What is the Anterior Cruciate
Ligament (ACL)?
The anterior cruciate ligament (ACL)
is the central stabilizing ligament of the knee.
Running through the knee from the front of the tibia (shin bone) to the
back of the femur (thigh bone) it assists proper movement of the joint and
prevents abnormal slippage of the bones. Abnormal
slippage can create an unstable knee that "gives way" during activity.
How is the ACL injured?
While the ligament can be
injured with a direct blow to the knee, it is more common to tear the ligament
when pivoting or twisting on a planted food or by hyper extending the knee.
How do I know my ACL is torn?
Usually, a tear to the ACL
results in sudden pain, giving way of the knee, or a combination of both.
Many patient report having heard a "pop" when they injured
their knee. The knee usually
swells within 1-3 hours of the injury. A
doctor can examine the knee and is usually able to identify any ligaments that
are injured. The knee will feel loose and/or you will have muscle guarding
during the examination.
Do I need x-rays, MRI's or
any other tests?
A set of x-rays is usually
ordered to make sure that there are no broken bones in the knee.
MRI's can be helpful, but are not always needed when the doctor knows
what is wrong just from examining you. MRI's
are obtained primarily to assess the extent of the damage to other structures
including the menisci, joint surfaces and bone.
Is there usually other damage
to the knee when the ACL is torn?
Other ligaments in the knee can
be injured at the same time as the ACL. These
may need to be repaired, but many times heal adequately without surgery.
The most common injury that
occurs with the ACL tear is a meniscus tear.
Some meniscus tears can be repaired
and some can be trimmed back so that the torn edges are smooth. If the
meniscus can be repaired, it is usually done at the time of the ACL surgery.
Another common injury that can
occur with an ACL tear is damage to the cartilage on the joint surface.
Damage to these surfaces is very serious and in some cases is the worst
part of the injury. It may require
more complex surgery which is usually done at the time of the ACL surgery.
Does a torn ACL have to be
fixed with surgery?
The ACL cannot heal on its own,
but not all tears of the ACL need to be fixed.
This depends on age and your activity level. People under 40 years of age should have their ACL
reconstructed to prevent arthritis. People
participating in activities where they plant their feet and twist or cut are
susceptible to having an unstable knee and may be better off with surgery.
People with strenuous jobs may also need surgery.
People who are unwilling or unable to modify their activities and desire
an unrestricted lifestyle are encouraged to consider the surgery to have the
best chance of returning to their previous lifestyle.
Advances in arthroscopic surgery and an aggressive rehabilitation program
contribute to an accelerated recovery for patients with ACL injuries.
On the other hand, people who
lead a more sedentary lifestyle may be able to get by with exercise and a brace.
However, even someone with a sedentary lifestyle may experience giving
way with simple activities such as climbing or descending stairs or stepping off
a curb. In these cases surgery is needed to restore normal every day
activities and to prevent further damage to the knee.
If I don't have my ACL fixed
am I likely to hurt my knee again or get arthritis?
Even if the knee joint does not
become unstable (give way) it will still be loose after an ACL injury.
This leads to damage in other supporting structures, such as the medial
and lateral collateral ligaments and the cushion pads called meniscus
cartilages. In someone with a
recent ACL injury, the risk of associated meniscus damage may be 30 to 40
percent. In someone who has had an
ACL injury that has been present for years and who may have buckling episodes,
the risk of associated meniscus damage is 90 percent. ACL and meniscus injury
may contribute to the early onset of arthritis in your knee.
How is the ACL fixed?
The ACL is reconstructed with
arthroscopic techniques. The
arthroscope is a fiber optic instrument (narrower than a pen), which is put into
the joint through small incisions. A
camera is attached to the arthroscope and the image is viewed on a TV monitor.
The arthroscope allows the surgeon to fully evaluate the entire knee
joint. Small instruments ranging from 3-9 millimeters in size are
inserted through additional incisions so that the surgeon can feel the various
joint structures, diagnose the injury, and then repair, reconstruct or remove
the damaged structure.
In ACL reconstruction a
replacement graft is precisely positioned in the joint at the site of the former
ACL and then fixed to the thigh and lower leg bones with screws.
There are currently several options for replacement grafts and screws.
Choices for the type of replacement graft include autograft (using your
own tissue), allograft (donor tissue) and synthetic (artificial) grafts.
Choices for the types of screws include inert metal screws and
bio-absorbable screws.
Autografts can come from
your patellar tendon, quadriceps tendon or the hamstring tendons.
The graft choice to be used is determined by you and your surgeon.
All of these graft options offer a strong graft, secure fixation and
excellent long-term results. The
results show that people are able to return to their activities with few
complications. Since the graft
comes from your own body there is no chance of infectious disease transmission
or rejection.
Allografts are donor
tissues taken from tissue banks. They
also are strong grafts with excellent long-term results.
Because the surgeon is not taking the tissue from your body, the surgical
time and operative pain are less. This
allows for easier rehabilitation in the early post-operative stages. Although
there is a risk of infectious disease, donor tissue is received only from a
reliable tissue bank. The tissue is rigorously screened and treated to prevent the
spread of infectious disease. The
risk of contracting infectious disease from an allograft is very small (less
than one in eight million). Although
rejection of the graft is possible, the risk of this is extremely low because
the tissue is not living material.
Synthetic grafts are
available for use in certain situations, but most are experimental and do not
work as well as allografts and autografts.
Regardless of the graft material
chosen, the most important aspect of surgery is that the ligament graft is
placed and secured precisely. Accurate
graft placement is essential for a good result and secure graft placement
permits early, more aggressive rehabilitation after surgery.
What are some of the possible
complications?
While complications are not
common, all surgery has associated risks. Possible
complications include excessive stiffness after the surgery or pain in the knee
or under the kneecap. Your
rehabilitation after surgery is specifically designed to address these issues.
Other complications can arise from infection of the wounds, phlebitis,
bleeding into the knee, and nerve injury.
What do I need to do to
prepare for surgery?
Our staff will work with you to
set up the surgery through your insurance company and will instruct you in
matters that you will need to take care of concerning your insurance paperwork.
Prior to surgery you may be
asked to perform some exercises at home or with a physical therapist to prepare
for surgery. These exercises
prepare the knee by decreasing the swelling, increasing the motion and
maximizing the strength of your leg.
What type of anesthesia is
used?
Spinal, epidural or general
anesthesia can be used. Except for
when general anesthesia is used, the patient can stay awake and watch the
procedure on the TV monitor. An
anesthetist is always present if there is a need for further sedation or pain
control. The morning of
surgery, an anesthetist will discuss with you the various options and answer
your questions.
Because our surgeons are
extremely experienced, the operation can be performed rather quickly.
The shorter surgical time decreases the amount of anesthesia and limits
side effects from the anesthesia.
How long will I be in the
hospital?
Most people are able to have
surgery and go home the same day. Occasionally, a night in the hospital is
needed. How long you stay will
depend on several factors including your age, health status, other damage in the
knee, and the side effects of anesthesia.
What happens the day of
surgery?
The day before surgery you will
be told what time to report to the hospital the next day.
It is very important to arrive on time.
You will be admitted to the hospital and taken to a pre-operative area
where you will be prepared for your surgery and then taken to the operating
room.
Note:
You may not eat or drink anything after midnight the night before your
surgery. If you must take medicine
then you will be permitted to do so with just a sip of water.
After the operation, you will be
taken to the recovery room to be monitored.
Here the staff will check that the effects of the anesthesia are wearing
off properly and they will provide you with medication for any pain you are
having. If you are going home the
same day, you will be given specific instructions to follow at home and
discharged after you have adequately recovered.
If you have to remain overnight, you will be taken to your room when you
are ready.
How should I care for my knee
after surgery?
Prior to your discharge from the hospital you will be given specific
instructions on how to care for your knee.
It is important to follow these instructions.
In general, you can expect the following:
Diet:
Resume your regular diet as soon as possible.
Medication:
You will be given a prescription for pain medication and an
anti-inflammatory medication. Follow the directions from your pharmacy.
Bandage:
You will have an elastic bandage from your foot to your thigh.
There will be bulky dressings under the elastic wrap.
Keep these on for two to three days after your surgery as instructed.
Under these dressings you will have several small incisions with
stitches. You may cover these with
bandages after you remove the original dressing.
Brace:
A post-operative brace is worn when walking for six weeks after
surgery. A sports brace is then
provided and recommended for pivoting sports.
Bathing:
You will be able to shower within two to three days following surgery.
Do not soak your operated leg in a tub or whirlpool for at least three
weeks after surgery. The incisions
are not fully closed and soaking the leg would increase the risk of infection.
Once you have showered you should put the brace back on prior to leaving
the shower.
Ice: Use ice over the knee.
It is best to apply ice for 20 minutes at a time, usually three to four
times per day. During the first two
days after surgery, the heavy bandages may make it difficult for ice to
penetrate. Do not leave the ice
directly on your skin for extended periods as this may cause frostbite.
DO NOT put heat on your knee.
Elevation:
Keeping your leg elevated above the level of your heart will help with
swelling and discomfort. DO NOT put a pillow directly under your knee as this
encourages the knee to stay in a bent position.
Instead, place the pillow under the calf and foot.
Continuous Passive Motion (CPM):
To prevent difficulty moving the knee after surgery, a CPM Machine gently
promotes early postoperative motion. This
early movement of the knee also decreases swelling in the operated area.
In most cases, a CPM will be provided to you before you are released from
the hospital.
Crutches:
Crutches are required for walking at first.
Most patients use crutches for the first 7-14 days.
Follow-Up Office Visit:
You will be instructed to follow-up at our office one and one-half weeks
after your surgery. At this time, your stitches are removed, and your surgery is
reviewed. You will be instructed on
making further follow-up appointments at this time.
Exercise:
You may be taught some exercises to do initially after surgery.
After 1-½ weeks you are given a prescription for formal rehabilitation
to do with a physical therapist.
Return to work or school:
Most people are able to return to their jobs or school within 5-10
days. The exception to this is for
people who have strenuous jobs that require them to be on their feet a lot,
lifting objects, climbing or driving.
Driving:
You should be able to drive within weeks after surgery.
However, you should be aware that there might be laws pertaining to use
of your car in the early postoperative period.
If you are in a car accident and you knee is in a brace due to surgery,
there may be legal implications. Also,
you should not drive while you are taking narcotic analgesics.
What will rehabilitation
involve?
Rehabilitation begins the day after surgery.
As the tissues heal, you will be permitted to do more and more
activities. You will probably begin
walking immediately after surgery with the postoperative brace. Your
rehabilitation will be based on guidelines we have developed.
In general we use an accelerated protocol, which is based on several
goals: 1) early motion 2) early
weight bearing and 3) regaining control of the leg muscles as soon as possible.
Note that an accelerated program DOES NOT mean how soon you may
return to activities. You will
start out with very specific exercises and will be permitted to do more as you
recover.
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