The Flex Fixed Knee replacement is the
first knee specifically designed to
safely accommodate flexibility of up
to 155 degrees. Many activities of daily
living require good range of motion,
such as climbing stairs (75-140 degrees)
and sitting in a chair (90-130 degrees).
Hobbies such as gardening and golfing
or activities such as kneeling for prayer
and sitting cross-legged can demand
an even greater degree of bending. Generally,
knee replacements have been designed
to accommodate flexibility up to 125
is the benefit of the Flex Fixed Knee?
Flex Fixed Knee is specifically designed
to safely accommodate up to 155 degrees
of flexion in patients who had this
ability before surgery. This means that
with appropriate rehabilitation a patient
can resume an active lifestyle after
total knee replacement – deeply bending
the knee for recreational, religious
and other day-to-day activities. Patients
today want to continue their previous
lifestyles – even after total knee replacement.
The Flex Fixed Knee may be an option
for many patients to help them achieve
Flex Knee Replacement - Surgical Procedure
knee is the hinge joint consisting of
three bones. The upper part of the hinge
is at the end of the upper leg bone
(femur), and the lower part of the hinge
is at the top of the lower leg bone
(tibia). When the knee is bent, the
end of the femur rolls and slides on
top of the tibia. A third bone, the
kneecap (patella), glides over the front
and end of the femur.
a healthy knee joint, the surfaces of
these bones are very smooth and covered
with a tough protective tissue called
cartilage. Osteoarthritis causes damage
to the bone surfaces and cartilage where
the three bones meet and rub together.
These damaged surfaces can eventually
become painful. There are several ways
to treat the pain caused by osteoarthritis.
One way is a total knee replacement
surgery. The decision to have total
knee replacement surgery should be made
very carefully after consulting your
doctor and learning as much as you can
about the knee joint, osteoarthritis,
and the surgery.
some cases, the Flex Fixed Knee may
be an option for total knee replacement.
The basic surgical procedure for the
Flex Fixed Knee is the same as for any
other total knee replacement. In total
knee replacement surgery, the bone surfaces
and cartilage that have been damaged
by osteoarthritis are removed and replaced
with artificial surfaces made of metal
and a plastic material. We call these
artificial surfaces "implants,"
to the Joint
patient is first taken into the operating
room and given anesthesia. After the
anesthesia has taken effect, the skin
around the knee is thoroughly scrubbed
with an antiseptic liquid. The knee
is flexed about 90 degrees and the lower
portion of the leg, including the foot,
is placed in a special device to securely
hold it in place during the surgery.
Usually a tourniquet is then applied
to the upper portion of the leg to help
slow the flow of blood during the surgery.
is then made that typically extends
from just above the knee to just below
the knee. The incision is gradually
made deeper through muscle and other
tissue until the bone surfaces are exposed.
the Damaged Bone Surfaces
damaged bone surfaces and cartilage
are then removed by the surgeon. Precision
instruments and guides are used to help
make sure the cuts are made at the correct
angles so the bones will align properly
after the new surfaces (implants) are
attached. Small amounts of the bone
surface are removed from the front,
end and back of the femur. This shapes
the bone so the implants will fit properly.
The amount of bone that is removed depends
on the amount of bone that has been
damaged by the osteoarthritis. A small
portion of the top surface of the tibia
is also removed, making the end of the
bone flat. The back surface of the patella
(kneecap) is also removed.
implant is attached to each of the three
bones. These implants are designed so
that the knee joint will move in a way
that is very similar to the way the
joint moved when it was healthy. The
implants are attached using a special
kind of cement for bones.The implant
that fits over the end of the femur
is made of metal. Its surface is rounded
and very smooth, covering the front
and back of the bone as well as the
end. The implant that fits over the
top of the tibia usually consists of
two parts. A metal baseplate fits over
the part of the bone that was cut flat.
A durable plastic insert is then attached
to the baseplate to serve as an articulating
surface between the baseplate and the
metal implant that covers the end of
the femur. The implant that covers the
back of the patella is also made of
a durable plastic. Artificial
knee implants come in many designs.
The surgeon will choose the implant
design that best meets the patient's
Implants After Attachment
If necessary, the surgeon may adjust
the ligaments that surround the knee
to achieve the best possible knee function.
of the implants are in place and the
ligaments are properly adjusted, the
surgeon sews the layers of tissue back
into their proper position. A plastic
tube may be inserted into the wound
to allow liquids to drain from the site
during the first few hours after surgery.
The edges of the skin are then sewn
together, and the knee is wrapped in
a sterile bandage. The patient is then
taken to the recovery room.
to "Orthopaedics Surgery"