Knees

Get strong, stay flexible. Weak muscles are a leading cause of knee injuries. You'll benefit from building up your quadriceps and hamstrings, the muscles on the front and back of your thighs that help support your knees. Balance and stability training helps the muscles around your knees work together more effectively.

knees

Arthritis. Osteoarthritis is the most common type of arthritis that affects the knee. Osteoarthritis is a degenerative process where the cartilage in the joint gradually wears away. It often affects middle-age and older people. Osteoarthritis may be caused by excess stress on the joint such as repeated injury or being overweight. Rheumatoid arthritis can also affect the knees by causing the joint to become inflamed and by destroying the knee cartilage. Rheumatoid arthritis often affects persons at an earlier age than osteoarthritis.

Cartilage is a thin, elastic tissue that protects the bone and makes certain that the joint surfaces can slide easily over each other. Cartilage ensures supple knee movement. There are two types of joint cartilage in the knees: fibrous cartilage (the meniscus) and hyaline cartilage. Fibrous cartilage has tensile strength and can resist pressure. Hyaline cartilage covers the surface along which the joints move. Collagen fibres within the articular cartilage have been described by Benninghoff as arising from the subchondral bone in a radial manner, building so called Gothic arches. On the surface of the cartilage these fibres appear in a tangential orientation and increase the abrasion resistance. There are no blood vessels inside of the hyaline cartilage, the alimentation is performed per diffusion. Synovial fluid and the subchondral bone marrow serve both as nutrition sources for the hyaline cartilage. Lack of at least one source induces a degeneration. Cartilage will wear over the years. Cartilage has a very limited capacity for self-restoration. The newly formed tissue will generally consist of a large part of fibrous cartilage of lesser quality than the original hyaline cartilage. As a result, new cracks and tears will form in the cartilage over time.[14]

Any kind of work during which the knees undergo heavy stress may also be detrimental to cartilage. This is especially the case in professions in which people frequently have to walk, lift, or squat. Other causes of pain may be excessive on, and wear off, the knees, in combination with such things as muscle weakness and overweight.

In sports that place great pressure on the knees, especially with twisting forces, it is common to tear one or more ligaments or cartilages. Some of the most common knee injuries are those to the medial side: medial knee injuries.[29]

We found no evidence of an independent association between the presence of knee effusion and meniscal extrusion in our study sample. In a previous study, Miller et al (34) demonstrated that knee effusion is associated with medial meniscal extrusion. The authors hypothesized that distention of the joint capsule, which is firmly attached to the medial meniscus, medially would be responsible for meniscal displacement. This would also explain why they did not find a significant association between knee effusion and meniscal extrusion in the lateral compartment, because joint fluid tends to collect in the lax and yielding meniscal-capsular attachments. However, the relationships demonstrated in their study did not take into account all potential factors that might lead to extrusion (no adjustments were performed), so we do not know whether knee effusion is independently associated with medial meniscal extrusion. In our study sample, after adjusting for all covariates considered, knee effusion was not independently associated with meniscal extrusion in either compartment. Of all knees exhibiting effusion at baseline, only 4.8% had grade 3 effusion (> 66% of maximal potential distension), which might help explain why effusion was not associated with meniscal extrusion in our study.

The changes in the gut microbiomes of the mice coincided with signs of body-wide inflammation, including in their knees where the researchers induced osteoarthritis with a meniscal tear, a common athletic injury known to cause osteoarthritis. Compared to lean mice, osteoarthritis progressed much more quickly in the obese mice, with nearly all of their cartilage disappearing within 12 weeks of the tear.

Paul Rider runs on Mulholland Drive in Los Angeles, March 25, 2011. Researchers say a moderate running regimen is actually beneficial for the joints of people with healthy knees. Dennis J. Provost for NPR hide caption

Yes, it's true: Jogging, long thought to hurt knees with all that pounding and rattling around, may actually be beneficial for the complex and critical joint. There are caveats, though, especially for people who have suffered significant knee injury or are overweight. But for the most part, researchers say, jogging for your health seems like a good idea.

David Felson, a researcher and epidemiologist at Boston University School of Medicine, says past concern about jogging and knees centered on the continuous impact of the foot to the ground and suggestion that it caused degeneration of the knee and the onset of osteoarthritis. But when researchers actually studied the impact of running on knees, he says, that's not what they found.

"We know from many long-term studies that running doesn't appear to cause much damage to the knees," he says. "When we look at people with knee arthritis, we don't find much of a previous history of running, and when we look at runners and follow them over time, we don't find that their risk of developing osteoarthritis is any more than expected." Both types of studies agree, says Felson, that recreational running doesn't increase the risk of arthritis.

Long-term studies show that running doesn't appear to damage knees. But researchers caution that if you've had knee surgery or if you're more than 20 pounds overweight, you shouldn't jump right into an intensive running routine. Dennis J. Provost for NPR hide caption

"We wanted to answer the important question of whether, if you continued to run into your 50s and 60s and even 70s, you also ran the risk of damaging the knees," she says. The answer, she says: absolutely not. And there was an extra bonus: While enthusiasm for jogging seemed to diminish as people hit their mid-60s, Lane says they were still more inclined than the non-joggers to get out and exercise.

Knock knees (genu valgum) is a condition in which the knees tilt inward while the ankles remain spaced apart. The condition is slightly more common in girls, though boys can develop it too.

Many children develop knock knees during early childhood. As they begin to walk, an inward tilt at the knees can help children balance. This stance also helps if one or both of their feet roll inward or turn outward.

Doctors do not usually order x-rays for children within the normal age range for knock knees if they have no problem walking, running, or playing, and have typical appearing legs. This avoids exposing the child to unnecessary radiation.

In most cases, children with knock knees do not need medical treatment. The most common treatment for children between 2 and 5 years old is close observation. Up to 99 percent of children with knock knees grow out of the condition by the time they turn 7. Children do not need to avoid physical activity, wear braces or special shoes, or do any special exercises.

If your child has severe, unresolved knock knees, their doctor will first determine if this is part of another underlying condition. If so, treatment will focus on treating the underlying condition. For example, many cases of rickets can be treated with vitamin D and calcium supplementation.

Guided growth surgery corrects knock knees by slowing the growth on the bent side of the bone so the other side can catch up. The surgeon implants small metal devices on the inner side of the growth plates around the knees. The outer side of the knees will continue to grow, causing the legs to grow straighter.

Osteotomy surgery can correct more severe deformities or knock knees that do not get better on their own by the time a child has finished growing. The goal of this procedure is to straighten the legs by changing the angle of the bones. A surgeon does this by cutting and realigning the bone above or below the knee.

The vast majority of children with knock knees get better without treatment and have a very positive long-term outlook. For children who have surgery for severe forms of the condition, the outlook is also excellent. The surgical and non-surgical procedures are quite safe and children's bones usually heal faster and more reliably than adults.

As a national and international orthopedics referral center, our Orthopedic Center has vast experience managing all aspects of knock knees. Our Lower Extremity Program offers comprehensive assessment, diagnosis, and treatment for children and young adults with conditions affecting their lower limbs. We have extensive experience treating disorders of the feet, ankles, knees, legs, and hips. Whether the patient is an infant, child, or adolescent, our goal is to help our patients live full, independent lives.

Knee pain is the most common symptom of osteoarthritis in the knee, making it painful for you to jog, run, climb stairs or kneel. It can also make your knees feel stiff or swollen. Over time, osteoarthritis of the knee can change the shape of your knee joint, making your joint feel unstable or wobbly.

The Arthritis Foundation state that exercise may be the most effective way to treat osteoarthritis without surgery, while the American Academy of Orthopaedic Surgeons note that strong and flexible muscles can keep knees healthy and prevent injury.

Knee strengthening exercises do not affect the knee joint directly, but they strengthen the muscles surrounding it. Strong muscles in the legs can help provide support for the knees. This support may alleviate pressure and strain on these joints, which can relieve pain and help a person be more active. 041b061a72