More people in the United States visit an orthopedic surgeon because of knee problems than for any other complaint. Knee pain affects approximately one quarter of adults, and its prevalence has increased almost 65% over the past 20 years. Pain in the knees accounts for nearly four million primary care visits a year.
Down the road, many of these folks seeking help will end up with osteoarthritis in their damaged knee joints, facing knee replacements and other surgeries. But this doesn't have to happen. A little prevention now can save considerable pain later.
How do knees get injured?
Osteoarthritis occurs when cartilage in the joint gradually wears away. The condition may result from a deformity in the joint, repeated injury, or the stress of excess body weight, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). This form of arthritis most often affects middle-aged and older people, but knee injuries as a teenager or young adult can make you more likely to develop the condition later in life.
The knee is the largest joint in the body and one of the most easily damaged. Ligament sprains and cartilage tears are the most common knee injuries. Ligaments help control motion by connecting bones and bracing joints against abnormal impact. Cartilage cushions your knee and helps absorb shock when the joint is in motion.
The anterior cruciate ligament (ACL) in front of the knee and the medial collateral ligament (MCL) connecting the tibia and femur bones inside the knee are common injury sites; less common is damaging the posterior cruciate ligament (PCL) behind the knee.
Many ACL tears are caused by quickly changing direction, twisting, slowing down when running, or landing from a jump, according to the orthopedic surgeons' organization. Skiers and people who play basketball, volleyball, soccer, or football are susceptible to this kind of injury. Often people will feel a "pop" in their knee at the time of the injury, and they may have trouble with knee stability afterward. They may report that their knee seems to be "giving way" underneath them.
MCL injuries are often caused by a blow to the knee and are common among football players. PCL tears or strains are also often the result of contact sports. A simple misstep or twist can tear knee cartilage.
Inflammatory disease can also cause knee problems. Certain autoimmune diseases like rheumatoid arthritis and lupus can damage the knee.
Although musculoskeletal injuries are usually not gender specific, the American Academy of Orthopaedic Surgeons notes that women appear to be more susceptible to ACL injuries than men. Women basketball players are twice as likely as their male counterparts to experience this kind of ligament injury. Women soccer players are four times as likely as men to experience an ACL tear.
Surgeons note that women tend not to bend their knees as much as men when turning, pivoting, or landing from a jump. Learning to crouch and bend at the knees and hips when playing sports could reduce pressure on knee ligaments, the group advises.
Preventing knee damage
NIAMS has this advice for anyone, young or old, on how to avoid knee injuries:
- Before exercising, warm up by walking, riding a stationary bicycle, or doing some other low-impact activity. Then stretch the muscles in front of the thigh (quadriceps) and the back of the thigh (hamstrings) to reduce tension on your tendons and relieve pressure on your knee.
- Strengthen your leg muscles to help maintain stability in your knees. You could try walking up stairs or doing a supervised workout with weights.
- Avoid sudden changes in exercise intensity. Increase or decrease the force and duration gradually.
- Wear shoes that fit properly and are in good enough condition to help maintain balance and leg alignment when you walk or run. Knee problems can be caused by flat or overpronated feet (feet that roll inward). Special shoe inserts (orthotics) custom-molded to the shape of your foot can help.
- Maintain a healthy weight. If you're overweight, lose those extra pounds. Being overweight or obese stresses joints and increases the risk of degenerative arthritis.
- If you ride a bicycle, make sure that the seat is high enough so that pedaling won't put too much pressure on your knees. Ask the people at your local bike shop if you're unsure how high it should be.
Recognizing and treating knee injuries
If you injure a knee ligament, you may hear a popping noise or feel your knee give out from under you. You may feel excruciating pain and be unable to walk. But after some types of knee injuries, you may not feel the pain right away. Within two to 12 hours, you'll probably experience pain and swelling.
It's important to get treated as soon as possible. For minor knee injuries, doctors often recommend following the RICE method of rest, ice, compression, and elevation for the first 24 to 72 hours after the injury. Try to take it easy immediately after you injure yourself. Ice your knee for 15 minutes every two hours to reduce inflammation and pain; anti-inflammatory medications such as ibuprofen can be very helpful as well. Wrap the affected area with an elastic bandage to provide compression and reduce swelling, and elevate your leg. This also will help take down swelling.
Taking care of your knees now will go a long way toward avoiding problems that could take you out of the game for good.
American Academy of Orthopaedic Surgeons.
"Knee Pain in Adults and Adolescents: The Initial Evaluation," American Family Physician.
National Institute of Arthritis and Musculoskeletal and Skin Diseases, "Questions and Answers About Knee Problems," booklet.
Australian Physiotherapy Association, "Knee Injuries," Physio-net.com.
American Academy of Orthopaedic Surgeons. Knee Ligament Injuries.
American Academy of Orthopaedic Surgeron. Public Service Announcement: Joint Pain Knee.