FAQ Category: Knee

Hard to say. Doctors really don’t know why this happens to some people. Some think it could have to do with genetics. Others believe it could be from a previous knee injury. People who have endocrine imbalances are also prone to this condition. Finally, experts believe it can show up in later life if there was a problem during the time when the growth plate in the knee bones was changing from cartilage into bone.

This depends on the type of surgery you’ll need and the recommendations of your doctor. It also depends on the success of the surgery. Even though many people get good results from surgery and are able to resume activities without other problems, you may be advised to choose activities that prevent extra strain where the articular cartilage was replaced. If an allograft surgery is done (one using donated tissue), most doctors recommend that their patients not return to high-level sports or recreational activities.

Yes. New surgical techniques have been developed that allow doctors to replace cartilage. However, some of these procedures are still in the experimental stage, and most of the newer techniques are only helpful when the problem is limited to a small area. When the area to be filled in is too large or the arthritis is too far advanced, other strategies are used.

The smooth surfaces of cartilage in synovial joints like the knee allow for repeated movements with minimal wear and friction. If the joint is healthy to begin with, kept in good alignment, and free of injury, it is not likely that repeated movements would cause problems.

A recent study compared the thickness in knee cartilage between a group of triathletes and a group of people who had been inactive all their lives. There were hardly any differences at all. The knee cartilage of the triathletes did not appear to be negatively affected, despite the intense impact and repeated joint-loading commonly associated with this activity.

It’s easier to move and exercise in a pool. The buoyancy of the water lends resistance, and helps you walk and move with less stress on your knees. The warmth of the water can help muscles relax, improve circulation, and ease soreness. Exercising in a pool is a great way to keep your muscles and joints strong and limber, without flaring up problems with knee osteoarthritis.

The meniscus is a tough, rubbery pad between the shinbone (tibia) and thighbone (femur) in the knee joint. There are actually two menisci inside the knee. The C-shaped medial meniscus is on the inside part of the knee, closest to your other knee. The U-shaped lateral meniscus is on the outer half of the knee joint. 

The meniscus protects the knee by spreading out pressure and forces on the knee. Without it, these forces are concentrated to a smaller area, which puts more wear and tear on the joint. The meniscus also improves knee stability by forming a socket on the top surface of the tibia. This socket gives added support where the femur bone joins the knee.

Possibly. Surgeons are exploring ways to replace the meniscus after it has been removed. One way is to take the meniscus from a cadaver knee (an “allograft”) to replace the patient’s meniscus. This is a new procedure, but so far the results are promising. An average of five years after meniscal transplant, patients in a recent study had better physical and social functioning–and less pain.

Unfortunately, the chances of retearing the transplanted meniscus are as high as 36 percent. In the case of a retear, another surgery may be needed. Yet even those requiring another surgery to fix torn transplants tend to report improvement. Talk with your doctor to see whether this procedure is an option for you.

In a recent study of this relatively new procedure, about a third of the transplants tore again after surgery. These menisci were then partly or totally removed.

Most of the retears were due to some sort of trauma. They didn’t happen for about two and a half years after surgery. Researchers think that transplants may be prone to further tears because their cell counts aren’t as high as the original menisci and the cells don’t produce as many nutrients.

Patients showed significant improvement with the transplant procedure, including those who needed more surgery to fix torn transplants. In general, patients had much less pain, and better physical and social functioning an average of five years later.

This study involved a fairly small number of transplants (22). More research is needed to look at the long-term results of this procedure.

A loose body is a piece of tissue from within a joint that has somehow become dislodged and floats freely in the joint. It can get caught between the joint when it moves, causing the joint to pop, click, catch, or even lock up.

There are several conditions in the knee that can be sources of a loose body. A loose body can form if a section of the meniscus has torn loose, either from trauma or degeneration. A bone chip from a fracture can also become a loose body. Another possible source for a loose body is osteochondritis dessicans (OCD), a condition in which a piece of cartilage and the underlying bone have been damaged. In some cases, the damaged fragment separates from the bone and floats freely within the joint.

With these exercises, the foot is kept on the ground while movement and resistance take place in the joints and muscles above. These types of exercises are important because they are akin to the activities we do every day. For example, a partial squat exercise is the same action as lowering yourself onto a chair or couch. A leg press is a lot like the action of going up a stair or step. These exercises add strength and stability around the muscles and joints of the hip and leg.

You’re right that nerves signaling pain don’t connect to articular cartilage. So why the pain? Swelling in or around the joint could be one explanation. This can put pressure on the nerves within the knee joint that do signal pain. If the articular cartilage is torn completely through to the bone below it, then the pressure over the unprotected part of the bone could be registering pain because these tissues in the bone have a nerve supply.

Knee arthroscopy may be the most common orthopedic procedure done today. It is a highly safe and reliable way to locate the source of knee pain. Researchers estimate that it is accurate over 90 percent of the time. Also, arthroscopy is more readily available to most patients than some other diagnostic procedures, such as MRI.

While MRI may be less invasive, it’s also more costly and, in some cases, harder to get. Some doctors worry that MRI may be less accurate than arthroscopy.

If both kinds of procedures are available to you, you may want to ask your doctor whether he or she prefers one method over the other. It may be that, in your case, one of the procedures would do a better job of finding the source of your knee pain.

Some doctors have asked this very question. Yet it’s hard to beat the safeness and accuracy of knee arthroscopy. Other diagnostic procedures, such as MRI, tend to be more costly and less accurate. And in some clinics, patients have to wait longer to get them. For these reasons, knee arthroscopy remains the most popular way to look for the source of knee pain.

Even “normal” knee arthroscopy results–or finding no abnormality–may benefit the patient. A recent study found that patients with these results were doing much better a few years later. It’s possible that, after learning there were no abnormalities, patients learned to live with their symptoms. Or there could be some benefit from the procedure itself. In any case, a high percentage of “normal” knee arthroscopies may not be such a bad thing, after all.

It’s possible. Researchers followed 42 patients who had “normal” knee arthroscopy results. Sixty-four percent of the patients said they felt better three and a half years later. Only two percent felt worse. Sixty-eight percent said they had less pain, swelling, and knee locking and giving way.

The authors think that, once patients knew there were no abnormalities, they may have simply learned to live with their symptoms. Or there may be some benefit from the procedure itself. In any case, the authors conclude that “negative” knee arthroscopies–or those that come out “normal”–really aren’t so negative after all.

Standard treatment usually doesn’t involve surgery, but it depends on the PCL tear. If it’s a new tear without damage to bones or other ligaments, surgery may not be needed.

Most patients wear a splint and use crutches for a short period of time. Then they start physical therapy. It’s very important to restore thigh strength and range of movement. Patients who do these kinds of exercises can usually return to sports and other activities without limitations.

If the PCL tear is chronic or severe, surgery may be necessary. Doctors are developing new techniques to give patients better knee function after PCL surgery.

PCL injuries usually result from trauma, such as a car accident, or from sports. PCL injuries often happen when a force strikes the front of a bent knee. This may happen in a car, when the knee of the driver or front-seat passenger hits the dashboard on impact. It can also happen in contact sports such as football or wrestling. Hitting an opponent with the lower leg can drive the shin backward, tearing the PCL. Or a player may fall hard on a flexed knee.

PCL injuries don’t necessarily create a lot of pain or symptoms. However, it’s important that they’re detected through a careful physical exam. Chronic or untreated PCL injuries may lead to more severe knee problems down the line.

The cruciate ligaments are two ligaments that cross inside the knee joint. (“Cruciate” means cross). By connecting the thighbone (femur) with the shinbone (tibia), they help stabilize the knee. The ACL is in front. It protects the tibia from going too far forward in relation to the femur. The PCL crosses behind the ACL. It’s made up of two bands that work together to stabilize the knee when the lower leg is moving backward or rotating outward.

You hear more about the ACL because ACL injuries are more common. They also tend to result in more pain and symptoms than PCL injuries. However, recent studies suggest that PCL injuries may be more common than previously thought, accounting for roughly 20 percent of all knee injuries. Researchers have recently turned more of their attention to PCL injuries, to develop more effective treatments.

Research has shown that age-related changes like arthritis and cartilage damage can affect how satisfied patients are with this kind of surgery.

A study looked at the results of “partial meniscectomy” for patients over 70. For patients who had little or no arthritis or cartilage damage, the surgery had good results nearly 85 percent of the time. But only about half of the patients who had arthritis were satisfied with their results four years later. Sixty-nine percent of those who showed cartilage damage were satisfied.

Cartilage damage is usually evaluated during surgery. But arthritis can be seen in an X-ray. Your doctor can tell you about signs of arthritis in your knee and whether this may affect your results from surgery.

They certainly can. A recent study evaluated the results of this procedure (“partial meniscectomy”) in 91 patients with an average age of 74. More than two-thirds of the patients had less pain after the procedure. Roughly four years later, these patients hadn’t had more surgery. They said they were satisfied with their results and would choose the procedure again.

Of course, these results aren’t as good as those commonly seen in younger patients. In general, researchers think that patients over 70 should proceed with caution when it comes to knee surgery. This is especially true for patients who have more knee arthritis or cartilage damage.

Expectant mothers gain an average of 24 pounds during pregnancy. This weight begins to be distributed toward the front of the abdomen and is believed to cause changes in the way pregnant women walk. Research shows, however, that walking patterns don’t change that much over the course of pregnancy. The “waddling gait” believed to happen in late pregnancy isn’t that common.

In pregnant women, the muscles of the calf and hip are notably more active during walking. This is thought to contribute to problems of overuse in the leg muscles and may explain why you are feeling cramping in your calves. If your condition keeps giving you problems, let your doctor or physical therapist know.