Common Knee Conditions
Anatomy of the Knee
The knee is the body's largest joint. It's the place where three bones meet: the tibia, the femur and the patella. The knee is a "hinge" joint. It allows the leg to bend in one direction only. Let's take a closer look at the main parts of the knee's anatomy.
The base of the knee is formed by the tibia. This bone, also called the "shinbone," is the large bone of the lower leg. The smaller bone of the lower leg, called the "fibula," connects to the tibia just below the knee. It is not part of the joint. Above this is the femur, which is also known as the "thighbone." This is the longest, largest and heaviest bone of the body. The patella, commonly called the "kneecap," covers and protects the front of the knee joint.
Within the knee, the surfaces of the bones are covered with a layer of articular cartilage. This tough, smooth tissue protects the bones. It allows them to glide smoothly as the knee flexes and extends.
Between the tibia and femur are two thick pads called "menisci." Each one individually is called a "meniscus." These are made of cartilage. They act as cushions for the two rounded protrusions on the end of the femur, which are called the "condyles."
The tibia and the femur are connected to each other by a pair of strong bands of tissue called "cruciate ligaments." The anterior cruciate ligament is commonly called the "ACL." The posterior cruciate ligament is commonly called the "PCL." These ligaments cross each other like an X in the center of the knee. The ACL keeps the tibia from slipping forward, and the PCL keeps it from slipping backward. These ligaments also limit the knee's rotation.
Anterior Cruciate Ligament (ACL) Injuries in Women
The anterior cruciate ligament, commonly called the ACL, is a thick, elastic band of tissue that runs from the bottom of the femur to the top of the tibia. It helps stabilize the knee joint. The ACL can become stretched or torn when the knee is twisted or hyperextended. For reasons that are not fully understood, ACL injuries are much more common in women than in men.
The anatomy of women's hips and legs may make women more prone to ACL injuries. Men's knees generally align directly under their hips. Women have wider hips than men, and this increases the angle at which women's femurs meet their tibias at the knee joints. This increased angle may place a greater amount of stress on the ACL during certain movements.
Joints and Muscles
Other differences in anatomy may also play a role. Women's joints tend to be more flexible than men's. Women's muscles tend to be weaker. The space around the ACL is narrower in women than in men. All of these anatomical differences can put women at a greater risk for ACL injury.
Movement Differences in the way men and women move their bodies may also be a factor. Men tend to begin participating in vigorous athletic sports at a very young age, while women tend to start at a later age. This can allow men more time to condition their bodies to the stresses of jumping, cutting and pivoting.
While doctors are still studying the factors that play a role in women's ACL injuries, studies have shown that female athletes can lower their risk of these injuries by strengthening the muscles of the legs and by learning proper techniques for running and jumping.
Bursitis of the Knee
This is a swelling of a fluid-filled sac called a "bursa." It's on the inner side of your knee, between the tibia and the tendons that attach to your hamstring muscle. You have similar sacs near other large joints throughout your body. They act as cushions between your bones and your soft tissues. Normally they have a small amount of fluid inside them. But sometimes they can swell. We call that "bursitis."
Knee bursitis results from constant stress or friction against your bursa. It is most often caused by overuse. It can happen if you do a lot of running. It's often a problem for active people who are out of shape, or who don't use proper training techniques. It can also be caused by arthritis.
Knee bursitis causes pain and tenderness. You feel it on the inner side of the leg below the knee joint. This pain develops slowly. It gets worse with activity. Treatment Treatment options include rest, medications and physical therapy. If these aren't helpful, you may benefit from surgery. Your healthc
Iliotibial Band Syndrome (ITBS)
Overview - Iliotibial Band Syndrome
This is a problem on the outer side of your thigh. It's an inflammation of the iliotibial band. That's a thick band of tissue that spans from your hip to your shinbone. When this band becomes in inflamed, it can hurt.
Causes - Iliotibial Band Syndrome
This syndrome is caused by overuse. As you move your leg, the iliotibial band can rub against the bones of your hip and knee. Over time, that irritates it. Iliotibial band syndrome is common in cyclists and runners. Poor training habits may raise your risk. You're also more likely to develop it if the structure of your leg causes the band to rub.
Symptoms - Iliotibial Band Syndrome
For many people, iliotibial band syndrome causes knee pain. You feel it on the outer side of your knee. But you can feel pain anywhere along the length of this band, all the way up to your hip. The pain gets worse with activity, and feels better with rest.
Treatment - Iliotibial Band Syndrome
Treatment depends on the severity of your symptoms. If the inflammation is mild, you may be able to treat it with rest, stretches and medications. If these aren't helpful, you may need to try other options. In very severe cases, the iliotibial band can be released with surgery. Your healthcare provider can create a plan that's right for you.
Lateral Collateral Ligament (LCL) Injury
Overview - Lateral Collateral Ligament (LCL) Injury
This is a stretching or tearing of a ligament on the outer side of your knee. The lateral collateral ligament, commonly called the "LCL", connects the femur to the fibula. The LCL helps stabilize your knee. This ligament, along with the medial collateral ligament, helps prevent excessive side-to-side movement of your knee joint. It helps keep the upper and lower leg aligned properly.
Causes - Lateral Collateral Ligament (LCL) Injury
You can injure your LCL when your knee is pushed sideways toward the outer side of your body. A hard blow to the inner side of your knee is a common culprit. With a mild injury, your LCL may only stretch. Some of its fibers may tear. But if your injury is severe, your LCL may rupture completely.
Symptoms - Lateral Collateral Ligament (LCL) Injury
An LCL injury causes pain and swelling of the outer side of your knee. Your knee may feel stiff. It may feel unstable and weak. It may lock or catch when you walk. Some people experience numbness or weakness in the foot after an LCL injury.
Treatment - Lateral Collateral Ligament (LCL) Injury
Many LCL injuries can be treated with rest, ice and physical therapy. You may benefit from a knee brace. If these are not helpful, you may benefit from surgery to repair the damage. Your healthcare provider can develop a care plan that is right for your needs.
Medial Collateral Ligament (MCL) Injury
Overview - Medial Collateral Ligament (MCL) Injury
This is a stretching or tearing of a ligament on the inner side of your knee. The medial collateral ligament, commonly called the "MCL", is connected to the femur and to the tibia. The MCL helps stabilize your knee. This ligament, along with the lateral collateral ligament, helps prevent excessive side-to-side movement of your knee joint. It helps keep the upper and lower leg aligned properly.
Causes - Medial Collateral Ligament (MCL) Injury
You can injure your MCL when your knee is pushed sideways toward the inner side of your body. A hard blow to the outer side of your knee is a common culprit. With a mild injury, your MCL may only stretch. Some of its fibers may tear. But if your injury is severe, your MCL may rupture completely.
Symptoms - Medial Collateral Ligament (MCL) Injury
An MCL injury causes pain and swelling of the inner side of your knee. Your knee may feel stiff. It may feel unstable and weak. It may lock or catch when you walk. Some people experience numbness or weakness in the foot after an MCL injury.
Treatment - Medial Collateral Ligament (MCL) Injury
Many MCL injuries can be treated with rest, ice and physical therapy. You may benefit from a knee brace. If these are not helpful, you may benefit from surgery to repair the damage. Your healthcare provider can develop a care plan that is right for your needs.
Overview - Mensiscus Tear
This is a common injury of the knee. Your knee joint is cushioned by two c-shaped wedges of cartilage called the "menisci." Each individual cushion is called a "meniscus." This injury is a tear of one of these cushions.
Causes - Mensiscus Tear
Meniscus tears are often caused by physical activity. Twisting or rotating your knee suddenly can cause a meniscus to tear. Kneeling, squatting and heavy lifting can as well. And as you age, your menisci gradually become thin and brittle, which can increase your risk for a tear.
Symptoms - Mensiscus Tear
Symptoms may include a popping sensation and pain in your knee. You may have trouble straightening your leg. It may swell and stiffen, and it may lock in place.
Treatment - Mensiscus Tear
Treatment options include rest, ice and medications. You may benefit from physical therapy. If these are not helpful, you may benefit from a surgical procedure to repair the damage. Your healthcare provider can create a care plan that is right for your needs
Anterior Cruciate Ligament Tear (ACL Tear)
This injury is a tearing of the ACL ligament in the knee joint. The ACL ligament is one of the bands of tissue that connects the femur to the tibia. An ACL tear can be painful. It can cause the knee to become unstable.
An ACL tear usually occurs during athletic activity. The ACL can tear during abrupt movements such as sudden stops, pivots or directional changes. The ACL can also tear when a person jumps and lands awkwardly. In some cases, ACL tears are caused by a traumatic injury such as a vehicular accident or a violent tackle.
A common symptom of an ACL tear is a popping sound or sensation in the knee at the moment of injury. The knee may be very painful, and it may swell. It may feel unstable. The person may be unable to continue physical activity.
In some cases, an ACL tear can be treated conservatively in patients who have a low activity level. Nonsurgical options may include crutches, a knee brace, and strengthening and stability exercises. For active patients, surgery and rehabilitation are commonly required.
Osteoarthritis of the Knee
Osteoarthritis, also called degenerative arthritis, is a gradual breakdown of cartilage in the joints. Cartilage is a tough, flexible connective tissue that protects the ends of bones in the joints. Osteoarthritis is common in the knees because the knees bear the weight of the body. Osteoarthritis of the knee can severely impact a person's lifestyle.
Causes and Risk Factors
Osteoarthritis commonly develops as a result of the wear and tear of aging. It also frequently results from traumatic injury to the joint. Osteoarthritis of the knee is more common in older people, in women, and in people who have occupations that place increased stress on the knees. People who have certain diseases, bone deformities or a genetic predisposition are also at a higher risk. Obesity can also raise a person's risk for osteoarthritis of the knee, because extra body weight increases stress on the knee joints.
In a healthy knee, the ends of the bones are covered by a layer of cartilage. Healthy cartilage allows the bones to glide smoothly against each other. But in a knee with osteoarthritis, this cartilage begins to deteriorate and wear away. Repetitive motion or injury may speed this deterioration. Eventually, the bones may rub directly against each other.
Bone Spur Formation
This rubbing can cause the gradual growth of bony bumps along the edge of the joint. These lumps, called bone spurs (or osteophytes), can cause joint pain.
Quadriceps Tendon Tear
Overview - Quadriceps Tendon Tear
This condition is a tear of the tendon that connects the patella to the quadriceps muscles of the thigh. The quadriceps muscle is used to straighten the leg from the bent position. A complete rupture of the quadriceps tendon is a disabling injury.
Causes - Quadriceps Tendon Tear
This type of injury is often caused by trauma. It can result from an awkward landing after a jump or a fall. It can be caused by a direct blow, or by a laceration to the front of the knee. A person whose tendons are weakened is at an elevated risk for this type of injury. Tendon weakness can be caused by chronic conditions such as diabetes, kidney disease, lupus, rheumatoid arthritis and leukemia.
Tendon weakness can also be caused by the use of corticosteroids, the use of certain antibiotics, and by long periods of immobilization.
Symptoms - Quadriceps Tendon Tear
A quadriceps tendon tear is a painful injury. It may result in swelling, bruising, tenderness and cramping. If the tendon ruptures completely, the person will often feel a popping sensation. The person will be unable to straighten the leg from a bent position. The person will have difficulty walking. The patella may slip downward, leaving an indentation at the top of the knee.
Treatment - Quadriceps Tendon Tear
Treatment options depend on the severity of the tear. A partial tear may be treated with rest, immobilization of the knee, and (after a period of healing) physical therapy. A complete rupture requires surgery to reattach the quadriceps muscles to the pate
Shin Splints (Medial Tibial Stress Syndrome)
Overview - Shin Splints
This is pain you feel in the front of one or both of your lower legs. It can be a problem for runners, dancers, gymnasts and other active people.
Causes - Shin splints is an overuse problem. It can develop when you increase your activity level or change your activity routine. Running on hard surfaces is a common culprit. Repetitive, high-impact leg activities can damage the muscles, tendons and bones of your lower legs. The connective tissue that holds muscle to bone can stretch and tear. This causes inflammation and pain. Shoes are worn out or that don't fit properly can increase your likelihood of getting shin splints.
Symptoms - Shin Splints
If you have this condition, you may feel sharp or dull pain in one or both legs. This pain gets worse with exercise and better with rest. If your shin splints are severe, your legs may hurt even when you aren't active.
Treatment - - Shin Splints
Shin splints heal on their own with proper rest. You can help your shin splints heal by avoiding high-impact activities and by icing your legs. Physical therapy and orthotics may also help. Your healthcare provider can create a plan that is right for you.
Overview - Tibial Fractures
This is a break of the shinbone. That's the larger of the two bones in the lower leg. Tibias are strong bones that support most of your body's weight.
Causes -Tibial Fractures
Fracturing a tibia requires a lot of force. You can break a tibia in a traumatic accident. Road accidents are common culprits. Falls are, too. Tibia fractures are also a problem for skiers, and for people who play contact sports. Diseases that weaken your bones can make a fracture more likely.
Types of Fractures
There are many types of fractures. You can have a small crack in the bone, or the bone can be broken into two or more parts. A break in the upper or lower part of the bone may also damage the knee or ankle joint.
Symptoms - Tibial Fractures
A tibia fracture is painful. Your leg may swell, and you may not be able to put any weight on it. If you have a bad fracture, your bone may shift. It can push against or even through through your skin. And if a broken bone presses against a nerve in your leg, it can cause a loss of feeling in your foot.
Treatment - Tibial Fractures
Treatment options depend on your fracture. Some fractures can heal in a cast, but others need surgery. Your healthcare provider can create a plan that's right for you.
Tibial Plateau Fracture
Overview - Tibial Plateau Fracture
This condition is a fracture at the top of the tibia, also called the shin bone. This fracture usually involves both bone and cartilage, so there is a high risk of developing arthritis from injury to the cartilage cells.
Causes - Tibial Plateau Fracture
A tibial plateau fracture is usually caused by sudden, direct trauma to the knee, or by force that drives the tibia up into the knee joint. Serious falls and automobile accidents are common culprits.
Symptoms - Tibial Plateau Fracture
Common symptoms include pain, swelling, bruising, and weakness or lack of mobility in the knee.
Treatment - Tibial Plateau Fracture
For fractures that have not shifted, surgery may not be needed. The most common non-surgical treatment is a short leg, non-weightbearing cast or a hinged knee brace, combined with physical therapy and rest. Fractures that have shifted require surgery.