What is knee pain?
Knee pain is a common problem that can originate in any of the bony structures compromising the knee joint (femur, tibia, fibula), the kneecap (patella), or the ligaments and cartilage (meniscus) of the knee. Knee pain can be aggravated by exercise, affected by the surrounding muscles and their movements, and be triggered by other problems (such as a foot injury). Knee pain can affect people of all ages, and home remedies can be helpful unless it becomes severe.
What are knee pain symptoms and signs?
The location of the knee pain can vary depending on which structure is involved. With infection or an inflammatory process, the whole knee might be swollen and painful, while a torn meniscus or fracture of a bone gives symptoms only in one specific location. A Baker cyst will usually cause pain in the back of the knee.
The severity of the joint pain can vary, from a minor ache to a severe and disabling pain.
Some of the other signs and symptoms that accompany knee pain are
difficulty walking due to instability of the knee,
limping due to discomfort,
difficulty walking up or down steps due to ligament damage,
locking of the knee (unable to bend the knee),
redness and swelling,
inability to extend the knee, and
shifting weight to the opposite knee and foot.
What causes knee pain?
Knee pain can be divided into three major categories:
Acute injury: such as a broken bone, torn ligament, or meniscal tear
Medical conditions: arthritis, infections
Chronic use/overuse conditions: osteoarthritis, patellar syndromes, tendinitis, and bursitis
Below is a list of some of the more common causes of knee pain. This is not an all-inclusive list but rather highlights a few common causes of knee pain in each of the above categories.
Acute knee injuries
Fractures: Direct trauma to the bony structure can cause one of the bones in the knee to break. This is usually a very obvious and painful knee injury. Most knee fractures are not only painful but will also interfere with the proper functioning of the knee (such as kneecap fracture) or make it very painful to bear weight (such as tibial plateau fracture). All fractures need immediate medical attention. Many fractures require significant force, and a thorough examination is performed to detect other injuries.
Ligament injuries: The most common injury is the ACL (anterior cruciate ligament) injury. This is often a sports-related injury due to a sudden stop and change in directions. The remaining ligaments (posterior cruciate ligament, lateral collateral ligament, and medial collateral ligament) are injured less frequently.
Meniscus injuries: The menisci (medial and lateral) are made of cartilage and act as shock absorbers between bones in the knee. Twisting the knee can injure the meniscus.
Dislocation: The knee joint can be dislocated, which is a medical emergency that requires immediate attention. Knee dislocation can compromise blood flow to the leg and have other related problems. This injury often occurs during a motor-vehicle accident when the knee hits the dashboard.
Rheumatoid arthritis is an autoimmune condition that can affect any joint in the body. It can cause severe pain and disability, as well as swelling.
With septic arthritis (infectious arthritis), the knee joint can become infected; this leads to pain, swelling, and fever. This condition requires antibiotics and drainage treatments as soon as possible.
Chronic use/overuse conditions
Patellar tendinitis is an inflammation of the tendons connecting the kneecap (patella) to the bone of the lower leg. Patellar tendinitis is a chronic condition often found in individuals repeating the same motion during exercise(such as runners and cyclists).
Patellofemoral pain syndrome is caused by degeneration or stress under the kneecap (patella) where it meets the thighbone (femur). Patellofemoral pain syndrome occurs in runners and cyclists.
Osteoarthritis: A wearing down of cartilage of the joint due to use and age
What are risk factors for knee pain?
Biomechanics: The knee joint is complicated in its operation and is used frequently throughout the day. Any change in the movement of the joint (leg-length difference, change in walking style due to back problems) can cause subtle changes and cause pain and injuries.
Excess weight: The stress on the knee joint is increased with excess weight. Obesity also increases the risk of osteoarthritis as the cartilage breaks down more rapidly.
Overuse during repetitive motions as are found during certain exercises (jogging, skiing) or work conditions (long periods of kneeling) can cause breakdown of cartilage and lead to pain.