What Causes Knee Pain?
Osteoarthritis is the leading cause of knee pain in the United States and
the most common form of arthritis. It occurs when the joint cartilage
and the bone underneath wears down over time. Studies estimate that over
half of people will develop knee osteoarthritis over their lifetime.
First image: Healthy knee with evenly spaced gaps (no osteoarthritis).
Second image: Knee with inside compartment wear and tear (medial osteoarthritis).
Third image: Knee with full bone-on-bone wear and tear (medial and lateral
A knee with osteoarthritis is not able to bend and function as well as
a healthy knee. When osteoarthritis sets in the cartilage - a smooth and
slippery tissue that covers and cushions the ends of bones - becomes frayed
and wears away. Over time the progression of osteoarthritis can lead to
increased pain and reduced mobility.
Osteoarthritis symptoms often include pain and stiffness. This is commonly
described as an aching pain, like pain experienced after a long walk.
Symptoms may be more noticeable in the morning or after a long period
of rest. Osteoarthritis, known as "wear and tear" arthritis,
often affects people in their middle-ages and beyond.
How Does Osteoarthritis Affect Your Knee?
Osteoarthritis develops slowly over many years, often causing pain that
makes movement more difficult. If the cartilage wears completely away,
bone-on-bone contact can occur. To make up for the lost cartilage when
this occurs, the damaged bones may grow outward and develop painful deformities.
The pain caused by osteoarthritis can range from mild to significant.
What Are The Leading Causes of Knee Osteoarthritis?
Age. Osteoarthritis typically affects people in their middle ages and beyond
as cartilage loses its ability to heal or regenerate. An estimated 1 in
2 people will develop knee osteoarthritis by age 85.
Weight. The more you weigh, the more stress is placed on your knee joint. An
estimated 2 in 3 people who are obese will develop knee osteoarthritis
in their lifetime.
Heredity. Inherited traits such as bow leggedness, knock-kneed and double-jointed
can put you at greater risk for osteoarthritis.
Injury. A knee injury that occurred earlier in life - such as in sports or at
work - can eventually lead to osteoarthritis.
Repetitive stress. Occupation related movements, such as kneeling, heavy lifting and walking
can lead to stress injuries in the knee and can make it more likely for
osteoarthritis to develop.
Gender. Women are more likely than men to experience knee osteoarthritis. However,
over 30 million American men and women collectively suffer from the disease.
Other illnesses. If you have had other problems with your knee, such as a knee infection
or gout, the risk of osteoarthritis may increase.
Diagnosis and Treatment of Osteoarthritis
If you have knee pain and believe you have knee osteoarthritis, it is best
to consult with a physician to determine what can be done. When you meet
with one of our physicians, you will likely be asked when the symptoms
started, whether they have gotten worse over time, and how you feel doing
certain activities. The physician will likely ask about you and your family’s
medical history. It is also common to perform a physical examination to
check your knee reflexes and mobility.
X-rays will be ordered to confirm that you have osteoarthritis. X-rays
can show how much osteoarthritis wear has occurred and whether the osteoarthritis
is located in one area of the knee or if it has progressed to multiple areas.
Once it is determined you have osteoarthritis, there are many treatment
options that can help manage the pain and keep you active. Here at Shasta
Regional Medical Center, our physicians are dedicated to working closely
with you to develop a personal treatment plan designed to help relieve
your knee pain and stiffness.
1. Centers for Disease Control and Prevention, Arthritis-Related Statistics