FAQ Category: Knee

A small study was done at the Rehab Institute of Chicago (RIC) using an electric goniometer after total knee replacement (TKA). A goniometer is used to measure joint motion. Most often a physical therapist uses a hand-held goniometer to measure the joint
motion manually.

The electric unit was meant to help patients with problems that could delay their recovery. Some had severe rheumatoid arthritis. Others had social or psychologic problems slowing them down. The device is still under investigation and not on the market for
general use yet.

You may be a good candidate for future studies. To contact RIC call 1-800-354-REHAB (1-312-238-1000) or visit their website on-line at
http://www.ric.org.

You may want to discuss this with your therapist. It’s best to work out a schedule that will enable you to exercise throughout the day at regular intervals. It’s understood that
early on in the rehab program patients are still recovering from the operation. This is also the crucial time for getting as much motion as possible.

Maintain a good diet and get plenty of sleep at night. Check with your doctor about your fatigue level if it seems excessive. It may be drug-induced or you could have some other medical reason for it.

Some patients choose two times during the day when they set aside what they are doing and carry out their exercises. Others prefer to set a timer and do one or two exercises every hour. Your therapist will be able to advise you on which is best for you depending on how much joint motion you have.

Find out what your joint motion is and how much you need to increase it for each day, week, and over the next month. Make that your goal and work towards it everyday.

It sounds like the therapist was measuring joint position sense. This is called proprioception. The joint is bent or straightened by the therapist and the patient tells when movement is first felt.

Right now researchers are trying to find out more about proprioception. What’s normal? Does it change as we get older? Is it the same for men and women? What happens when the joint becomes arthritic? Scientists hope to find an exercise program to restore
proprioception–maybe even reverse the effects of arthritis.

Not likely or you would probably have had knee problems at a young age. There are two ligaments that criss-cross inside the knee joint–the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). Together, these ligaments help hold the joint together and keep it stable during movement.

Torn or damaged knee ligaments can occur with trauma, injury, or age. Many patients having a total knee replacement have a deficient ACL. An earlier injury and torn ligament often lead to knee arthritis. Less commonly, the PCL is involved.

It’s rare to have both ligaments missing at the same time. This is a sign of severe injury, probably more than one–since the mechanism of injury is different for each one.

The sense of joint position is called proprioception. Research shows that proprioception is altered with osteoarthritis. The more severe the patient’s symptoms, the longer it takes for the knee to register its position.

Scientists aren’t sure if the arthritic changes cause the change in joint position sense or the other way around. There could be other causes for your problem such as loss of joint motion and muscle weakness. It might be a good idea to have this checked out before a misstep causes a serious problem.

The meniscus is a C-shaped piece of cartilage in the knee joint. It helps the joint move smoothly and acts as a shock absorber. It can also help transfer the load through the joint.

The knee joint has two menisci (plural), the medial (inner portion) and lateral (outer portion). When the outer edge of the cartilage is torn, it looks like a crescent-shaped moon or bucket handle.

At one time it was thought the meniscus didn’t have any real function. A tear would result in surgery to remove the whole thing. Later scientists found this treatment led to joint damage and early arthritis. Now most surgeons prefer to repair the tear or just take out the torn section.

There are two menisci between the shinbone (tibia) and thighbone (femur) in the knee joint. (Menisci is plural for meniscus.) The C-shaped medial meniscus is on the inside part of the knee, closest to your other knee. (Medial means closer to the
middle of the body.) The U-shaped lateral meniscus is on the outer half of the knee joint. (Lateral means further out from the center of the body.)

The meniscus is thin but has a wedge shape when viewed from the side. The outer edge of the meniscus is thicker than the central part. There’s more blood supply to the outer edge. The inside or central part of the meniscus doesn’t have a blood supply. It gets its
nutrients from the synovial fluid inside the joint.

The thicker wedge of the medial meniscus is attached to the joint capsule and ligaments. The thinner central portion is free to move in and out slightly during normal knee motion. Both parts of the meniscus work to give the knee joint a smooth fit and easy movement. Both functions are needed for the kinds of loads the knee holds up under.

Without a lot of blood vessels, injury results in pain but doesn’t cause swelling. A locking sensation or even “giving way” of the leg can occur when the meniscus is torn.

The most likely cause for this is a torn meniscus. If the outer curve of the meniscus is torn, the inner portion can get stuck in the notch or opening for the ligaments. The terms “trick knee” or “locked knee” are used to describe the condition.

Usually the knee can still bend but can’t straighten. Sometimes the inner portion of the meniscus can slip back into place. Then the knee seems to work fine again. A minor injury can displace the torn cartilage again.

Most surgeons advise repairing a small tear before another injury tears it completely. Have an orthopedic doctor take a look soon.

Knee function can be measured and assessed in several ways. Some patients just ease their way back into sports and activities based on how their symptoms and level of confidence. There’s actually a Knee Ligament Rating System your doctor can use to help answer your
question. There are four parts: current sports activity level, ability to engage in sports, function, and amount of pain, swelling, and giving way.

The patient and the doctor each answer questions. Each part is rated from zero to 100 percent with 100 percent being the maximum function or best score. Researchers report
it’s a reliable grading system that helps predict results better than other tools or rating systems.

Check with your physician about using this tool for your purposes. You may get just as good information from the physician’s tests and exam, but confirmation of the findings is
always reassuring too.

Runners and hikers have all noticed that stiffness is worse the day after going downhill compared to going up. Going downhill puts much more strain on the muscle fibers and connective tissue compared with moving over a flat route. Downhill running can be damaging because of the greater eccentric muscle contractions that occur. Let me explain.

When your foot hits the ground, the muscles in the thigh contract to support you. But the nature of the downhill action is such that although the muscle is contracting, it’s forced to lengthen at the same time. Contracting while lengthening a muscle at the same
time is called an eccentric contraction. It can cause trauma and damage to muscle fibers.

Trauma to the muscles and connective tissue around the muscles causes tiny tears of the tissue fibers. Stiffness occurs as a result of muscle damage and breakdown of nearby connective tissue.

Maybe nothing. At the time of your anterior cruciate ligament (ACL) reconstruction, your surgeon advised you based on the research findings available. Today’s studies still show
that cartilage wear and tear is greater when the knee ligaments are damaged or loose. An unstable knee can’t absorb the forces and loads put on it. The eventual result is arthritis.

Up until now it was thought that just restoring the right amount of forward and backward
“give” in the joint was enough. A recent study from the Bone and Joint Center at the Henry Ford Health System suggests it’s more than that.

Using high-speed digital imaging they were able to film, map, and measure joint motion after ACL reconstruction. Each patient’s normal knee was measured too and compared to the side with an ACL reconstruction. They found the forward and backward slide of the joint was restored, but all the reconstructed knees were rotated outward and pulled in toward the midline more than normal.

There’s no clear proof that ACL repair prevents arthritis. It may be that other factors are at work here. Surgeons will keep looking for the perfect balance of reconstruction and rehab to give future ACL patients the best outcome.

Men and women have the same sex hormones, just in different amounts. Men have 10 times more testosterone than women. Women have more estrogen. But women do have some testosterone and men have small amounts of estrogen.

Anterior cruciate ligament (ACL) injuries have actually been linked to changes in hormones. Each hormone plays some role in ligament laxity. Combined together the effect is much greater.

A recent study showed ACL injuries occur more often in women with higher levels of testosterone. However if testosterone is the hormone that increases joint laxity then men would be expected to have more joint injuries.

It’s likely the hormones acting together makes a difference. More study is needed to find out more about this.

Physical therapy often begins within a week of the first visit with the doctor. Sometimes there’s a longer wait time between injury and the start of rehab. Most research shows early rehab is best. The therapist can help reduce swelling in those early days.

After injury patients stop putting weight on the leg and stop moving the knee. The result is a very quick loss of muscle strength. The muscle will start to atrophy in the first two weeks. This sets up a complete change in the way the knee moves. Nerve messages to
the muscle change. The muscle loses its normal activity pattern and becomes
dyskinetic.

Dyskinesia refers to altered muscle activity patterns and incoordination. These types of changes can result in another knee injury. It’s a good idea to see the therapist as soon as possible.

Keep exercising, even if at a low level. Stay at it and don’t be put off by the pain. Without use the muscles weaken and atrophy quickly. They can’t contract and relax normally.

The most remarkable thing is how quickly recovery can happen. The muscles will respond to your exercise program. Patients say that looking back they are amazed by how quickly the muscles shut down after the injury and then again after surgery. They also comment on how
quickly the muscles responded to therapy.

It is a long road. Here’s some simple, but good advice:

You may not need surgery just yet. Studies show changes occur in the way the quadriceps (thigh) muscle works after ACL injury. Just as you report, the vastus lateralis (VL)–the part of the muscle along the outside of the thigh–is affected the most.

One group of researchers studying this problem tried using a knee brace to delay the VL response. It doesn’t work for everyone, but it may be worth a try. In that study about 70 percent of the patients had a favorable response by using a functional knee brace.

Rehab and exercises to improve quadriceps control is very important. Biofeedback may be very useful in this program. Challenging your balance in all directions is also helpful. Ask your physical therapist for more help in these areas.

There’s nothing wrong with giving family members information. This will help them make difficult decisions. Ask his doctor for medical information that answers common questions and addresses typical fears.

It may be best not to rely on the opinions and experiences of friends and family. Each patient has his or her own unique needs. There may be other medical issues to consider such as diabetes, high blood pressure, or osteoporosis.

Studies show the decision is best made by the patient with his or her doctor’s input. Patients who make their own choices are more confident in those decisions. Many patients delay the operation because they are unsure there’s enough support and services to help them through the first few months. Families can help loved ones look at these concerns and plan accordingly.

You may not need to go that far. The Cincinnati Sports Medicine and Orthopaedic Center in Cincinnati, Ohio, is right in your backyard. Dr. Frank Noyes and his associates have done
many studies of the knee.

They’ve recently published the results of research on the topic of meniscal transplantation. A group of young adults with severely damaged cartilage were included. It’s the first time meniscus transplant with bone graft was used.

The long-term results aren’t known but short-term effects were good. Patients had less knee pain and more function. Some were able to return to light sports. The surgeons advised against high impact or strenuous athletics.

Meniscal transplantation is in the works. It’s not done by all surgeons but it’s being studied by some. There are many questions left to answer before using this operation on a routine basis.

For example how much meniscus is really needed? What’s the best way to prepare donated tissue? How should it be put into the knee? How long does it last? What problems come up
soon after the operation compared to years later?

Right now this method of meniscal “repair” is used in young patients who have already had the entire meniscus taken out. Pain and joint degeneration are the basic criteria for this treatment method. There’s about a 60 percent success rate. This means about 40 percent (four out of 10) of patients have a failed transplantation.

You’ll need to see an orthopedic surgeon to answer this question. X-rays, MRS, and an exam will be used to test the knee. The location of the pain and what makes it better or worse will also help guide the surgeon.

X-rays show how wide the joint space is. A narrow space is a sign of cartilage thinning and early arthritis. An MRI can show the joint space, shape of the joint, and the status
of the cartilage.

The MRI signal can also be used to look at the height, width, and any movement of the meniscus. Even so it’s very hard to tell if the meniscus is torn just with an MRI. The doctor must rely on all these tests to make the diagnosis.

Researchers are looking at the link between women, hormones, and knee injuries. It’s clear that women have more injuries to the anterior cruciate ligament (ACL) than men. The differences in hormone levels are the most obvious place to look for the cause.

A recent study of this topic was done at the University of North Carolina Department of Exercise and Sports Sciences. The results showed a wide range in hormone levels from woman to woman. There was an equal amount of change across the monthly cycle.

Large changes in hormone levels can occur in a single day. It appears there’s also a time lag. In other words the effects of hormone changes don’t show up for three or four days.

Much more study is needed on this topic before it’s clear how to prevent these injuries. Taking hormones may not be the best answer.