Overview

Most people have had a minor knee problem at some time. Most of the time our body movements don't cause problems. But sometimes symptoms develop from everyday wear and tear, overuse, or injury. Knee problems and injuries most often occur during sports or recreational activities, work-related tasks, or home projects.

The upper and lower bones of the knee are separated by two discs (menisci). The upper leg bone (femur) and the lower leg bones (tibia and fibula) are connected by ligaments, tendons, and muscles. The surface of the bones inside the knee joint is covered by articular cartilage. It absorbs shock and provides a smooth, gliding surface for joint movement.

Knee problems are often caused by an injury to one or more of these parts of the knee. But they may be caused by things other than injuries. Some people are more likely to have knee problems than others. Many jobs, sports and activities, getting older, or having a disease such as osteoporosis or arthritis increase your chances of having problems with your knees.

Sudden (acute) injuries

Injuries are the most common cause of knee problems. Sudden (acute) injuries may be caused by a direct blow to the knee. Or they may be caused by abnormal twisting, bending the knee, or falling on the knee. Pain, bruising, or swelling may be severe and occur within minutes of the injury. Nerves or blood vessels may be pinched or damaged during the injury. The knee or lower leg may feel numb, weak, or cold. It may tingle or look pale or blue. Acute injuries include:

• Sprains, strains, or other injuries to the ligaments and tendons that connect and support the kneecap.
• A tear in the rubbery cushions of the knee joint (meniscus).
• A torn ligament, such as the anterior cruciate ligament (ACL). The medial collateral ligament (MCL) is the most often injured ligament of the knee.
• Breaks (fracture) of the kneecap, lower portion of the femur, or upper part of the tibia or fibula. Knee fractures are most often caused by abnormal force. Examples include falling on the knee, a severe twisting motion, severe force that bends the knee, and the knee forcefully hitting an object.
• Kneecap dislocation. This type of injury occurs more often in active teens and young adults.
• Pieces of bone or tissue (loose bodies) from a fracture or dislocation. They may get caught in the joint and interfere with movement.
• Knee joint dislocation. This is a rare injury that requires great force. It's a serious injury. It requires medical care right away.

Overuse injuries

Overuse injuries occur with repetitive activities or repeated or prolonged pressure on the knee. Knees can get irritated and inflamed when you climb stairs, ride a bike, jog, or jump, putting stress on your joints and other tissues. Overuse injuries include:

• Inflammation of the small sacs of fluid that cushion and lubricate the knee (bursitis).
• Inflammation of the tendons (tendinitis) or small tears in the tendons (tendinosis).
• Thickening or folding of the knee ligaments (plica syndrome).
• Pain in the front of the knee from overuse, injury, excess weight, or problems in the kneecap (patellofemoral pain syndrome).
• Irritation and inflammation of the band of fibrous tissue that runs down the outside of the thigh (iliotibial band syndrome).

Conditions that may cause knee problems

Problems not directly related to an injury or overuse may occur in or around the knee.

• Arthritis, especially osteoarthritis (degenerative joint disease). This may cause knee pain. It often occurs at the site of a previous injury.
• Osgood-Schlatter disease. This causes pain, swelling, and tenderness in the front of the knee below the kneecap.
• A popliteal (or Baker's) cyst. This causes swelling in the back of the knee.
• Infection in the skin (cellulitis), joint (infectious arthritis), bone (osteomyelitis), or bursa (septic bursitis). This can cause pain and decreased knee movement.
• A problem elsewhere in the body. Things like a pinched nerve or a problem in the hip can sometimes cause knee pain.
• Osteochondritis dissecans. This causes pain and decreased movement when a piece of bone or cartilage (or both) inside the knee joint loses blood supply and dies.

Treatment

Treatment for a knee problem or injury may include first aid, rest, bracing, physical therapy, and medicine. In some cases, surgery is needed. Treatment depends on:

• The location and type of injury, and how bad it is.
• Your age, health condition, and activity level (such as work, sports, or hobbies).

Self-Care

Try the following tips to help relieve knee pain, swelling, and stiffness.

• Rest.

  It's important to rest and protect the affected area. Stop, change, or take a break from any activity that may be causing your pain or soreness.

  When you rest, place a small pillow under your knee.

• Use ice.

  Put ice or a cold pack on your knee for 10 to 20 minutes at a time. Try to do this every 1 to 2 hours for the next 3 days (when you are awake).

• Wrap the affected area.

  Compression, or wrapping the area with an elastic bandage (such as an Ace wrap), will help reduce swelling.

  • Don't wrap it too tightly, because that can cause more swelling below the affected area. Loosen the bandage if it gets too tight. Signs that the bandage is too tight include numbness, tingling, increased pain, coolness, and swelling in the area below the bandage.
  • Don't expect the bandage to protect or stabilize a knee injury.
• Elevate the affected area.

  Try to keep the area at or above the level of your heart to help reduce swelling. Prop up the area on pillows while you apply ice and anytime you sit or lie down.

• Try not to put weight on your knee.

  Do this until you can get advice from your doctor.

  • Use a cane or crutch in the hand opposite your painful knee.
  • Use two crutches, keeping weight off the leg with the sore knee. You can get canes or crutches from most drugstores. Crutches are recommended if a cane causes you to walk with a limp.
• Avoid more swelling.

  For 48 hours, avoid things that might increase swelling. These things include hot showers, hot tubs, hot packs, and drinks that contain alcohol.

• Apply heat.
  • After 2 or 3 days, you can try applying heat to the area that hurts. Types of heat therapy include microwavable packs and disposable heating patches.
  • Apply heat for 10 to 20 minutes at a time.
  • You might also try switching between cold and heat.
• Rub the area.

  Gently massage or rub the area to relieve pain and encourage blood flow. Don't massage the affected area if it causes pain.

• Do exercises to keep flexibility.

  Try these stretches:

  • Hamstring stretch in a doorway
  • Single knee-to-chest stretch
• Avoid high-impact exercises.

  These include running, skiing, snowboarding, and playing tennis. Don't try them until your knee is no longer painful or swollen.

• Don't smoke or use other tobacco products.

  Smoking slows healing because it decreases blood supply and delays tissue repair.

If you need to use a wrap for more than 48 hours, you may have a more serious injury that needs to be checked by a doctor.

Signs of possible abuse

Most injuries are not caused by abuse. But bruises are often the first sign of possible abuse. Suspect physical abuse of a child or vulnerable adult when:

• Any injury cannot be explained or does not match the explanation.
• Repeated injuries occur.
• Explanations change for how the injury happened.

You may be able to prevent further injuries by reporting abuse. Seek help if:

• You suspect child abuse or elder abuse. Call your local child or adult protective agency, police, or a health professional, such as a doctor, nurse, or counselor.
• You or someone you know is experiencing intimate partner violence (IPV).
• You have trouble controlling your anger with a child or other person in your care.

When to call for help during self-care

Call a doctor if any of the following occur during self-care at home:

• New or worse pain or swelling.
• New signs of infection, such as redness, warmth, pus, or a fever.
• New or worse numbness, tingling, or cool and pale skin.
• Movement or strength decreases.
• Symptoms occur more often or are more severe.

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