Table of Contents
Introduction:
Plica is a thin, fibrous connective tissue band or folds that are present in most joints. They contain numerous small blood vessels and collagen fibers. The plica tissues are present in various joints. These tissues are known to be formed as a result of failure in the fusion of knee joints in the embryonic stage and the mesenchymal (undifferentiated ) cells tend to develop into a synovial fold called plica.
What Is Plica Syndrome?
Although plica tissues are present in various joints, the knee joint is the most common site of plica injury. Plica appears to be a harmless and unimpeded remnant of the embryonic tissue. When the plica tissues are irritated, the knee joint presents itself with painful inflammation. This condition is known as plica syndrome, characterized by anterior (front) knee pain.
What Causes Plica Syndrome?
Some of the attributed causes of Plica syndrome are the following:
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Irritation of the plica occurs typically by the compression or pitching of the tissue in between the femur (thigh bone) and the patella (knee cap).
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Direct injury in which the plica tethers the patella to the femur.
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Overuse of the knee joint can create friction of the patella over the femoral head resulting in plica inflammation.
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The thin fibrous tissue that is unobstructed during normal times becomes thick during repetitive movements and confers more irritation and inflammation.
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Sometimes plica syndrome can be mistakenly thought of as chondromalacia (cartilage injury of the knee joint).
How Does Plica Syndrome Develop?
The thin tissues of plica are normal structures that do not pose any hurdle to the normal movements of the knee joint. These disappear as the fetus grows beyond 12 weeks in the uterus. But more than 50 % of people will have these remnants in their bodies.
They are present at four different locations.
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The suprapatellar plica is located above the kneecap between the knee joint and the suprapatellar bursa.
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The infrapatellar plica is there below the kneecap between the intercondylar notch and the synovium around the infrapatellar fat pad.
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The medial plica is present at the inner side of the knee between the infrapatellar fat pad and the medial aspect of the knee joint.
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The lateral plica is found on the outer side of the knee between the infrapatellar region and the lateral patellar facet. The lateral plica is present only rarely.
Individuals may have a plica in any of the positions, and common to have more than one plica.
It is to be noted that all remnants of plica tissues will not cause pain or discomfort. They could become inflamed and painful under stressful conditions resulting from irritation. The process further leads to thick fibrotic plica impingement between two bones of the knee that is stiff enough to restrict the bending of the knee.
What Are The Stages Of Plica Syndrome?
The most common plica that becomes symptomatically painful is the medial plica. The medial plica syndrome was graded into four types by Sakakibara arthroscopic classification:
Type A: The synovial is elevated.
Type B: A small shelf-like covering appears without involving the anterior (front) surface of the medial femoral condyle
Type C: The shelf-like hood gets enlarged and covers the anterior surface of the medial femoral condyle
Type D: The plica gets a fenestration, thereby showing a distinct central defect.
What Are The Symptoms Of Plica Syndrome?
Initial stages of plica syndrome remain asymptomatic. As the condition develops, patients will complain of,
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Front knee pain.
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Clicking, popping, or grinding sounds and sensations during knee joint movements.
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Fluid collection and swelling.
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Tenderness around the joint.
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Difficult to squat.
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Stiffness and locked feelings.
How To Diagnose Plica Syndrome?
Patient history and physical manifestations of Plica syndrome are examined. As the condition involves bones and joints, radiographic images are the standard to express inflammatory changes.
1. X-Rays:
Anteroposterior (front to back), lateral (lateral view), and skyline (viewed upwards from the toe) radiographic images may help in diagnosing plica syndrome.
2. Magnetic Resonance Imaging (MRI):
MRI images are only a little beneficial in the diagnosis of plica syndrome. It is helpful in viewing thick plica when there is fluid collection along with the inflammation of the synovial membrane.
3. Ultrasound:
Ultrasound presents with more sensitivity and specificity in identifying symptomatic plica abnormalities.
4. Arthroscopy:
The gold standard investigation tool for plica syndrome is arthroscopy. A tiny camera and instruments are inserted through small incisions. The real-time images are visualized on the monitor. The procedure can also be extended for treatment purposes (minor surgical excisions).
How To Manage Plica Syndrome?
The main aim of treatment in plica syndrome is to relieve the symptoms, and the treatment planning is highly based on the Sakakibara arthroscopic classification.
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Type A and type B stages of plica syndrome are usually asymptomatic and hence respond better with conservative treatment.
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Type C and type D stages are considered more advanced, with serious impingement and pain in the knee region. Conservative treatment strategies are initiated, and most of the time, followed by surgical resection.
Conservative Treatment:
Most patients with plica syndrome can restart normal activities within a few of conservative management.
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Rest and avoid vigorous activities that make the condition symptomatic or worse.
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Exercises especially stretching and strengthening routine. They help to power up the knee joint muscles.
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Steroid shots at the site (intraplical) to reduce inflammation and swelling.
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Physical therapy.
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Non-steroidal anti-inflammatory drugs (NSAIDs) to alleviate pain.
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Ice fomentation will soothe the injured tissue by reducing the temperature.
Arthroscopy:
Initially, it is recommended to try conservative treatment for at least three months in any stage of plica syndrome. Occasionally, the symptoms may persist in a few patients. This may be due to the friction between the plica tissue and femur causing cartilage damage. Arthroscopy can be a great alternative option and yields good results.
Arthroscopy is a minimally invasive procedure to remove damaged tissue or cartilage. The healing time is faster with only a few complications.
Conclusion:
Plica syndrome can be diagnosed and well managed with great treatment outcomes. Over-the-counter painkillers and regular stretches will serve the purpose in most cases. Patient compliance is important for strict adherence to exercise routines, which is the mainstay object of conservative treatment. In later stages, intraplical steroid injections are highly effective. Prompt diagnosis is essential since the symptoms are highly suggestive of other conditions like osteoarthritis or osteochondritis.
