Painful fold of mucous membrane in the knee

What is a mucosal fold in the knee?

A fold of the mucous membrane in the knee is a protrusion of the mucous membrane that lines the inner surface of the knee.
This mucous membrane is known as the synovia, while the occurrence of such wrinkles is known as the plica syndrome. There are three large folds in the knee (plica suprapatellaris, plica mediopatellaris, and plica infrapatellaris). These wrinkles are physiological. They are so-called reserve folds and actually regress in the course of life. In plica syndrome, they enlarge so much for various reasons that they cause problems or become symptomatic.

causes

The mucosal folds (plicae) should ideally recede completely. However, more than half of adults still have these folds of the mucous membrane or remnants of it in the knee. Strong and repetitive movements of the knee can cause irritation and pinching of these folds of the mucous membrane.

Even with existing osteoarthritis of the knee, the folds of the mucous membrane are increasingly irritated.

You might also be interested in: Knee osteoarthritis

Pinched fold of mucous membrane in the knee

A pinched fold of the mucous membrane causes sudden pain in the affected knee. The patients also describe that they have the feeling of a blockage and restricted movement in the knee and that they can no longer and do not want to put full strain on it.

The entrapment can often be released again by loosening up exercises and shaking out the knee without great force or resistance. In most cases, however, this one-off entrapment will not be the case. If this problem occurs regularly, there is probably an enlarged fold of the mucous membrane.
In consultation and in cooperation with a doctor, a therapy plan to reduce the symptoms can be worked out here.

Concomitant symptoms

Typical symptoms are pain and swelling in the knee, which is located in the area of ​​the kneecap.
The patients describe that they perceive cracking and creaking noises in the knee during various movements - increasingly when bending.

Furthermore, the range of motion of the knee is no longer fully usable and there is often resistance to be overcome when moving (often when stretching). If the leg e.g. is shaken out, the symptoms are often reduced or gone. Those affected also describe increased difficulties after long periods of sitting.

Pain on the inside of the knee

The occurrence of pain on the inside of the knee when there is a fold of the mucous membrane indicates that the middle fold of the mucous membrane (plica mediopatellaris) is enlarged. This fold is partly behind, above and below, as well as to the side of the kneecap.

If there is pinching and friction in the middle area, those affected perceive pain on the inside of the knee. In the differential diagnosis of this pain, however, osteoarthritis and malposition-related meniscus damage should also be considered.

You might also be interested in:

• Medial meniscus lesion
• Mediopatellar plica

Cartilage damage

If the cartilage is damaged, an existing fold of the mucous membrane can cause increased pain. Because the cartilage is worn or damaged, the fold of the mucous membrane rubs over the bone. This causes uncomfortable pain when moving.

On the other hand, a chronically inflamed and enlarged fold of the mucous membrane can also cause cartilage damage. The inflammation leads to hardening and fibrosis of the folds of the mucous membrane. This rubs against the cartilage and leads to inflammation and wear and tear in the long term.

More information here: Cartilage damage

What is shelf syndrome?

The shelf syndrome is the English term for plica syndrome and describes a condition of the mucous membrane folds when they are acutely or chronically inflamed and swollen due to overuse or microtrauma. Correspondingly, this leads to pain, restricted mobility and entrapment in the knee.

You can find additional information at: Shelf Syndrome

Duration

A fold of the mucous membrane in the knee does not resolve itself in adulthood. As a rule, however, this does not cause great complaints.

However, if this is inflamed and enlarged by stress, then a rest and a renunciation of the activating activity or sport for several weeks must be considered. Regular stabilizing training can prevent the problem and prevent repetitive phases of pain.

If the symptoms are less severe, they often stop when you stop exercising or take a break. If an arthroscopic procedure has been performed, in most cases everything can be done normally again after four to six weeks.

diagnosis

The diagnosis of inflamed and enlarged mucous membrane folds can often be made by an experienced doctor by describing the symptoms by the patient. The description of the blockages, bending pain, the feeling of resistance, and cracking and creaking noises suggest a fold of the mucous membrane. The lack of an accident mechanism, but the description of a stress factor (e.g. jogging on uneven terrain) also reinforce the suspicion.

In addition, in some cases the thickened fold of the mucous membrane in the knee can be felt during a palpation examination. If the results of the examination are unclear and to rule out other causes, an ultrasound, an X-ray or an MRI can be considered.

therapy

The therapy of the mucous membrane folds can usually proceed without surgery. Since the pain is usually only caused by certain movements or exercises, it can initially be recommended to refrain from this triggering activity.

In the acute situation, it makes sense to take it easy and cool. In the long term, the knee and its muscles should be strengthened. Above all, the thigh muscles can increase stability through appropriate strengthening and thus also protect the knee joint. The knee extensor (quadriceps femoris muscle) helps to let the kneecap run centrally over the knee and to ensure stable guidance. In addition, training the inner part of the muscle (vastus medialis) can prevent the kneecap from slipping. Arthroscopy may be considered if problems persist.

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Arthroscopy

Arthroscopic ablation of a fold of the mucous membrane is a relatively straightforward procedure. A rinsing system and surgical tools are inserted into the knee through two to three openings. After finding the folds of the mucous membrane, they are removed.

This entire procedure can be performed under regional (e.g. plexus anesthesia). The procedure takes no more than 15-20 minutes. After the procedure, the leg can usually be loaded again. Depending on the range of activities, there is an incapacity for work from a few days to a month. Sport should only be fully started again after two to six weeks.

Arthroscopy is recommended if the symptoms cannot be resolved by conservative procedures. Arthroscopic surgery is also a good option for people who are very active in sports to prevent long-term wear and tear (arthrosis).

Also read: Athroscopy