FAQ Category: Knee

The ACL helps the knee joint to know what position it is in, a function called proprioception. This sense of joint position is very important for movement, joint stability, and function.

For example, when stepping down off a curb, the knee will bend and straighten just the right amount and at just the right speed to keep you from falling. Proprioception helps the knee joint do this. Joints, ligaments, and muscles have tiny sensors signaling the body about the joint’s position. These sensors also start the reflex that tells the muscles to contract. Without this function of the ACL, a person may feel as if the knee is unsteady or unable to keep the leg from collapsing.

Repairing the ACL usually means taking a piece of tendon from some other part of the knee and using it as a replacement for the ligament. Studies so far have shown that it takes a long time for this graft to get good blood supply and heal. Starting a vigorous exercise program too soon may result in a knee joint that is too “loose.” This can result in poor tennis performance and future injuries.

Patients usually start rehabilitation during the early weeks after surgery. During the first two weeks, the physical therapist will help you reduce the swelling and get full knee extension (straightening the knee). This will involve movement, positioning, and muscle contraction exercises. This is followed by a walking phase combined with the use of a stationary bicycle.

The therapist will prescribe balance and strengthening exercises, starting with the leg that wasn’t injured. This quickly progresses to include exercises for balance and control on the injured leg. The therapist will progress the program to include muscle strength, running, and jumping. Any specific movements necessary for tennis will be added as well.

Your doctor may be waiting for the inflammation to calm down. When a ligament is torn or partially torn, the body responds immediately to help the healing process. Sometimes this results in a lot of swelling in the area, with a loss of knee motion.

Your doctor may have you start a physical therapy program before surgery. Physical therapy is used to help reduce pain and swelling and improve knee motion and strength. Once the initial healing reaction has calmed down and you have your motion back, surgery can be scheduled. Research shows improved results when ACL surgery is postponed until these goals are achieved.

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.

When the anterior cruciate ligament (ACL) is strained, it becomes weak or “deficient” in holding the knee together. Without good ACL strength, the knee can be easily reinjured. This could happen while you are riding or during other activities.

Exercises on a special training disk retrain the ankle and knee to respond to quick movements. Stopping suddenly or changing directions quickly are examples of these types of movements. Balancing on the board or moving the board in many directions without losing your balance is important. This kind of activity improves the joint’s sense of direction and position.

Usually eight weeks of exercises on an exercise disk for 15 minutes each day are recommended. This is based on a series of studies done on athletes with ACL injuries. When you have finished your home program, the therapist can measure your strength and balance. This will help you decide if any further rehabilitation is necessary.

Q-angle–or quadriceps angle–is the angle between the quadriceps muscle (front of the thigh) and the patellar tendon (just below the kneecap). This angle can be determined using X-rays. More often, it is measured by placing the person flat on a table with the hips, knees, and feet in a neutral position. A line is drawn from the pelvic bone to the middle of the kneecap. A second line is drawn from the middle of the kneecap through the large bump on the shin (called the tibial tubercle). The angle formed by the crossing of these two lines is called the Q-angle.

Normally, the Q-angle is between 13 and 18 degrees when measured this way. Boys and men usually have smaller angles than girls and women. With a larger than normal Q-angle, the kneecap (patella) moves up and down over the knee joint in such a way that it can cause wear and tear of the cartilage. This causes crepitus, or the crunching feeling people describe when straightening the knee.

Ask your doctor about seeing a physical therapist. Using taping techniques, shoe inserts (orthotics), or muscle strengthening exercises, the therapist may be able to help your daughter learn how to keep the patella in the middle.  These measures can help reduce pain, swelling, and the crepitus sensation.

Certain movements place a large strain on the ligaments of the knee. These include stopping suddenly, or planting the foot on the ground and turning in a different direction. Soccer players are especially prone to injury of the anterior cruciate ligament (ACL) in the knee.

The hamstring muscles behind the thigh help protect the knee. How fast the hamstrings contract in response to sudden movements may help prevent injury to the knee. Quick response is a major principle of injury prevention for any athlete out on the field.

A total body response including the upper body, hip, knee, and ankle is also important for soccer players. A training program should include strength and balance training for these areas.

A new program for the prevention of ACL tears in soccer players has been published. It includes training the mechanisms in the knee and ankle to give these joints a sense of where they are and how they are moving. This training involves the use of a balance training board or disk.

The athlete is required to “balance” the board–or move it without losing balance. This action improves the body’s reaction time out on the field. This can help prevent knee injuries. Ask your trainer about this type of program if you aren’t already doing it.

Your definition of “tolerate” may be different from your doctor’s. Just because you can grin and bear the pain doesn’t mean your joint is able to tolerate the extra pressure when you’re up and about. You may need to ease up on your activity level, limit the amount of exercise you’re doing, and possibly use a cane or walker for a while. If you’re doing too much and your joint can’t tolerate it, you may end up with more pain and swelling. Use these symptoms as guides to what the joint can handle.

Doctors may put a needle inside the knee joint or into the bursa sac in front of and below the kneecap to find where the fluid is coming from. The needle can then be used to draw the fluid out. However, if the problem that is causing the extra fluid is not corrected, the fluid will probably come back. Unless there is an infection in the knee, there is no danger in leaving the fluid there because the body will gradually absorb it.

This usually describes pre-patellar bursitis. This is when fluid builds up in the bursa sac that lies in front of and below the kneecap. The front of the knee may look like a goose egg.

There are also conditions when the knee joint itself fills with fluid. A joint capsule encloses the bones of the knee joint. When the capsule fills with fluid, it may give the appearance of “water on the knee.” This can happen with problems like arthritis or infection.

An injury to the structures inside the knee can cause bleeding and swelling to fill the inside of the joint. In these instances, there will be fullness in the tissues of the knee, rather than simply a goose-egg appearance in the front of the knee.

Until recently, giving you guidance would be mere guesswork. Now we can say that your safest bet is to avoid any activities that cause a lot of impact on the knee, such as heavy jumping, lunging, and fast starts and stops. Research also shows that jogging and downhill walking put too much stress on the joint. Cycling and level walking are safer choices because the forces that happen during these activities are more evenly spread over the surface of the joint. Exercising in a pool is a good idea, too, because the water’s buoyancy allows you to move and exercise more easily, and there is less pressure on the joint.

Osteochondritis dessicans (OCD) of the knee is when a piece of bone just under the joint cartilage is injured and dies. The piece of bone and the cartilage above it may actually separate from the joint. When this happens, the fragment can float around inside the joint. Because it floats free, the fragment can get stuck in the joint, causing the knee to pop, click, or even lock up. 

Let swelling and pain be your guides. Pain is an indicator that something isn’t right. You may feel some discomfort with your exercises, but it should be “reasonable” discomfort. If you end up feeling a lot of pain that lasts more than one hour after exercise, you’re probably overdoing it. If you have pain with exercise or activity, you need to make some changes. Reduce the intensity, time, or repetitions of your exercise or activity. If you see swelling around your knee late in the day, this could also be a sign that you are overdoing it.

There aren’t any major nerves that pass by the area you’ve described. The feelings of weakness you have may be from a condition called “muscle inhibition.” When there is pain or swelling around a joint, the muscles in the area may shut down; that is, they become “inhibited.” The condition starts to improve once the pain and swelling are taken care of. If the problem continues, physical therapy treatments using muscle stimulators and exercise may be needed to get the muscles working correctly.

It is questionable whether you merely tore your medial collateral ligament (MCL) when you were first hurt. Had you only injured the MCL, chances are it would have scarred down and not given you much trouble.

From what you describe, it is more likely that you also stretched or tore the anterior cruciate ligament (ACL). In either case, you might not be a candidate for ligament surgery given your age. Instead, a surgeon specialist will probably want to have you use a brace and do exercise treatments. If these aren’t helpful, surgery might be a last resort. 

Age is one factor your surgeon will consider. So is activity. Your surgeon may treat you as he or she would a younger patient, given your level of activity.

If the tear is small and doesn’t cause swelling, you may be safe to exercise. But exercise probably won’t fix the tear. This is because joint cartilage does not have its own supply of blood and lymph vessels. This means the cartilage is not able to heal on its own. If the tear goes all the way down to the bone, you may not require surgery. But again, your knee will probably not get better as a result of doing exercise.

It’s best to choose exercises like swimming or biking, to keep from forcefully jarring the joint and putting extra pressure on the unprotected portion of bone below the tear. If the cartilage and the bone below it have become unstable or dislodged, exercise will make things worse, meaning surgery will probably be recommended.

Some of the muscles that support the knee attach at the hip. Like other muscles that are closer to the center or “core” of the body, these muscles give stability to joints. The muscles help put your joints in the right position, and they steady the joints while you squat, walk, or jump. Core muscles form a stable platform, letting you move your leg and foot with precision. If these muscles are weak, your knee will lose some of its control, keeping it from working at its best. 

Loss of strength after knee replacement is a common problem. This tends to happen because of aging, arthritis, and the operation itself. Ask your doctor to recommend a physical therapist who can help measure your muscle strength and plan out an exercise program just for you.

The therapist can also use a form of electrical stimulation to help build your muscles back up. By using an electric current, more of the individual fibers in the muscles contract, and with more force. This is a painless and effective method to build strength in addition to using weights.

The most common cause of pain and muscle weakness in older adults is arthritis. The surface of the joint gets worn away until the bones begin to rub against each other. This causes pain, swelling, and difficulty moving. If this is true for you, replacing the joint can relieve the pain and improve your ability to walk, climb stairs, get in and out of the car, and even take up golf or some other activity that interests you.

There are several different uses for electrical stimulation. In your grandfather’s case, an electric current is used to make the thigh muscles contract. By using this kind of stimulation, more muscle fibers are called into action and with more force. Repeating this type of treatment without completely tiring the muscle can help build your grandfather’s muscle strength.