Knee Injuries and Treatments
There are many diseases and types of injuries that can affect the knee. These are some of the most common, along with their diagnoses and treatment:
» Meniscal Injuries
» Cruciate Ligament Injuries
» Medial & Lateral Collateral Ligament Injuries
» Tendon Injuries
» Osgood-Schlatter Disease
» Iliotibial Band Syndrome
» Osteochondritis Dissecans
» Plica Syndrome
There are some 100 different forms of arthritis, rheumatic diseases, and related conditions. Virtually all of them have the potential to affect the knees in some way; however, the following are the most common.
- Osteoarthritis . Some people with knee problems have a form of arthritis called osteoarthritis. In this disease, the cartilage gradually wears away and changes occur in the adjacent bone. Osteoarthritis may be caused by joint injury or being overweight. It is associated with aging and most typically begins in people age 50 or older. A young person who develops osteoarthritis typically has had an injury to the knee or may have an inherited form of the disease.
- Rheumatoid arthritis . Rheumatoid arthritis, which generally affects people at a younger age than does osteoarthritis, is an autoimmune disease. This means it occurs as a result of the immune system attacking components of the body. In rheumatoid arthritis, the primary site of the immune system's attack is the synovium, the membrane that lines the joint. This attack causes inflammation of the joint. It can lead to destruction of the cartilage and bone and, in some cases, muscles, tendons, and ligaments as well.
- Other rheumatic diseases. These include:
- Gout . An acute and intensely painful form of arthritis that occurs when crystals of the bodily waste product uric acid are deposited in the joints
- Systemic lupus erythematosus (lupus) . An autoimmune disease characterized by destructive inflammation of the skin, internal organs, and other body systems, as well as the joints
- Ankylosing spondylitis. An inflammatory form of arthritis that primarily affects the spine, leading to stiffening and in some cases fusing into a stooped position
- Psoriatic arthritis. A condition in which inflamed joints produce symptoms of arthritis for patients who have or will develop psoriasis
- Infectious arthritis. A term describing forms of arthritis that are caused by infectious agents, such as bacteria or viruses. Prompt medical attention is essential to treat the infection and minimize damage to joints, particularly if fever is present.
The symptoms are different for the different forms of arthritis. For example, people with rheumatoid arthritis, gout, or other inflammatory conditions may find the knee swollen, red, and even hot to the touch. Any form of arthritis can cause the knee to be painful and stiff.
The doctor may confirm the diagnosis by conducting a careful history and physical examination. Blood tests may be helpful for diagnosing rheumatoid arthritis, but other tests may also be needed. Analyzing fluid from the knee joint, for example, may be helpful in diagnosing gout. X-rays may be taken to determine loss or damage to cartilage or bone.
Like the symptoms, treatment varies depending on the form of arthritis affecting the knee. For osteoarthritis, treatment is targeted at relieving symptoms and may include pain-reducing medicines such as aspirin or acetaminophen; nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen; or, in some cases, injections of corticosteroid medications directly into the knee joint. Other treatments for the pain of knee osteoarthritis include injections of hyaluronic acid substitutes and the nutritional supplements glucosamine and chondroitin sulphate.
People with diseases such as rheumatoid arthritis, ankylosing spondylitis, or psoriatic arthritis often require disease-modifying antirheumatic drugs (DMARDs) or biologic response modifiers (biologics) to control the underlying disease that is the source of their knee problems. These drugs are typically prescribed after less potent treatments, such as NSAIDs or intra-articular injections, are deemed ineffective.
DMARDs are a family of medicines that may be able to slow or stop the immune system from attacking the joints. This in turn prevents pain and swelling. DMARDs typically require regular blood tests to monitor side effects. In addition to relieving signs and symptoms, these drugs may help to retard or even stop joint damage from progressing. However, DMARDs cannot fix joint damage that has already occurred. Some of the most commonly prescribed DMARDs are methotrexate, hydroxychloroquine, sulfasalazine, and leflunomide.
Biologic response modifiers, or biologics, are a new family of genetically engineered drugs that block specific molecular pathways of the immune system that are involved in the inflammatory process. They are often prescribed in combination with DMARDs such as methotrexate. Because biologics work by suppressing the immune system, they could be problematic for patients who are prone to frequent infection. They are typically administered by injection at home or by an intravenous infusion at a clinic. Some commonly prescribed biologics include etanercept, adalimumab, infliximab, and anakinra.
People with any type of arthritis may benefit from exercises to strengthen the muscles that support the knee and from weight loss, if needed, to relieve excess stress on the joints.
If arthritis causes serious damage to a knee or there is incapacitating pain or loss of use of the knee from arthritis, joint surgery may be considered. Traditionally, this has been done with what is known as a total knee replacement. However, newer surgical procedures are continuously being developed that include resurfacing or replacing only the damaged cartilage surfaces while leaving the rest of the joint intact.
[Back to top]
Chondromalacia, also called chondromalacia patellae, refers to softening of the articular cartilage of the kneecap. This disorder occurs most often in young adults and can be caused by injury, overuse, misalignment of the patella, or muscle weakness. Instead of gliding smoothly across the lower end of the thigh bone, the kneecap rubs against it, thereby roughening the cartilage underneath the kneecap. The damage may range from a slightly abnormal surface of the cartilage to a surface that has been worn away to the bone. Chondromalacia related to injury occurs when a blow to the kneecap tears off either a small piece of cartilage or a large fragment containing a piece of bone (osteochondral fracture).
The most frequent symptom of chondromalacia is a dull pain around or under the kneecap that worsens when walking down stairs or hills. A person may also feel pain when climbing stairs or when the knee bears weight as it straightens. The disorder is common in runners and is also seen in skiers, cyclists, and soccer players.
Your description of symptoms and an x-ray usually help the doctor make a diagnosis. Although arthroscopy can confirm the diagnosis, it's not performed unless conservative treatment has failed.
Many doctors recommend that people with chondromalacia perform low-impact exercises that strengthen muscles, particularly muscles of the inner part of the quadriceps, without injuring joints. Swimming, riding a stationary bicycle, and using a cross-country ski machine are examples of good exercises for this condition. Electrical stimulation may also be used to strengthen the muscles.
Increasingly, doctors are using osteochondral grafting, in which a plug of bone and healthy cartilage is harvested from one area and transplanted to the injury site. Another relatively new technique is known as autologous chondrocyte implantation (ACI). It involves harvesting healthy cartilage cells, cultivating them in a lab, and implanting them over the lesion.
If these treatments don't improve the condition, the doctor may perform arthroscopic surgery to smooth the surface of the cartilage and "wash out" the cartilage fragments that cause the joint to catch during bending and straightening. In more severe cases, surgery may be necessary to correct the angle of the kneecap and relieve friction between it and the cartilage, or to reposition parts that are out of alignment.
[Back to top]
Meniscal Injuries (Injuries to the Mensici)
The menisci can be easily injured by the force of rotating the knee while bearing weight. A partial or total tear of the menisci may occur when a person quickly twists or rotates the upper leg while the foot stays still (for example, when dribbling a basketball around an opponent or turning to hit a tennis ball). If the tear is tiny, the meniscus stays connected to the front and back of the knee; if the tear is large, the meniscus may be left hanging by a thread of cartilage. The seriousness of a tear depends on its location and extent.
Generally, when people injure a meniscus, they feel some pain, particularly when the knee is straightened. If the pain is mild, the person may continue moving. Severe pain may occur if a fragment of the meniscus catches between the femur and the tibia. Swelling may occur soon after injury if there is damage to blood vessels. Swelling may also occur several hours later if there is inflammation of the joint lining (synovium). Sometimes, an injury that occurred in the past but was not treated becomes painful months or years later, particularly if the knee is injured a second time. After any injury, the knee may click, lock, feel weak, or give way. Although symptoms of meniscal injury may disappear on their own, they frequently persist or return and require treatment.
In addition to listening to your description of the onset of pain and swelling, the doctor may perform a physical examination and take x-ray of the knee. An MRI may be recommended to confirm the diagnosis. Occasionally, the doctor may use arthroscopy to help diagnose a meniscal tear.
If the tear is minor and the pain and other symptoms go away, the doctor may recommend a muscle-strengthening program. The following exercises are designed to build up the quadriceps and hamstring muscles and increase flexibility and strength after injury to the meniscus:
- Warming up the joint by riding a stationary bicycle, then straightening and raising the leg (but not straightening it too much).
- Extending the leg while sitting (a weight may be worn on the ankle for this exercise).
- Raising the leg while lying on the stomach.
- Exercising in a pool (walking as fast as possible in chest-deep water, performing small flutter kicks while holding onto the side of the pool, and raising each leg to 90 degrees in chest-deep water while pressing the back against the side of the pool).
Before beginning any type of exercise program, consult your doctor or physical therapist to learn which exercises are appropriate for you and how to do them correctly, because doing the wrong exercise or exercising improperly can cause problems. A health care professional can also advise you on how to warm up safely and when to avoid exercising a joint affected by arthritis.
If your lifestyle is limited by the symptoms or the problem, the doctor may perform arthroscopic or open surgery to see the extent of injury and to remove or repair the tear. Most young athletes are able to return to active sports after meniscus repair.
Recovery after surgical repair takes several weeks. The best results of treatment for meniscal injury are achieved in people who do not show articular cartilage changes and who have an intact anterior cruciate ligament.
[Back to top]
Cruciate Ligament Injuries
Cruciate ligament injuries are sometimes referred to as sprains. They don't necessarily cause pain, but they are disabling. The anterior cruciate ligament is most often stretched or torn (or both) by a sudden twisting motion (for example, when the feet are planted one way and the knees are turned another). The posterior cruciate ligament is most often injured by a direct impact, such as in an automobile accident or football tackle.
You may hear a popping sound, and the leg may buckle when you try to stand on it.
The doctor may perform several tests to see whether the parts of the knee stay in proper position when pressure is applied in different directions. A thorough examination is essential. An MRI is accurate in detecting a complete tear, but arthroscopy may be the only reliable means of detecting a partial one.
For an incomplete tear, the doctor may recommend an exercise program to strengthen surrounding muscles. He or she may also prescribe a brace to protect the knee during activity. For a completely torn anterior cruciate ligament in an active athlete and motivated person, the doctor is likely to recommend surgery. The surgeon may reconstruct the torn ligament by using a piece (graft) of healthy tissue from you (autograft) or from a cadaver (allograft). Although synthetic ligaments have been tried in experiments, the results have not been as good as with human tissue. One of the most important elements in a successful recovery after cruciate ligament surgery is a 4- to 6-month exercise and rehabilitation program that may involve using special exercise equipment at a rehabilitation or sports center. Successful surgery and rehabilitation will allow the person to return to a normal lifestyle.
[Back to top]
Medial and Lateral Collateral Ligament Injuries
The medial collateral ligament is more easily injured than the lateral collateral ligament. The cause of collateral ligament injuries is most often a blow to the outer side of the knee that stretches and tears the ligament on the inner side of the knee. Such blows frequently occur in contact sports such as football or hockey.
When injury to the medial collateral ligament occurs, you may feel a pop and the knee may buckle sideways. Pain and swelling are common.
A thorough examination is needed to determine the type and extent of the injury. In diagnosing a collateral ligament injury, the doctor exerts pressure on the side of the knee to determine the degree of pain and the looseness of the joint. An MRI is helpful in diagnosing injuries to these ligaments.
Most sprains of the collateral ligaments will heal if you follow a prescribed exercise program. In addition to exercise, the doctor may recommend ice packs to reduce pain and swelling, and a small sleeve-type brace to protect and stabilize the knee. A sprain may take 2 to 4 weeks to heal. A severely sprained or torn collateral ligament may be accompanied by a torn anterior cruciate ligament, which usually requires surgical repair.
[Back to top]
Knee tendon injuries range from tendinitis (inflammation of a tendon) to a ruptured (torn) tendon. If a person overuses a tendon during certain activities such as dancing, cycling, or running, the tendon stretches and becomes inflamed. Tendinitis of the patellar tendon is sometimes called " jumper's knee" because in sports that require jumping, such as basketball, the muscle contraction and force of hitting the ground after a jump strain the tendon. After repeated stress, the tendon may become inflamed or tear.
People with tendinitis often have tenderness at the point where the patellar tendon meets the bone. In addition, they may feel pain during running, hurried walking, or jumping. A complete rupture of the quadriceps or patellar tendon is not only painful, but also makes it difficult for a person to bend, extend, or lift the leg against gravity.
If there is not much swelling, the doctor will be able to feel a defect in the tendon near the tear during a physical examination. An x-ray will show that the patella is lower than normal in a quadriceps tendon tear and higher than normal in a patellar tendon tear. The doctor may use an MRI to confirm a partial or total tear.
Initially, the treatment for tendinitis involves rest, elevating the knee, applying ice, and taking NSAID medications such as aspirin or ibuprofen to relieve pain and decrease inflammation and swelling. A series of rehabilitation exercises is also useful. If the quadriceps or patellar tendon is completely ruptured, a surgeon will reattach the ends. After surgery, a cast is worn for 3 to 6 weeks and crutches are used. For a partial tear, the doctor might apply a cast without performing surgery.
Rehabilitating a partial or complete tear of a tendon requires an exercise program that is similar to but less vigorous than that prescribed for ligament injuries. The goals of exercise are to restore the ability to bend and straighten the knee and to strengthen the leg to prevent repeat injury. A rehabilitation program may last 6 months, although people can resume many activities before then.
[Back to top]
Osgood-Schlatter disease is a condition caused by repetitive stress or tension on part of the growth area of the upper tibia (the apophysis). It is characterized by inflammation of the patellar tendon and surrounding soft tissues at the point where the tendon attaches to the tibia. The disease may also be associated with an injury in which the tendon is stretched so much that it tears away from the tibia and takes a fragment of bone with it. The disease most commonly affects active young people, particularly boys between the ages of 10 and 15, who play games or sports that include frequent running and jumping.
People with this disease experience pain just below the knee joint that usually worsens with activity and is relieved by rest. A bony bump that is particularly painful when pressed may appear on the upper edge of the tibia (below the kneecap). Usually, the motion of the knee is not affected. Pain may last a few months and may recur until the child's growth is completed.
Osgood-Schlatter disease is most often diagnosed by the symptoms. An x-ray may be normal, or show an injury, or, more typically, show that the growth area is in fragments.
Osgood-Schlatter disease is temporary and the pain usually goes away without treatment. Applying ice to the knee when pain begins helps relieve inflammation and is sometimes used along with stretching and strengthening exercises. The doctor may advise you to limit participation in vigorous sports. Children who wish to continue moderate or less stressful sports activities may need to wear knee pads for protection and apply ice to the knee after activity. If there is a great deal of pain, sports activities may be limited until the discomfort becomes tolerable.
[Back to top]
Iliotibial Band Syndrome
Iliotibial band syndrome is an inflammatory condition caused when a band of tissue rubs over the outer bone (lateral condyle) of the knee. Although iliotibial band syndrome may be caused by direct injury to the knee, it is most often caused by the stress of long-term overuse, such as sometimes occurs in sports training and, particularly, in running.
A person with this syndrome feels an ache or burning sensation at the side of the knee during activity. Pain may be localized at the side of the knee or radiate up the side of the thigh. A person may also feel a snap when the knee is bent and then straightened. Swelling is usually absent, and knee motion is normal.
The diagnosis of this disorder is typically based on the symptoms, such as pain at the outer bone, and exclusion of other conditions with similar symptoms.
Usually, iliotibial band syndrome disappears if the person reduces activity and performs stretching exercises followed by muscle-strengthening exercises. In rare cases when the syndrome doesn't disappear, surgery may be necessary to split the tendon so it isn't stretched too tightly over the bone.
[Back to top]
Osteochondritis dissecans results from a loss of the blood supply to an area of bone underneath a joint surface. It usually involves the knee. The affected bone and its covering of cartilage gradually loosen and cause pain. This problem usually arises spontaneously in an active adolescent or young adult. It may be caused by a slight blockage of a small artery or to an unrecognized injury or tiny fracture that damages the overlying cartilage. A person with this condition may eventually develop osteoarthritis.
Lack of a blood supply can cause bone to break down (osteonecrosis). The involvement of several joints or the appearance of osteochondritis dissecans in several family members may indicate that the disorder is inherited.
If normal healing doesn't occur, cartilage separates from the diseased bone and a fragment breaks loose into the knee joint, causing weakness, sharp pain, and locking of the joint.
An x-ray, MRI, or arthroscopy can determine the condition of the cartilage and can be used to diagnose osteochondritis dissecans.
If cartilage fragments have not broken loose, a surgeon may fix them in place with pins or screws that are sunk into the cartilage to stimulate a new blood supply. If fragments are loose, the surgeon may scrape down the cavity to reach fresh bone, add a bone graft, and fix the fragments in position. Fragments that cannot be mended are removed, and the cavity is drilled or scraped to stimulate new cartilage growth. Research is being done to assess the use of cartilage cell and other tissue transplants to treat this disorder.
[Back to top]
Plica syndrome occurs when plicae (bands of synovial tissue) are irritated by overuse or injury. Synovial plicae are the remains of tissue pouches found in the early stages of fetal development. As the fetus develops, these pouches normally combine to form one large synovial cavity. If this process is incomplete, plicae remain as four folds or bands of synovial tissue within the knee. Injury, chronic overuse, or inflammatory conditions are associated with this syndrome.
Symptoms of plica syndrome include pain and swelling, a clicking sensation, and locking and weakness of the knee.
Because the symptoms are similar to those of some other knee problems, plica syndrome is often misdiagnosed. Diagnosis usually depends on excluding other conditions that cause similar symptoms.
The goal of treatment for plica syndrome is to reduce inflammation of the synovium and thickening of the plicae. The doctor usually prescribes medicine such as ibuprofen to reduce inflammation. People are also advised to reduce activity, apply ice and an elastic bandage to the knee, and do strengthening exercises. A cortisone injection into the plica folds helps about half of those treated. If treatment fails to relieve symptoms within 3 months, the doctor may recommend arthroscopic or open surgery to remove the plicae.
[Back to top]
Above content provided by National Institute of Arthritis and Musculoskeletal and Skin Diseases in partnership with Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
Posted March 2011