Ligament Injuries

The volleyball match has been going
on for over an hour. Both teams have been trading
points and side-outs. The ball is set high outside so
that the big outside hitter can put the ball away.
She comes in hard, plants, leaps into the air and
smashes the ball down the line in a twisting motion.
As she lands on her right leg, a POP is heard and
down she goes. What has just happened is
occurring more and more often in athletics, the
athlete has just torn the anterior cruciate ligament
(ACL). In this paper I will describe ACL, how it
is injured and diagnosed, how it be repaired and
what is being done to prevent ACL injuries. The
Anterior Cruciate Ligament (ACL) is one of the
two cruciate ligaments of the knee, the other being
the Posterior Cruciate Ligament (PCL). These
ligaments are the stabilizers of the knee. The ACL
is a strip of fibery tissue, which is located deep
inside the knee joint. It runs from the posterior
side of the femur (thigh bone) to the anterior side
of the tibia (shin bone) deep inside of the knee.
The ligament is a broad, thick cord the size of a
person\'s index finger. It has long collagen strands
woven together in a fashion that permits forces of
up to 500 pounds to be exerted. The function of
the ACL is to prevent the tibia from moving in
front of the knee and femur. The ACL also
prevents hyperextension (or extreme stretching of
the knee backward) and helps to prevent rotation
of the tibia. The amount of knee ligament injuries
have been on the rise in recent years. Over the last
15 years, ankle sprains have decreased by 86%
and tibia fractures by 88%, but knee ligament
injuries have increased by 172%. The injury
usually occurs in either a slow twisting fall, a
sudden hyperextension, or a sudden hyperflexion
as when landing from jumping. When the injury
occurs the athlete usually hears a "pop" and they
will have immediate swelling of the knee. When
the person tries to put weight on the leg it will feel
like the knee isn\'t underneath the athlete. With
most injuries the type of movement will help to
determine the injury: "I twisted to the right." etc.
When ACL injuries occur there is a "popping"
sound at the time of injury and swelling within six
hours. An experienced clinician can diagnose an
ACL tear with relative accuracy by a manual
examination. X-ray examination and Magnetic
Resonance Imaging (MRI) is also used in
diagnosing ACL injuries. The knee joint will be
instable and the athlete will have joint pain on the
inner (medial) side of the knee. Doctors or trainers
can use three different types of physical
examinations: Lachman\'s test, Anterior drawer test
and Pivot shift test of MacIntosh. Lachman\'s test
is performed by having the athlete lie on his/her
back, then passively flexing the knee of the athlete
to between 20 degrees and 30 degrees. Make
sure that the hamstring is relaxed or it can produce
a false test result. Holding the lower part of the
athlete\'s thigh in one hand and the upper part of
the athlete\'s calf in the other, slowly pull the tibia
forward. Increased looseness in the knee joint is
indicative of an ACL injury. During the Anterior
drawer test the athlete lies on his/her back with the
knee bent to 90 degrees and the foot resting on
the table. Stabilizing the foot either by sitting on it
or having someone else hold it down, the doctor
will place his/her hands around the upper part of
the calf with thumbs on the end of the thigh bone
(tibal condyles), slowly appling pressure on the
posterior side of the proximal tibia. Any looseness
in the joint could indicate ACL injury. The Pivot
shift test of MacIntosh is done by having the
athlete lay on his/her back. The foot of the injured
side is lifted with the leg straight and the foot
turned inward. Pressure is applied to the outside
of the knee while the knee joint is slowly bent. An
ACL injury is detected if the tibia moves out of
joint at 30-40 degrees or if a clunk is felt. One
should note that this test can be very painful for the
athlete. When an athlete has injured his/her ACL
the initial treatment involves splinting the knee, ice
treatment to help reduce swelling, elevation of the
joint (just above the heart) and administration of
anti-inflammatory drugs. The athlete also needs to
limit physical activity. A non-athletic person can
live with the injury using rehabilitation and bracing.
When the ACL is injured the guide wire of the
knee is gone, creating instability. Without the
stabilizing actions of the ligament, there is
increased wear on