Plica syndrome occurs when a small fold of tissue in the knee joint (the synovial membrane) gets irritated. This membrane makes fluid that keeps the knee joint lubricated. When the tissue on the inside of the kneecap is irritated, it can cause pain and tenderness. Plica syndrome often results from overuse but can also follow a direct hit to the knee. Physical therapy is the most common treatment. It improves knee motion and strength and reduces irritation.

Physical therapists are movement experts. They improve quality of life through hands-on care, patient education, and prescribed movement. You can see a physical therapist directly for evaluation and treatment without a physician’s referral.* To find a physical therapist in your area, visit Find a PT.

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On this page

• What Is Plica Syndrome?
• How Does It Feel?
• How Is It Diagnosed?
• How Can a Physical Therapist Help?
• Can This Injury or Condition Be Prevented?
• What Kind of Physical Therapist Do I Need?

What Is Plica Syndrome?

Plica syndrome is an irritation of part of the synovial membrane in the knee. The synovial membrane encloses the knee joint and contains the fluid that keeps the joint lubricated. Plica syndrome results when the synovial lining becomes irritated. This is typically the result of repetitive friction to the tissue from abnormal forces on the kneecap and surrounding muscles. Muscle weakness or structural problems at the hip or foot can increase tension on the knee, causing friction. In some cases, plica syndrome is caused by a direct hit to the knee. As a result, the tissue will become thick and painful.

Plica syndrome may result from a combination of factors, including:

• Decreased mobility (movement) of the kneecap.
• Tightness in the quadriceps (front of the thigh) or hip muscles.
• Imbalances in the quadriceps, hamstrings (back of the thigh), or hip muscles.
• Repetitive activities done without proper technique.
• Sudden changes in exercise, activity or sport.
• Increased activities.
• Abnormal hip or knee structure.
• Abnormal hip or knee mechanics (how the joints move).
• Injury.

How Does It Feel?

People with plica syndrome may experience:

• Pain and tenderness when touching the front of the knee and on the inside of the kneecap.
• A "catching" or "snapping" sensation when bending the knee.
• Dull knee pain at rest, which increases with activity.
• Tightness in the knee.

How Is It Diagnosed?

Your physical therapist will review your medical history and examine your knee. The goal is to determine the degree of injury, its cause, and contributing factors. They will check the mobility and strength of both lower extremities. These include your foot and ankle as well as your knee and hip. Often, a physical therapist can feel a thickened piece of irritated tissue on your knee.

They may also perform a movement assessment, such as watching you walk, step onto a stair, squat, or balance on one leg.

Your physical therapist may ask questions about your daily activities, exercise regimens, and footwear. Your answers can help identify other contributing factors.

Imaging techniques, such as X-rays or MRI, may not be necessary at first. In the case of persistent pain, an X-ray may help rule out other injuries. Your physician also may order an MRI to help identify the source of your pain.

Whether your pain was caused by a single injury or repetitive irritation, your exam and treatment will be similar. The primary goal is to calm the inflamed tissue. Your physical therapist will then address any underlying issues that may be causing continued tissue irritation.

How Can a Physical Therapist Help?

You and your physical therapist will work together to develop a plan to achieve your specific goals. It may include treatment strategies in any or all of the following areas:

Pain. Your physical therapist can use different treatments to help decrease pain and inflammation. They may at first apply ice to the area. Then they may use therapies like iontophoresis (a medicated patch placed on the skin that is electrically charged). They also may tape the knee. These treatments work best when combined with a personalized exercise program designed by a physical therapist. Your physical therapist will work with you to reduce your pain as much as possible without the use of pain medication, including opioids.

Range of motion. Your knee, hip, or foot may be moving improperly. This can cause increased strain at the front of the knee. Self-stretching and manual therapy techniques (massage and movement) can be applied to the lower body. These help restore normal motion in the knee, hip, and foot and reduce tension in the knee.

Manual therapy. Your physical therapist may apply hands-on techniques (manual therapy) to gently move your muscles and joints. This can improve motion and strength. These treatments are usually applied to the knee and hip to treat plica syndrome. These techniques often address areas that are difficult to treat on your own.

Muscle strength. Muscular weaknesses or imbalances can apply abnormal forces to the front of the knee. Based on your specific condition, your physical therapist will design a safe resistance program for you. It will likely include your core (midsection) and lower extremities and concentrate on the muscles around the hip and knee. These exercises may be completed in different positions, such as lying down, sitting, or standing. Your physical therapist will choose what exercises are right for you based on your age and physical condition.

Functional training. Once your pain, strength, and motion improve, you will need to safely advance to more demanding activities. It is important to teach your body safe, controlled movements to reduce the risk of repeated injury. Your physical therapist will create a series of activities to help you learn how to move your body correctly. They will teach you how to safely perform the tasks required to achieve your goals.

Education. Your physical therapist will work with you to identify and change any external factors causing your pain. These might include your exercise selection, the amount of exercise you do, or your footwear. Your physical therapist will assess your current condition and lifestyle and recommend improvements. They will develop a personal exercise program to help ensure a pain-free return to your desired activities.

Physical therapy helps people recover from plica syndrome by addressing all contributing factors. These may include pain, lack of strength, flexibility, or body control. Your physical therapist also may recommend a period of rest. They will carefully guide your progression back to normal activity.

When Surgery Is Needed

If your plica syndrome pain does not improve after three months of physical therapy, arthroscopic surgery may be needed. Your surgeon will make small incisions in the front of the knee and remove the irritated tissue. After surgery, early physical therapy will focus on decreasing pain and restoring mobility and strength. Your physical therapist will then address specific factors that led your plica to become irritated. Their guidance will help you minimize the risk of further injury. As you improve, they will progress your program to include movements like stair climbing, squatting, and safely return to your desired activities.

Can This Injury or Condition Be Prevented?

Maintaining strength and movement in your leg, ankle, and foot and paying close attention to your exercise routine are the best ways to prevent plica syndrome. Make any exercise changes gradually and watch your weekly training volume.

These actions can lower your risk of injury.

Some patients with an abnormal knee structure may be at higher risk for developing plica syndrome.

If you have plica syndrome, your physical therapist will guide you through your recovery. Your treatment program will gradually re-introduce more demanding activities without overstraining your knee. Keep in mind that returning to activities too quickly often leads to persistent pain. This makes the condition more difficult to fix. Once you have completed your rehabilitation, your newfound strength, flexibility, and knowledge may help you prevent the syndrome from recurring.

What Kind of Physical Therapist Do I Need?

All physical therapists are prepared through education and experience to treat plica syndrome. However, you may want to consider:

• A physical therapist who is experienced in treating people with plica syndrome. Some physical therapists have a practice with an orthopedic or musculoskeletal (muscle, bone, and joint) focus.
• A physical therapist who is a board-certified clinical specialist in orthopedics or who completed a residency or fellowship in orthopedic or sports physical therapy. This physical therapist has advanced knowledge, experience, and skills that may apply to your condition.

You can search for physical therapists with specific experience or expertise using the American Physical Therapy Association’s Find a PT tool.

General tips when you're looking for a physical therapist (or any other health care provider):

• Ask family, friends, or other health care providers to recommend a physical therapist.
• Ask about the physical therapists' experience in helping people with plica syndrome or knee painwhen you contact the clinic for an appointment.
• Be prepared to describe your symptoms in as much detail as possible. Make a note of what makes your symptoms better or worse.