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Knee Problems and Injuries

Topic Overview

Most people have had a minor knee problem at one time or another. Most of the time our body movements do not cause problems, but it's not surprising that 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 knee is the largest joint in the body. 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, which absorbs shock and provides a smooth, gliding surface for joint movement. See a picture of the structures of the knee.

Although a knee problem is often caused by an injury to one or more of these structures, it may have another cause. Some people are more likely to develop knee problems than others. Many jobs, sports and recreation 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 from abnormal twisting, bending the knee, or falling on the knee. Pain, bruising, or swelling may be severe and develop 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; 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).
Ligament tears, such as the anterior cruciate ligament (ACL). The medial collateral ligament (MCL) is the most commonly 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 commonly caused by abnormal force, such as a falling on the knee, a severe twisting motion, severe force that bends the knee, or when the knee forcefully hits an object.
Kneecap dislocation. This type of dislocation occurs more frequently in 13- to 18-year-old girls.
Pieces of bone or tissue (loose bodies) from a fracture or dislocation that may get caught in the joint and interfere with movement.
Knee joint dislocation. This is a rare injury that requires great force. It is a serious injury and requires immediate medical care.

Overuse injuries

Overuse injuries occur with repetitive activities or repeated or prolonged pressure on the knee. Activities such as stair climbing, bicycle riding, jogging, or jumping stress joints and other tissues and can lead to irritation and inflammation. 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.

Osteoarthritis (degenerative joint disease) may cause knee pain that is worse in the morning and improves during the day. It often develops at the site of a previous injury. Other types of arthritis, such as rheumatoid arthritis, gout, and lupus, also can cause knee pain, swelling, and stiffness.
Osgood-Schlatter disease causes pain, swelling, and tenderness in the front of the knee below the kneecap. It is especially common in boys ages 11 to 15.
A popliteal (or Baker's) cyst causes swelling in the back of the knee.
Infection in the skin (cellulitis), joint (infectious arthritis), bone (osteomyelitis), or bursa (septic bursitis) can cause pain and decreased knee movement.
A problem elsewhere in the body, such as a pinched nerve or a problem in the hip, can sometimes cause knee pain.
Osteochondritis dissecans 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 measures, rest, bracing, physical therapy, medicine, and, in some cases, surgery. Treatment depends on the location, type, and severity of the injury as well as your age, health condition, and activity level (such as work, sports, or hobbies).

Check your symptoms to decide if and when you should see a doctor.

Check Your Symptoms

Do you have a knee injury or other knee problem?

Yes

Knee problem or injury

How old are you?

Less than 5 years

5 years or older

Are you male or female?

Male

Female

Have you had knee surgery in the past month?

If a cast, splint, or brace is causing the problem, follow the instructions you got about how to loosen it.

Yes

Knee surgery in the past month

Have you had a major trauma in the past 2 to 3 hours?

Yes

Major trauma in past 2 to 3 hours

Do you have severe bleeding that has not slowed down with direct pressure?

Yes

Severe bleeding

Do you have symptoms of shock?

The symptoms in an adult or older child are different than the symptoms in a young child.

Yes

Symptoms of shock

Is the leg blue, very pale, or cold and different from the other leg?

If the leg is in a cast, splint, or brace, follow the instructions you got about how to loosen it.

Yes

Leg is blue, very pale, or cold and different from other leg

Is there any knee pain?

Yes

Knee pain

How bad is the pain on a scale of 0 to 10, if 0 is no pain and 10 is the worst pain you can imagine?

Signs of pain in a baby or toddler are different than signs of pain in an older child.

5 to 10: Moderate to severe pain

Moderate to severe pain

1 to 4: Mild pain

Mild pain

Has the pain:

Gotten worse?

Pain is increasing

Stayed about the same (not better or worse)?

Pain is unchanged

Gotten better?

Pain is improving

Do you have any pain in your knee?

Yes

Knee pain

How bad is the pain on a scale of 0 to 10, if 0 is no pain and 10 is the worst pain you can imagine?

8 to 10: Severe pain

Severe pain

5 to 7: Moderate pain

Moderate pain

1 to 4: Mild pain

Mild pain

How long has the pain lasted?

Less than 2 full days (48 hours)

Pain less than 2 days

2 days to 2 weeks

Pain 2 days to 2 weeks

More than 2 weeks

Pain more than 2 weeks

Has the pain:

Gotten worse?

Pain is getting worse

Stayed about the same (not better or worse)?

Pain is unchanged

Gotten better?

Pain is getting better

Have you had a knee injury in the past month?

Yes

Knee injury in the past month

Are you having trouble moving your knee normally?

Yes

Difficulty moving knee

Can you move the knee at all?

Yes

Able to move the knee

Unable to move the knee

Have you had trouble moving your knee for more than 2 days?

Yes

Difficulty moving knee for more than 2 days

Did the knee or kneecap get twisted out of shape or pop out of its normal position?

This is called dislocation.

Yes

Knee was out of normal position

Is the knee still out of place?

Yes

Knee is still out of position

Is this the first time the knee has ever popped out of place?

Yes

First time that knee has been dislocated

Does the knee feel loose or unstable when you try to walk?

Yes

Knee feels loose or unstable

Is there any swelling or bruising?

Yes

Swelling or bruising

Did you have swelling or bruising within 30 minutes of the injury?

Yes

Swelling or bruising within 30 minutes of injury

Has swelling lasted for more than 2 days?

Yes

Swelling for more than 2 days

Do you have trouble moving your knee?

Yes

Difficulty moving knee

Is it very hard to move or somewhat hard to move?

"Very hard" means you can't move it at all in any direction without causing severe pain. "Somewhat hard" means you can move it at least a little, though you may have some pain when you do it.

Very hard

Very hard to move

Somewhat hard

Somewhat hard to move

How long have you had trouble moving your knee?

Less than 2 days

Difficulty moving knee for less than 2 days

2 days to 2 weeks

Difficulty moving knee for 2 days to 2 weeks

More than 2 weeks

Difficulty moving knee for more than 2 weeks

Has the loss of movement been:

Getting worse?

Difficulty moving is getting worse

Staying about the same (not better or worse)?

Difficulty moving is unchanged

Getting better?

Difficulty moving is improving

Is there any swelling?

Yes

Swelling

Has the knee been swollen for more than 2 full days (48 hours)?

Yes

Knee swollen for more than 48 hours

Do you think that the knee problem may have been caused by abuse?

Yes

Knee problem may have been caused by abuse

Do you think the problem may be causing a fever?

Some bone and joint problems can cause a fever.

Yes

Possible fever

Are there any symptoms of infection?

Yes

Symptoms of infection

Are there red streaks leading away from the area or pus draining from it?

Yes

Red streaks or pus

Do you have diabetes, a weakened immune system, peripheral arterial disease, or any surgical hardware in the area?

"Hardware" includes things like artificial joints, plates or screws, catheters, and medicine pumps.

Yes

Diabetes, immune problems, peripheral arterial disease, or surgical hardware in affected area

How long have you had knee symptoms?

Less than 1 week

Symptoms for less than 1 week

1 to 2 weeks

Symptoms for 1 to 2 weeks

More than 2 weeks

Symptoms for more than 2 weeks

Seek Care Now

Based on your answers, you may need care right away. The problem is likely to get worse without medical care.

Call your doctor now to discuss the symptoms and arrange for care.
If you cannot reach your doctor or you don't have one, seek care in the next hour.
You do not need to call an ambulance unless:
- You cannot travel safely either by driving yourself or by having someone else drive you.
- You are in an area where heavy traffic or other problems may slow you down.

Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.

Symptoms of shock in a child may include:

Passing out.
Being very sleepy or hard to wake up.
Not responding when being touched or talked to.
Breathing much faster than usual.
Acting confused. The child may not know where he or she is.

Pain in children under 3 years

It can be hard to tell how much pain a baby or toddler is in.

Severe pain (8 to 10): The pain is so bad that the baby cannot sleep, cannot get comfortable, and cries constantly no matter what you do. The baby may kick, make fists, or grimace.
Moderate pain (5 to 7): The baby is very fussy, clings to you a lot, and may have trouble sleeping but responds when you try to comfort him or her.
Mild pain (1 to 4): The baby is a little fussy and clings to you a little but responds when you try to comfort him or her.

Major trauma is any event that can cause very serious injury, such as:

A fall from more than 10 ft (3.1 m) [more than 5 ft (1.5 m) for children under 2 years and adults over 65].
A car crash in which any vehicle involved was going more than 20 miles (32 km) per hour.
Any event that causes severe bleeding that you cannot control.
Any event forceful enough to badly break a bone.

Pain in adults and older children

Severe pain (8 to 10): The pain is so bad that you can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain.
Moderate pain (5 to 7): The pain is bad enough to disrupt your normal activities and your sleep, but you can tolerate it for hours or days. Moderate can also mean pain that comes and goes even if it's severe when it's there.
Mild pain (1 to 4): You notice the pain, but it is not bad enough to disrupt your sleep or activities.

Try Home Treatment

You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.

Try home treatment to relieve the symptoms.
Call your doctor if symptoms get worse or you have any concerns (for example, if symptoms are not getting better as you would expect). You may need care sooner.

HomeTreatment

RelatedInformation

Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in adults are:

Diseases such as diabetes, cancer, heart disease, and HIV/AIDS.
Long-term alcohol and drug problems.
Steroid medicines, which may be used to treat a variety of conditions.
Chemotherapy and radiation therapy for cancer.
Other medicines used to treat autoimmune disease.
Medicines taken after organ transplant.
Not having a spleen.

With severe bleeding, any of these may be true:

Blood is pumping from the wound.
The bleeding does not stop or slow down with pressure.
Blood is quickly soaking through bandage after bandage.

With moderate bleeding, any of these may be true:

The bleeding slows or stops with pressure but starts again if you remove the pressure.
The blood may soak through a few bandages, but it is not fast or out of control.

With mild bleeding, any of these may be true:

The bleeding stops on its own or with pressure.
The bleeding stops or slows to an ooze or trickle after 15 minutes of pressure. It may ooze or trickle for up to 45 minutes.

Seek Care Today

Based on your answers, you may need care soon. The problem probably will not get better without medical care.

Call your doctor today to discuss the symptoms and arrange for care.
If you cannot reach your doctor or you don't have one, seek care today.
If it is evening, watch the symptoms and seek care in the morning.
If the symptoms get worse, seek care sooner.

HomeTreatment

RelatedInformation

Call 911 Now

Based on your answers, you need emergency care.

Call911or other emergency services now.

Put direct, steady pressure on the wound until help arrives. Keep the area raised if you can.

Postoperative Problems

Many things can affect how your body responds to a symptom and what kind of care you may need. These include:

Your age. Babies and older adults tend to get sicker quicker.
Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
Medicines you take. Certain medicines, herbal remedies, and supplements can cause symptoms or make them worse.
Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.

When an area turns blue, very pale, or cold, it can mean that there has been a sudden change in the blood supply to the area. This can be serious.

There are other reasons for color and temperature changes. Bruises often look blue. A limb may turn blue or pale if you leave it in one position for too long, but its normal color returns after you move it. What you are looking for is a change in how the area looks (it turns blue or pale) and feels (it becomes cold to the touch), and this change does not go away.

Symptoms of infection may include:

Increased pain, swelling, warmth, or redness in or around the area.
Red streaks leading from the area.
Pus draining from the area.
A fever.

Call 911 Now

Based on your answers, you need emergency care.

Call911or other emergency services now.

Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.

Symptoms of shock (most of which will be present) include:

Passing out.
Feeling very dizzy or lightheaded, like you may pass out.
Feeling very weak or having trouble standing.
Not feeling alert or able to think clearly. You may be confused, restless, fearful, or unable to respond to questions.

Make an Appointment

Based on your answers, the problem may not improve without medical care.

Make an appointment to see your doctor in the next 1 to 2 weeks.
If appropriate, try home treatment while you are waiting for the appointment.
If symptoms get worse or you have any concerns, call your doctor. You may need care sooner.

HomeTreatment

RelatedInformation

Pain in children 3 years and older

Severe pain (8 to 10): The pain is so bad that the child can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain. No one can tolerate severe pain for more than a few hours.
Moderate pain (5 to 7): The pain is bad enough to disrupt the child's normal activities and sleep, but the child can tolerate it for hours or days.
Mild pain (1 to 4): The child notices and may complain of the pain, but it is not bad enough to disrupt his or her sleep or activities.

Home Treatment

Home treatment may help relieve pain, swelling, and stiffness.

Rest and protect an injured or sore area. Stop, change, or take a break from any activity that may be causing your pain or soreness. When resting, place a small pillow under your knee.
Ice will reduce pain and swelling. Apply ice or cold packs immediately to prevent or minimize swelling. Apply the ice or cold pack for 10 to 20 minutes, 3 or more times a day.
- For the first 48 hours after an injury, avoid things that might increase swelling, such as hot showers, hot tubs, hot packs, or alcoholic beverages.
- After 48 to 72 hours, if swelling is gone, apply heat and begin gentle exercise with the aid of moist heat to help restore and maintain flexibility. Some experts recommend alternating between heat and cold treatments.
Compression, or wrapping the injured or sore area with an elastic bandage (such as an Ace wrap), will help decrease swelling.
- Don't wrap it too tightly, since this 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, or swelling in the area below the bandage.
- Don't expect the bandage to protect or stabilize a knee injury.
- Talk to your doctor if you think you need to use a wrap for longer than 48 to 72 hours. A more serious problem may be present.
Elevate the injured or sore area on pillows while applying ice and anytime you are sitting or lying down. Try to keep the area at or above the level of your heart to help minimize swelling.
Reduce stress on your sore knee (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 pharmacies. Crutches are recommended if a cane causes you to walk with a limp.
Gently massage or rub the area to relieve pain and encourage blood flow. Do not massage the injured area if it causes pain.
Try the following exercises to maintain flexibility:
- Hamstring stretch
- Knee-to-chest exercise
Avoid high-impact exercise, such as running, skiing, snowboarding, or playing tennis, until your knee is no longer painful or swollen.

Do not smoke. Smoking slows healing because it decreases blood supply and delays tissue repair. For more information, see the topic Quitting Smoking.

**Medicine you can buy without a prescription**
Try a nonprescription medicine to help treat your fever or pain:
Acetaminophen, such as Tylenol Nonsteroidal anti-inflammatory drugs (NSAIDs): Ibuprofen, such as Advil or Motrin Naproxen, such as Aleve or Naprosyn Aspirin (also a nonsteroidal anti-inflammatory drug), such as Bayer or Bufferin Talk to your child's doctor before switching back and forth between doses of acetaminophen and ibuprofen. When you switch between two medicines, there is a chance your child will get too much medicine.

**Safety tips**
Be sure to follow these safety tips when you use a nonprescription medicine:
Carefully read and follow all directions on the medicine bottle and box. Do not take more than the recommended dose. Do not take a medicine if you have had an allergic reaction to it in the past. If you have been told to avoid a medicine, call your doctor before you take it. If you are or could be pregnant, do not take any medicine other than acetaminophen unless your doctor has told you to. Do not give aspirin to anyone younger than age 20 unless your doctor tells you to.

Symptoms to watch for during home treatment

Call your doctor if any of the following occur during home treatment:

Signs of infection develop.
Your knee becomes hard to move or swelling lasts for more than 2 days.
Your knee, lower leg, or foot becomes pale or cool or looks blue.
Symptoms do not improve with home treatment.
Symptoms become more severe or frequent.

Prevention

The following tips may prevent knee problems.

General prevention tips

Wear your seat belt in a motor vehicle.
Don't carry objects that are too heavy. Use a step stool. Do not stand on chairs or other unsteady objects.
Wear knee guards during sports or recreational activities, such as roller-skating or soccer.
Stretch before and after physical exercise, sports, or recreational activities to warm up your muscles.
Use the correct techniques or positions during activities so that you do not strain your muscles.
Use equipment appropriate to your size, strength, and ability. Avoid repeated movements that can cause injury. In daily routines or hobbies, look at activities in which you make repeated knee movements.
Consider taking lessons to learn the proper technique for sports. Have a trainer or person who is familiar with sports equipment check your equipment to see if it is well suited for your level of ability, body size, and body strength.
If you feel that certain activities at your workplace are causing pain or soreness from overuse, call your human resources department for information on other ways of doing your job or to talk about using different equipment.

Tips specific to the knee

Keep your knees and the muscles that support them strong and flexible. Warm up before activities. Try the following stretches:
Avoid activities that stress your knees, such as deep knee bends or downhill running.
Wear shoes with good arch supports.
Do not wear high-heeled shoes.
When playing contact sports, wear the right shoes that are made for the surface you are playing or running on, such as a track or tennis court.
Replace running shoes every 300 to 500 miles (480 to 800 kilometers). Experts recommend getting new athletic shoes every 3 months or after 500 miles of wear.

Tips specific to female athletes

Sports trainers recommend training programs that help women learn to run, jump, and pivot with knees bent to avoid knee injuries. In sports such as soccer, basketball, and volleyball, women who bend their knees and play low to the ground have fewer knee injuries than women who run and pivot with stiff legs.

Knee brace use

Some people use knee braces to prevent knee injuries or after a knee injury. There are many types of knee braces, from soft fabric sleeves to rigid, metal hinged braces, that support and protect the knee. If your doctor has recommended the use of a knee brace, follow his or her instructions. If you are using a knee brace to help prevent problems, follow the manufacturer's instructions for use.

Keep bones strong

Eat healthy foods such as milk, cheese, yogurt, and dark green, leafy vegetables like broccoli. For more information, see the topic Healthy Eating.
Exercise and stay active. Talk to your doctor about exercises and activities that are right for you. Begin slowly, especially if you have been inactive. For more information, see the topic Fitness.
Don't drink more than 2 alcoholic drinks a day if you are a man, or 1 alcoholic drink a day if you are a woman. Drinking alcohol increases your chances of having weak bones (osteoporosis). It also increases your chances of falling.
Do not smoke or use other tobacco products. Smoking increases your chances of having osteoporosis. It also causes problems with the blood supply in your legs and slows healing. For more information, see the topic Quitting Smoking.

Possible abuse

Knee injuries such as bruises, burns, fractures, cuts, or punctures may be caused by abuse. Suspect possible abuse when an injury cannot be explained or does not match the explanation, repeated injuries occur, or the explanations for the cause of the injury change. You may be able to prevent further abuse by reporting it and seeking help.

Preparing For Your Appointment

To prepare for your appointment, see the topic Making the Most of Your Appointment.

You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:

What are your main symptoms?
How long have you had your symptoms?
What were you doing when your symptoms started?
Have you had this problem in the past?
- What was the diagnosis?
- How was it treated?
How and when did an injury occur? How was it treated? Were illegal drugs or alcohol involved in your injury?
Have you had any injuries in the past to the same area? Do you have any continuing problems because of the previous injury?
Have you ever had knee surgery?
What activities, related to sports, work, or your lifestyle, make your symptoms better or worse?
Do you think that activities related to your job or hobbies caused your symptoms?
What home treatment measures have you tried? Did they help?
What nonprescription medicines have you taken? Did they help?
Do you have any health risks?

Related Information

Credits

By	Healthwise Staff
	William H. Blahd, Jr., MD, FACEP - Emergency Medicine
	David Messenger, MD
Last Revised	May 23, 2013

Top of Page
Next Section:
Check Your Symptoms

Last Revised: May 23, 2013

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & David Messenger, MD

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