What is Plica Syndrome?
Plica syndrome is an irritation 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, typically the result of repetitive friction to the tissue. As a result, this tissue will become thick and painful. Repetitive friction is due to abnormal forces at the knee, most likely in the kneecap and surrounding musculature, or may be caused by muscular weaknesses or structural abnormalities at the hip or foot, which place increased tension on the knee. Plica syndrome can also be caused or made worse by increased activities. In some cases, a direct hit to the knee can cause the syndrome to develop.
Plica syndrome may result from a combination of several different variables, including:
- Altered mobility of the kneecap
- Quadricep or hip muscle tightness
- Muscular imbalances in the quadriceps, hamstrings, or hip musculature
- Improper technique with repetitive activities
- Change in an exercise routine or sport activity
- Abnormal hip or knee structure
- Abnormal hip or knee mechanics
How Does it Feel?
With plica syndrome, you may experience pain and tenderness to touch in the front of the knee, and on the inside of the kneecap. You may also feel a “catching” or “snapping” sensation when bending your knee. Symptoms to watch for include:
- Tenderness to touch
- A “catching” or “snapping” sensation when bending the knee
- Dull knee pain at rest, which increases with activities
- Tightness in the knee
How Is It Diagnosed?
Your physical therapist will review your medical history and complete a thorough examination of your knee. The goals of the initial examination are to assess the degree of the injury and determine the cause and contributing factors to your injury. Your physical therapist will assess the mobility and strength of your knee. Most often your physical therapist will be able to feel a thickened piece of irritated tissue on your knee.
It is also common for your physical therapist to perform a movement assessment, which may include watching you walk, step onto a stair, squat, or balance on 1 leg. The motion and strength of other joints, including your hip and foot, may also be assessed.
Your physical therapist may also ask questions about your daily activities, exercise regimens, and footwear to identify other contributing factors.
Imaging techniques, such as x-ray or MRI, are often not initially obtained. In the case of persistent pain, your physician may decide to obtain an MRI to help identify the source of your pain.
Whether your pain was caused by a single injury or repetitive irritation, your initial examination as well as treatment will be similar. Initially the primary goals are to calm down the inflamed tissue, followed by addressing any underlying issues that may cause 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. To do so, your therapist will select treatment strategies in any or all of the following areas:
Pain: Many pain-relief strategies may be implemented, such as applying ice to the area or using therapies like iontophoresis (a medicated patch placed on the skin that is electrically charged and used to decrease pain and inflammation), or therapeutic ultrasound.
Range of motion: Your knee, hip, or foot may be moving improperly, causing increased strain at the front of the knee. Self-stretching and manual therapy techniques (massage and movement) applied to the lower body to help restore and normalize motion in the knee, hip, and foot can decrease this tension.
Manual therapy: Your therapist may apply hands-on treatments to move your muscles and joints in order to improve their motion and strength, most likely in your knee and hip. These techniques often address areas that are difficult to treat on your own.
Muscular strength: Muscular weaknesses or imbalances can result in abnormal forces in the front of the knee. Based on your specific condition, your physical therapist will design a safe, individualized, progressive, resistance program for you, likely including your core (midsection) and lower extremity. You may begin by performing strengthening exercises in a lying position (eg, lifting your leg up while lying in different positions). You then may advance to exercises in a standing position (eg, standing squats). 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 transition back into more demanding activities. To minimize the tension on the knee and your risk of repeated injury, it is important to teach your body safe, controlled movements. Based on your goals and movement assessment, your physical therapist will create a series of activities that will help you learn how to use and move your body correctly to safely perform the tasks required to achieve your goals.
Patient education: Your therapist will work with you to identify and change any external factors causing your pain, such as exercise selection, the amount of exercise you do, or your footwear. The therapist will assess you and recommend improvements, and develop a personal exercise program to help ensure a pain-free return to your desired activities.
Physical therapy promotes recovery from plica syndrome by addressing all contributing factors, such as pain and any lack of strength, flexibility, or body control. Your physical therapist may also recommend a period of relative rest, then carefully guide your progression back to normal activity levels.
When Surgery is Required
If your plica syndrome pain does not improve following several weeks of physical therapy, arthroscopic surgery may be required. Your surgeon will make 2 small incisions in the front of the knee and remove the irritated tissue. Following surgery, your initial rehabilitation will focus on decreasing pain and restoring mobility and strength. Your physical therapist will then address specific factors that caused your plica to become irritated, in order to minimize the risk of further injury. As you progress, your physical therapist will help you systematically reintroduce activities, including stair climbing, squatting, and desired recreational activities.
Can this Injury or Condition be Prevented?
Maintaining appropriate lower-extremity mobility and muscular strength, and paying particular attention to your exercise routine—especially changes in an exercise activity and the volume of exercises performed—are the best methods for preventing plica syndrome. Some patients with abnormalities in knee structure, however, may be more susceptible to developing plica syndrome.
Your physical therapist will help guide you through a process that will progressively reintegrate more demanding activities into your routine without overstraining your knee. Keep in mind that returning to activities too quickly often leads to persistent pain, and the condition becomes more difficult to fix.
Real Life Experiences
Sara is a 15-year-old high school sophomore and soccer athlete. Three weeks ago, she began experiencing knee pain during her team’s preseason training runs. She was able to complete the preseason running and weight-lifting activities, but her pain persisted. Her team is now 2 weeks into the regular season; Sara continues to experience knee pain, which limits her ability to perform well with the team. Outside of soccer, Sara experiences pain when walking and climbing stairs.
Sara and her parents are concerned about her persistent knee pain, and she worries about her ability to continue to play soccer this season. They consult her physical therapist.
Sara’s physical therapist conducts a comprehensive examination, assessing her motion, strength, balance, and movement mechanics. He gently touches the front, sides, and back of Sara’s knee to identify the exact location of her pain. Based on these findings, he diagnoses plica syndrome.
Sara, her family, and her physical therapist work together to establish short- and long-term goals and identify immediate treatment priorities, including icing and mobility exercises to decrease her pain, as well as gentle strengthening exercises. Her physical therapist also identifies appropriate soccer activities to continue—and to avoid—to help Sara heal more quickly. Sara is also prescribed a home exercise program consisting of a series of activities to perform daily to help her recovery.
Together, they outline a 4-week rehabilitation program for plica syndrome. Sara visits her physical therapist 2 times each week; he assesses her progress, performs manual therapy techniques, and advances her exercise program as appropriate. He also advises her when it is appropriate to resume additional soccer activities, and establishes a day-by-day plan to help her safely progress. Sara also performs an independent daily exercise routine at home, including stretching and strengthening activities. After 4 weeks of hard work, Sara is able to complete all of her daily and soccer activities without pain. She looks forward to competing with the team next season at the top of her form!