Introduction
The use of instrumentation - specially designed hooks, rods, and screws - has
revolutionized spinal surgery in the last 25 years. As these instrumentation
systems continue to develop and progress, millions of patients with a wide variety
of serious spinal conditions are finding the help and relief they have been
searching for.
If you are in need of spinal surgery that involves the use of instrumentation,
surgeons now have a tool that can help make this type of surgery even easier.
Medtronic Sofamor Danek's CD HORIZON® M8 Multi Axial Screws are the latest addition
to a whole system of instruments designed to stabilize areas of the spine. These
specially designed screws facilitate lining up the rods with the pedicle screws.
Easier placement means less time spent in surgery for the patient, more successful
outcomes, and less recovery time.
When Is Instrumentation Used?
Even though most spinal conditions can be treated using non-surgical methods,
if the spine becomes too unstable, pain is unresolvable, or the patient experiences
neurological dysfunction, surgery may be the best answer.
Instrumentation systems such as hooks, rods, and screws are used to surgically
stabilize spinal trauma and deformity. Often, these implants are used together
during a procedure - for example, multiaxial screws help with lining up many
of the pedicle screws with the rods. Multiaxial screws cut down, to some extent,
on the need for rod contouring, they make it easier to engage rods into pedicle
screws and they, as stated, cut down on the stress on the bone-screw interface.
There are a variety of spinal conditions that can cause serious spinal instability.
These include:
(1) Degenerative spondylolisthesis - a spinal a disorder that causes the forward
motion, or slip, of one vertebral body over the one below.
(2) Spinal fracture - breaks in the bones of the spine, such as the vertebrae.
(3) Scoliosis - curvature of the spine.
(4) Kyphosis - a progressive spinal disorder also called humpback or hunchback.
(5) Spinal tumor - cancerous growths on the spine.
If these spinal conditions progress to a point that the spine becomes seriously
unstable, instrumentation surgery is performed to add strength and stability,
return functionality, and decrease pain.
Screws and Rods - Adding Strength to the Spine
The pedicle is part of the vertebral column that connects the front of the
spine to the back of the spine. There is one pedicle on each side of each vertebra.
Placing a screw into the pedicle bone of the vertebral body is done to fixate
and stabilized the spine. If necessary, pedicle screws can be placed at several
levels of the spine; a rod is then used to connect them together, giving the
spine considerable extra strength.
How Do These Screws Work?
Many spinal surgeons use the CD HORIZON® M8 Multi Axial Screws (pictured below) because
they can be angled 28° in any direction, making it easier for the surgeon to
implant hooks, rods or other instrumentation. They also have break-off heads,
a feature that helps the surgeon determine when the screws have been successfully
secured. Available in medical grade steel and titanium, these "low-profile"
screws are designed to fit most body sizes with minimal interference with other
parts of the anatomy. In addition, the M8 Multi Axial Screws include a buttress
thread design, a single locking mechanism (break off set screws), and top loading
mechanism to facilitate rod placement and reduction.
Knowledge is a Powerful Healer
If you are in need of spinal surgery, your surgeon will discuss with you in
detail how the procedure will be done. He or she will determine which instrumentation
system is best for your particular condition. While it is not necessary to understand
all of the technical aspects of how these instrumentation systems are designed
and used, many patients find it helpful and comforting to learn a little about
the system used in their procedure. Understanding as much as you can about your
condition and your surgery can help you as you proceed down the road to recovery.
