FAQ Category: Knee

Proprioception is the ability of a joint to sense its position. When you move your knee from one position to another, sensors in the joint, ligaments, and muscles tell you how far you have moved the joint and where it is now. Sometimes this “position sense” is damaged after an ACL tear. This can lead to further injury.

How is proprioception measured? In one test, the physical therapist moves the uninjured leg to a certain position. Without looking, the patient places the injured leg in the same position. The two legs should be fairly closely matched. Another way to measure proprioception is to measure how long it takes the patient to detect motion when the therapist begins to move the leg.

There are specific exercises that can help restore joint proprioception. These are included in physical therapy whenever a joint has been injured, whether it’s the knee, ankle, shoulder, or another joint.

There have been several studies on this issue. The results are inconclusive. It seems that not everyone with ACL injuries or repairs has the type of changes you describe. For those who do, several studies show improved sense of joint position after wearing knee supports. Other studies show no difference after bracing.

A rehabilitation program is more likely to be beneficial. There are specific exercises physical therapists use to help improve the joint’s sense of position. If your knee feels unsteady (as if it might give out from underneath you), these exercises can still help. Check with your physical therapist about this.

The use of splints, elastic bandages, neoprene sleeves, and various braces for knee injuries is controversial. When to wear these devices and for how long are subjects of current research.

A proper diagnosis is the first step in knowing how to treat an injury. For example, elastic ace wraps are used for sprains to help reduce swelling in the first 24 hours. Knee support is sometimes recommended for anterior cruciate ligament injuries, especially if surgery is delayed. Talk with your doctor to find out whether extra support is necessary in your case.

Many studies have shown that ultrasound is the most accurate way to diagnose the kind of cyst you describe, known as a popliteal cyst. This test shows an empty chamber in the places where the sound waves make no echo.

Don’t be surprised if your doctor orders additional tests. Frequently, this type of cyst is the result of previous damage or trauma to the joint. It may be necessary to use other imaging studies to see these other injuries. This is important when planning surgery and other treatment.

Medical researchers have been able to show that these cysts form when there has been damage to the knee joint. Usually, this is a tear in the cartilage (meniscus) or damage to the bone from degenerative arthritis.

Medical advances have helped with the identification and treatment of these cysts. When diagnostic imaging such as ultrasonography became available, it was easier for doctors to see these cysts and look for a cause. Then knee surgery was improved by the development of arthroscopy. This method of looking inside the knee joint with a tiny camera gave doctors even more information.

It seems these cysts form when fluid squeezes out of the joint toward the back part of the knee in the area called the popliteal fossa, the indentation felt in the back part of the knee between the two hamstring tendons and the top part of the calf muscle.

Popliteal and Baker’s cysts are indeed the same thing. Both refer to a fluid-filled sac behind the knee. This was first observed and recorded by Dr. Baker (hence the name) in 1877.

Since that time, physicians have learned there is a channel that forms between the joint and the cyst. Fluid passes through this channel from the knee joint to create the cyst in the back of the knee.

It sounds like you may have torn one or both of the ligaments in your knee. There are several different methods to repair a knee injury of this type, but no agreement about which one works the best. When treating these injuries, the surgeon tries to repair as much of the damage as possible at one time. Sometimes more than one operation is required.

The technique mentioned (using the semitendinous tendon of the hamstring muscle) has several advantages. First, when using your own tendon, it is not necessary to obtain bone or tissue from someone else. This eliminates complications from grafting. Second, the hamstring tendon travels in the same direction as a muscle called the popliteus. This gives the knee a better mechanical advantage. Third, this technique changes the way the surgeon drills through one of the bones to attach the graft. This helps prevent fractures from the drilling process.

There are several other advantages due to the fact that this surgical technique helps prevent backward movement of the lower leg bone (tibia) on the upper leg bone (femur). There are always possible problems after surgery. Ask the doctor to review these with you before making a decision.

Yes. High-velocity or high-energy accidents in contact sports can cause damage to both ligaments in the knee. This can also happen in car accidents if the knee impacts the dashboard. Injuring both ligaments makes the knee very unstable. This causes problems walking and using the knee.

With this much damage, surgery is the preferred treatment. The surgeon will repair as much as possible at one time, but these are time-consuming operations. Sometimes a second surgery is needed to finish the repair. The first and most important surgery is to repair the posterior cruciate ligament and surrounding structures. These must be repaired at the same time because these tissues work together to help stabilize the knee.

Many knee injuries are fairly straightforward. A few tests and some follow-up imaging studies to confirm the diagnosis are all that’s needed. Other injuries are not so clear. For example, if both ligaments inside the knee are torn, the doctor will need to look for different problems than if just one ligament is damaged.

Instability in the back and outside of the knee joint, called posterolateral instability, can be very difficult to recognize. This is especially true during the early phase of the injury. The kind of surgery needed to repair the knee depends on an accurate diagnosis. Thus, a large number of tests as well as X-rays or MRIs are often necessary.

The surgeon uses an arthroscope to look inside the knee joint without making any large incisions to actually open up the knee. After the arthroscopic examination, the remains of the torn ligament are usually cleared away.

Then, donor tissue is taken from a point near the knee to use as a replacement. Usually, a tendon just below the knee or along the inside edge of the knee is used. The surgeon prepares the donor tissue by shaping it and stitching it to get just the right amount of tension for its new use.

Using a special drill, the surgeon makes a tunnel through the shinbone (the tibia) in the lower leg. The donor tissue is passed through this tunnel and screwed or stapled in its new location. The knee is then tested by putting stress on the graft and making sure it is set at a tension that allows movement and relaxation of the joint.

The skin is closed. A dressing is applied to the wound, and a cold compress is placed around the knee to reduce swelling. Unless there are some unusual complications, patients go home the same day.

Biofeedback is a treatment used by physical therapists to help patients see what muscles they are using and how they are using them. There are different kinds of biofeedback. For example, holding a tiny thermometer in the hand can record skin temperature. By thinking about breathing and imagining a warm place, it is possible to increase the blood flow to the fingers. This increases the temperature of the skin, and the thermometer records the increase on a computer screen.

Likewise, muscle activity can be measured with electrodes placed on the skin. These record the electrical impulses of the muscles when they contract. By watching signals on the computer screen or hearing signals, it is possible to increase or decrease muscle contractions. This form of biofeedback is called electromyographic biofeedback.

Biofeedback treatment is used to help people improve their ability to control their own muscles. Once the electrodes are in place, the therapist will teach the patient how to contract and hold one muscle while relaxing another. When the muscles function properly, the patella moves normally, and pain is reduced or eliminated.

Chondromalacia, or patellofemoral pain syndrome, occurs when the cartilage on the back of the kneecap (patella) becomes cracked and worn. The rough surface “catches” on the bones underneath, causing painful symptoms. The exact cause of this problem is unknown. Anything that pulls the patella off the center of the knee can be part of the problem.

The muscle in front of the thigh (quadriceps) is supposed to help hold the patella in the middle. Pain or injury can lead to a loss of control in this muscle. As a result, the patella gets off track. This is a major cause of chondromalacia of the patella.

Exercises to strengthen the quadriceps and other measures to help the patella track normally can help. Two-thirds of all patients with this problem have an overall positive result with this kind of program.

I have been diagnosed with chondromalacia of the knee. What is this?

Chondromalacia, sometimes referred to as “patellofemoral pain syndrome,” is a common problem in young adults. When the kneecap (patella) moves up and down, it usually follows a track that runs along the bones underneath. If the patella is not in the center, it starts to move off the track. This can cause wear and tear of the cartilage behind the knee. The back of the patella becomes rough and catches on the bone. This produces a crunching sound called crepitus. When this happens, pain, aching, and muscle weakness can develop.

Doctors use the results of physical examinations and X-rays to make this decision. A loose piece of bone or severe malalignment in the knee (as seen on X-rays) point to the need for surgery.

Usually after the kneecap (patella) is dislocated the first time, treatment with a physical therapist is recommended. The therapist will prescribe strengthening exercises and help you retrain your movements to keep the patella in place. If you still have pain, swelling, difficulty climbing stairs or doing sports, surgery may be required.

Ask your doctor if a more conservative approach such as physical therapy could help you.

Conservative treatments are those that do not involve surgery. When the knee bends and straightens, the kneecap, or patella, moves up and down in a straight track over the knee joint. If the fibers holding the patella in place are torn or damaged from injury, the patella can get pulled to the outside. If the patella moves completely off its track, it becomes dislocated.

Sometimes exercises to strengthen the muscles around the knee can help with this problem. Learning how to stand and use the leg with good alignment and proper patellar tracking may help. Sometimes a soft brace or knee support helps hold the patella in place while you retrain the muscles and change the way the patella moves.

However, when the patella dislocates over and over, conservative treatment is not likely to help. Surgery to repair the surrounding structures and realign the patella may be necessary.

Although removing part of the lateral meniscus in the knee (partial meniscectomy) has an excellent result in most people, there are exceptions. About one-third of these surgeries result in symptoms like those you describe. There may be limping, difficulty climbing stairs, and trouble squatting. The knee can also lock up in one position.

Sometimes these problems occur in older adults who have the surgery. Problems of this sort are also more common in people who are overweight. Losing weight can help take pressure off the joint. Sometimes an exercise program to strengthen the knee can improve the function of the knee while decreasing pain and swelling. Talk to your doctor about these possibilities.

Maximum improvement from removing the meniscus occurs between four months and two years after surgery. At least half of these patients are able to return to their pre-injury activity levels. Although these results are considered good, physicians are trying to find ways to save the meniscus by repairing–instead of removing it. This may lead to even better long-term results.

The meniscus or cartilage in the knee can be damaged from an injury or from the wear and tear of use and age. You may be seeing the result of trauma in one knee and the effects of degeneration in the other.

There are several tests physicians use to check the integrity or strength of the repaired ligament. One of these is the pivot-shift test, in which the doctor applies pressure to the lower leg just below the knee. A “tight” joint will not shift or move with this test.

Your sense that the leg is not steady or stable enough to hold you may be caused by muscle weakness. When the replacement tissue for the torn ligament is taken from below the kneecap, the quadriceps muscle on the front of the thigh may lose strength. You may need some additional strengthening exercises. Contact your physical therapist for a follow-up evaluation.

Not necessarily. It’s likely your friend’s ACL was severely damaged. Your doctor may have determined that your ligament was only mildly torn or stretched out. In that case, physical therapy treatments can be used to help improve your knee function.

Your doctor and physical therapist will watch to see if you get full knee motion and strength. If your pain and swelling go away and your knee feels stable and strong, you may be able to return to competition without knee surgery.