Brief anatomy of the knee:
The knee is a vulnerable joint that bears a great
deal of stress from everyday activities such as
lifting and kneeling, and from high-impact activities
such as jogging and aerobics.
The knee is formed by the following parts:
- tibia - shin bone or larger bone of
the lower leg.
- femur - thighbone or upper leg bone.
- patella - kneecap.
Each bone end is covered with a layer of cartilage
that absorbs shock and protects the knee. Basically,
the knee is two long leg bones held together by
muscles, ligaments, and tendons.
There are two groups of muscles involved in the
knee, including the quadriceps muscles (located
on the front of the thighs), which straighten
the legs, and the hamstring muscles (located on
the back of the thighs), which bend the leg at
the knee.
Tendons are tough cords of tissue that connect
muscles to bones. Ligaments are elastic bands
of tissue that connect bone to bone. Some ligaments
on the knee provide stability and protection of
the joints, while other ligaments limit forward
and backward movement of the tibia (shin bone).
What are some common knee problems?
Many knee problems are a result of the aging
process and continual wear and stress on the knee
joint (i.e., arthritis). Other knee problems are
a result of an injury or a sudden movement that
strains the knee. Common knee problems include
the following:
- sprained or strained knee ligaments and/or
muscles
A sprained or strained knee ligament or muscle
is usually caused by a blow to the knee or a
sudden twist of the knee. Symptoms often include
pain, swelling, and difficulty in walking.
- torn cartilage
Trauma to the knee can tear the menisci (pads
of connective tissue that act as shock absorbers
and also enhance stability). Cartilage tears
can often occur with sprains. Treatment may
involve wearing a brace during an activity to
protect the knee from further injury. Surgery
may be needed to repair the tear.
- tendonitis
Inflammation of the tendons may result from
overuse of a tendon during certain activities
such as running, jumping, or cycling. Tendonitis
of the patellar tendon is called jumper's knee.
This often occurs with sports such as basketball,
where the force of hitting the ground after
a jump strains the tendon.
- arthritis
Osteoarthritis is the most common type of
arthritis that affects the knee. Osteoarthritis
is a degenerative process where the cartilage
in the joint gradually wears away, and often
affects middle-age and older people. Osteoarthritis
may be caused by excess stress on the joint
such as repeated injury or being overweight.
Rheumatoid arthritis can also affect the knees
by causing the joint to become inflamed and
by destroying the knee cartilage. Rheumatoid
arthritis often affects persons at an earlier
age than osteoarthritis.
How are knee problems diagnosed?
In addition to a complete medical history and
physical examination, diagnostic procedures for
knee problems may include the following:
- x-ray - a diagnostic test which uses
invisible electromagnetic energy beams to produce
images of internal tissues, bones, and organs
onto film.
- magnetic resonance imaging (MRI) -
a diagnostic procedure that uses a combination
of large magnets, radiofrequencies, and a computer
to produce detailed images of organs and structures
within the body; can often determine damage
or disease in a surrounding ligament or muscle.
- computed tomography scan (Also called a
CT or CAT scan.) - a diagnostic imaging
procedure that uses a combination of x-rays
and computer technology to produce cross-sectional
images (often called slices), both horizontally
and vertically, of the body. A CT scan shows
detailed images of any part of the body, including
the bones, muscles, fat, and organs. CT scans
are more detailed than general x-rays.
- arthroscopy - a minimally-invasive
diagnostic and treatment procedure used for
conditions of a joint. This procedure uses a
small, lighted, optic tube (arthroscope) which
is inserted into the joint through a small incision
in the joint. Images of the inside of the joint
are projected onto a screen; used to evaluate
any degenerative and/or arthritic changes in
the joint; to detect bone diseases and tumors;
to determine the cause of bone pain and inflammation.
- radionuclide bone scan - a nuclear
imaging technique that uses a very small amount
of radioactive material, which is injected into
the patient's bloodstream to be detected by
a scanner. This test shows blood flow to the
bone and cell activity within the bone.
Treatment for knee problems:
Specific treatment for knee problems will be
determined by your physician based on:
- your age, overall health, and medical history
- extent of the disease, injury, or condition
- your tolerance for specific medications, procedures,
or therapies
- expectations for the course of the disease,
injury, or condition
- your opinion or preference
If initial treatment methods do not provide relief,
and x-rays show destruction of the joint, the
orthopaedist may recommend total joint replacement
for the knee.
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