed screws.
Click here to find a doctor who uses this technology.
It is important that you discuss the potential risks, complications, and benefits of the ATLANTIS® with your doctor prior to receiving treatment, and that you rely on your physician's judgment. Only your doctor can determine whether you are a suitable candidate for this treatment.
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