The knee is the joint where the bones of the upper leg meet the bones of the lower leg, allowing hinge-like movement while providing stability and strength to support the weight of the body. Flexibility, strength, and stability are needed for standing and for motions like walking, running, crouching, jumping, and turning.
Several kinds of supporting and moving parts, including bones, cartilage, muscles, ligaments, and tendons, help the knees do their job. Each of these structures is subject to disease and injury. When a knee problem affects ability to do things, it can have a big impact on routine life. Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking.
Injured part of the body- The largest and most complicated joint, the knee is used for everything from standing up, sitting, to walking, running, etc. It’s a weight-bearing joint that straightens, bends, twists and rotates. All this motion increases your risk of acute or overuse knee injuries.
Acute knee injuries- (including torn ligaments and torn cartilage) are often caused by twisting the knee or falling. Sports that involve running and jumping and sudden stopping and turning, such as soccer, basketball, volleyball, tennis, and baseball, as well as contact sports such as football, wrestling, and hockey increase the risk of an acute knee injury.
But more common than sudden knee injuries are injuries caused by overuse or overload.
Common problems that affects the knee:
Arthritis is among the most common causes of knee pain, and there are many treatments available. arthritis can be osteoarthritis,rheumatoid arthritis,septic arthritis.Arthritis1
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: Most people with knee problems have a form of arthritis called osteoarthritis.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.
Primary osteoarthritis is mostly related to aging. With aging, the water content of the cartilage increases, and the protein makeup of cartilage degenerates. Eventually, cartilage begins to degenerate by flaking or forming tiny crevasses. In advanced cases, there is a total loss of cartilage cushion between the bones of the joints. Repetitive use of the worn joints over the years can irritate and inflame the cartilage, causing joint pain and swelling. Loss of the cartilage cushion causes friction between the bones, leading to pain and limitation of joint mobility. Inflammation of the cartilage can also stimulate new bone outgrowths (spurs, also referred to as osteophytes) to form around the joints. Osteoarthritis occasionally can develop in multiple members of the same family, implying a hereditary (genetic) basis for this condition.
Secondary osteoarthritis is caused by another disease or condition. Conditions that can lead to secondary osteoarthritis include obesity, repeated trauma or surgery to the joint structures, abnormal joints at birth (congenital abnormalities), gout, diabetes, and other hormone disorders.
Obesity causes osteoarthritis by increasing the mechanical stress on the cartilage. In fact, next to aging, obesity is the most powerful risk factor for osteoarthritis of the knees. The early development of osteoarthritis of the knees among weight lifters is believed to be in part due to their high body weight. Repeated trauma to joint tissues (ligaments, bones, and cartilage) is believed to lead to early osteoarthritis of the knees in soccer players. Interestingly, recent studies have not found an increased risk of osteoarthritis in long-distance runners.
Crystal deposits in the cartilage can cause cartilage degeneration and osteoarthritis. Uric acid crystals cause arthritis in gout, while calcium pyrophosphate crystals cause arthritis in pseudogout.
Some people are born with abnormally formed joints (congenital abnormalities) that are vulnerable to mechanical wear, causing early degeneration and loss of joint cartilage. Osteoarthritis of the hip joints is commonly related to structural abnormalities of these joints that had been present since birth.
Hormone disturbances, such as diabetes and growth hormone disorders, are also associated with early cartilage wear and secondary osteoarthritis.
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.
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
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.
Ligament injuries commonly occur during athletic activities and can cause discomfort and instability.
Overuse knee injuries (including muscle strain, tendonitis and bursitis) may develop gradually over days or weeks. Pain is often mild and intermittent in the beginning and worsens over time. When muscles and tendons are stressed even slightly beyond their capabilities, microscopic tears occur. (Inflammation, which is part of the healing process, is what causes the pain). These tears must be given a chance to heal before subjected to the same activity to avoid overuse injury. Treat overuse injuries early to prevent chronic problems.
Knee pain is commonly caused by doing too much too soon when you haven’t exercised for a long period of time – especially high-impact aerobics; walking, running or jumping on hard surfaces or uneven ground; excessive running up and down stairs (When you walk upstairs you are putting pressure on your knees that is equivalent to four times your body weight, when running up the stairs it can be eight times your body weight).
Knee osteoarthritis is a common cause of knee pain. The risk increases with age. Osteoarthritis is a form of arthritis involving degeneration of the cartilage. Exercise is vital to maintain strength and flexibility of muscles supporting the knee, which reduces the stress on the knee joint.
People with knee osteoarthritis may also need to take pain medications and/or other complementary pain treatments.
Runners knee (also called patellofemoral pain or anterior knee pain) is a common cause of knee pain in young people (not just in runners). The pain is usually diffuse pain behind the kneecap. Symptoms often worsen after climbing stairs, jumping, running, or after a period of sitting. Caused by poor tracking of the kneecap, appropriate exercises prescribed by a doctor or physical therapist is the main treatment in correcting runners knee. Stay away from high-impact activity if you have this condition.
Prevent knee pain by keeping the muscles that support your knees strong and flexible. Start out slowly. Walk before you run – before you engage in a strenuous high impact activity such as jogging or running, try walking for a week. If walking causes knee pain, you shouldn’t be running. Warm up and stretch before working out. Give your body a chance to recover from exercise. If you do high impact activities take every other day off. Avoid running up and down stairs and full squats.
Doing knee exercises to strengthen and stretch the muscles that support the knee are vital for knee pain and injury prevention. Proper footwear is also important, especially if walking or running on hard surfaces. Keep your weight under control. Reducing one’s weight reduces stress upon the knee.
Most knee pain is treated conservatively, but there are situations in which surgery is required. Athletes are at an elevated risk for sudden injuries that may require surgery, such as torn ligaments in the center of the knee or certain types of fractures. People with advanced knee osteoarthritis may need knee replacement surgery if they are severely limited in day-to- day activities because of their condition. This is optional surgery and is a last resort.
Most knee conditions respond to a combination of non-invasive treatments such as applying heat or cold, temporarily restraining from activities that aggravate pain, and medications that target pain and inflammation. Exercises to strengthen the muscles that support the knee help reduce stress on the knee joint and prevent re-injury.
Commonly patient present with pain in joint.Pain can be present at different sites at knee and can vary according to time and movement
The location of the pain can be an important part of tracking down the symptoms.
Front of the knee: Pain over the front of the knee is most commonly related to the knee cap. Kneecap pain can be caused by several different problems.
Inside of the knee: Pain on the inside, or medial aspect, of the knee is commonly caused by medial meniscus tears, medial collateral ligament injuries, and arthritis of the joint.
Outside of the knee: Pain on the outside of the knee, or lateral aspect of the knee joint, is commonly caused by lateral meniscus tears, lateral collateral ligament injuries, IT band tendonitis, and arthritis of the joint.
Pain in the back of the knee: Pain in the back of the knee can be due to the formation of a cyst, called a Baker’s Cyst, in the back of the knee joint. Also common is for kneecap pain to be felt in the back of the knee.
Timing of Pain
Some common situations cause pain typical of certain conditions.
While going down stairs: Pain while walking down steps is very commonly associated with kneecap problems, such as chondromalacia.
Morning pain: Pain after first waking in the morning that resolves with gentle activity is typical of early arthritis. Often patients loosen the knee over the course of the day.
Others problems that can be associated with knee pain are.
Popping and snapping within the knee is quite common, and often not a symptom of any particular problem. When the pops or snaps are painless, there is usually no problem–the bigger concern is when these sounds are associated with pain. A pop is often heard or felt when a ligament, such as the ACL, is torn.
A sense of grinding or crunching is most often associated with bone grinding against bone once the cartilage is worn away. This is commonly found in arthritis. Patients who are young (under 50 years old) seldom have arthritis that will cause these severe symptoms, unless there has been a severe injury to the knee in the past.
Locking is a symptom that occurs when a patient cannot bend or straighten their knee. The locking can either be due to something actually blocking motion of the knee (this can occur when a piece of cartilage wedges within the joint) or when pain prevents the patient from moving the knee. These two causes must be differentiated, as something physically caught in the joint should be evaluated in a timely manner. Often injecting the knee with numbing medication can help determine the cause of locking.
The stability of the knee is provided by the ligaments that connect the shin bone (tibia) to the thigh bone (femur). When the ligaments are stretched or torn, the knee may feel as though it is giving way beneath the patient. A sensation that the knee may give out from beneath you is a common symptom of ligament injury.
Swelling of the knee is common with several different knee problems. When there is swelling immediately after an injury (within an hour), the most common causes are an injury to the anterior cruciate ligament or a fracture of the top of the shin bone. When swelling develops gradually over hours to days, the injury is more likely a tear of the meniscus or a ligament sprain. Swelling that occurs without the presence of a known injury can be due to arthritis (common), gout (less common), or a joint infection (uncommon).
Treatment of knee pain depends entirely on the cause of the problem.
Some common treatments for knee pain are listed here.
Rest: The first treatment for most common conditions that cause knee pain is to rest the joint, and allow the acute inflammation to subside. Often this is the only step needed to relieve knee pain. If the symptoms are severe, crutches may be helpful as well.For ligament injury it may be required cast immobilization for some time.
Antibiotics:for infective pathology of knee.
Ice and Heat Application: Ice packs and heat pads are among the most commonly used treatments for knee pain. Cold fomentation is useful in acute injuries to relieve pain ane edema.Hot fomentation is useful in osteoarthiritis.
Stretching: Stretching the muscles and tendons that surround the joint can help with some causes of knee pain. A good routine should be established, and following some specific suggestions will help you on your way.
Physical Therapy: Physical therapy is an important aspect of treatment of almost all orthopedic conditions. Different techniques to increase strength, regain mobility, and help return patients to their pre-injury level of activity. 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.
Anti-Inflammatory Medication: Nonsteroidal anti-inflammatory medications, commonly referred to as NSAIDs, are some of the most commonly prescribed medications, especially for patients with knee pain caused by problems such as arthritis, bursitis, and tendonitis. 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.
Cortisone injections: Cortisone is a powerful medication that treats inflammation, and inflammation is a common problem in patients with knee pain. Discuss with your doctor the possible benefits of a cortisone injection for your condition.
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.
In meniscus injury if 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.
Total knee replacement is often the answer for people when x rays and other tests show joint damage; when moderate-to-severe, persistent pain does not improve adequately with nonsurgical treatment; and when the limited range of motion in their knee joint diminishes their quality of life.
Newer methods of treatment like ozone therapy,radiofrequency,proliferative therapy are being tried with successful results.
The deterioration of cartilage is gradual and there may be no symptoms in the early stages of knee osteoarthritis. Symptoms of knee osteoarthritis are stiffness (especially morning knee stiffness), knee pain that is aggravated by going up or down stairs, limitation in range of motion, a crunching feeling in the knee, and weakness of knee. The knee may be swollen but not red and hot.
(Symptoms such as diffuse pain in knee joint and crunching sound in the knee can be caused by “runners knee”, which is a common cause of knee pain in all age groups, including teens and young adults. Click here for more info on runners knee.)
Swelling of the knee may occur as a result of excess fluid accumulating within the knee joint. Damaged cartilage in the joint triggers inflammation of the joint lining (the synovium) and excess production of joint fluid (synovial fluid).
An accumulation of excess fluid within a joint is called joint effusion. In the knee, joint effusion is sometimes referred to as water on the knee. Knee joint effusion sometimes results in aBaker’s cyst.
In advanced cases, inflammation can also occur if bits of cartilage break off and float around inside the knee joint and cause irritation and inflammation of the soft tissue in the joint.
In advanced cases, there may be deformity of the joint. Cartilage has a limited ability to repair itself. The body compensates with the growth of extra bone, which results in visible enlargement of the joint.
Symptoms do not always correlate with the amount of damage to the joint. Symptoms can come and go for no apparent reason. This makes it difficult to assess whether or not a current treatment is working. Keeping the muscles that support the knee strong, keeping your weight down, and avoiding high impact activities can decrease the symptoms.
An x-ray may be helpful in diagnosing knee osteoarthritis. In a conventional x-ray the cartilage is invisible – how much cartilage has been lost is judged by the gap between the bones of the joint. A conventional x-ray can easily miss the early stages of knee osteoarthritis. And two radiologists may interpret the same x-rays differently. An MRI shows soft tissue (and bones) can also show the joint in motion
Diffraction Enhanced X-Ray Imaging (DEI) is a new type of x-ray that shows soft tissue as well as bone. The application of DEI to cartilage imaging was patented recently but is not yet in clinical use.
FACTORS increasing the risk of Knee Osteoarthritis
Muscle weakness in the quadriceps (muscles of the thigh that attach to the knee)
Injury to the joint
Repetitive movements (squatting, kneeling with heavy lifting)
Activities requiring repetitive joint impact – jogging
Exercise is beneficial for knee osteoarthritis: Strong leg muscles support the knee and absorb shock before it gets to the knee. Exercising the quad muscles increase circulation in the knee joint and has been shown to stimulate beneficial biochemical changes in the joint fluid of the knee, improving its lubricating properties. Exercise also improves the range of motion of the knee. However, in patients with knee osteoarthritis who have misaligned knees, over-strengthening of the quads can sometimes make matters worse. A doctor or physical therapist (physiotherapist) can determine whether or not your knees are properly aligned and which exercises would be most beneficial.
Exercising in water, especially warm water, has may benefits for those with joint problems.
Heat and Cold:
Applying heat to the knee joint reduces stiffness and pain by increasing blood flow. The heat is also a comforting distraction from the knee pain. DO NOT apply heat to an inflamed joint. Usually, inflammation is not present in the early stages of knee osteoarthritis.
Apply heat for 20 – 30 minutes at a time, waiting at least an hour between each application to prevent overheating of tissues. Dry or moist heat is beneficial but moist heat penetrates the tissues more quickly, and penetrates more deeply than dry.
For moist heat, you can use a towel soaked in warm water but it may cool off fairly quickly. An alternative is to place a moistened towel between your knee and a hot water bottle. There are also moist heating wraps available commercially.
Do not use rubs and heat at the same time as a burn may occur.
Cold reduces knee inflammation and knee pain by constricting the blood vessels. Apply ice wrapped in cloth to an inflamed joint for 15 – 20 minutes every 3 or 4 hours. Do not ice for longer than 20 minutes at one time to avoid frostbite. Moist cold (Place a wet towel between the skin and an ice pack for moist cold) penetrates more deeply and quickly than dry cold.
*If you have circulation problems or nerve damage do not use hot or cold therapies. (Unless a physician says it is safe for you)
Being overweight places extra stress on the knee, a weight-bearing joint. Even 10 pounds can make a big difference in the symptoms of knee osteoarthritis.
Though the reason it works is unclear, knee taping has been shown to significantly reduce knee pain in patients with knee osteoarthritis. There are different taping techniques that a physical therapist (physiotherapist) can teach a patient. Sometimes the skin can become irritated from the tape.
Used For Certain Cases of Knee Osteoarthritis: Unloader braces are designed to provide knee pain relief for those with knee osteoarthritis. They are very expensive but some health insurance plans cover them. Quite frequently, the cartilage is more worn out of one side of the knee joint, causing the thighbone to sit on an angle and the thighbone to rub against the shinbone on the worn out side. Unloader braces take off the load (pressure) on a knee joint by changing the angle of the knee joint. By changing the angle of the knee joint, a space between the thighbone and shinbone is created, relieving knee pain and increasing range of motion. An x-ray can determine if the space between the thighbone and shinbone is angled. A doctor or physical therapist (physiotherapist) can assess whether or not an unloaders knee brace would be helpful in a particular case and recommend the appropriate knee brace.
This therapy involves stimulating nerve endings with low voltage electric impulses through electrodes attached to the body at the site of the pain. It relieves pain in some patients.
Joint fluid contains hyaluronic acid (hyaluronate), which makes the fluid thick and sticky. In osteoarthritis, the production of hyaluronic acid decreases and its concentration in the joint fluid is reduced. This results in a thinner fluid, with reduced ability to lubricate the joint and to absorb shock.
Viscosupplementation Treatment consists of a series of 3 injections over 3 weeks. A fluid (hyaluronates) similar to normal joint fluid is injected into your knee joint to lubricate and cushion it. (In cases of knee osteoarthritis, the normal gel-like joint fluid – synovial fluid – becomes thinner) The knee pain relief usually lasts for 6 – 9 months. If the symptoms recur, the injections can be repeated. The success rate is very high in milder cases, and even in the most severe cases the success rate is over half.
Hyalgan is the first FDA-approved hyaluronan therapy (viscosupplementation) in the US for Osteoarthritis of the knee. Other FDA-approved hyaluronates for hyaluronan therapy includesSynvisc, Supartz, and Orthovisc.
Arthoscopic surgery: Non-invasive surgery, a camera attached to video monitor is inserted through small incision. This is minor surgery, usually performed on an outpatient basis. Rough damaged cartilage can be shaved; bone spurs can be removed, loose bits of cartilage cleaned out.
Unfortunately, this is Not an option for those with knee osteoarthritis. This can only be done only for small defects in the articular cartilage, not for the more common diffuse damage seen in knee osteoarthritis. A cartilage transplant is done by taking small pieces of cartilage from an area of the knee where there is minimum weight bearing, growing cartilage outside the body and transplanting in back into the damaged part can repair minor defects.