What is a paralabral cyst?
A paralabral cyst is a fluid-filled swelling that forms near the labrum of a joint. It is most commonly found at the shoulder or the hip. The labrum is a ring of cartilage that helps to stabilise the joint and makes the socket deeper.
Where exactly do paralabral cysts form?
These cysts most often appear around the shoulder, specifically near the glenoid labrum. The glenoid is the socket of the shoulder blade, where the head of the upper arm bone sits. The labrum keeps the head of the upper arm bone safely in place inside the socket. When small tears or injuries occur in the labrum, joint fluid can leak out into the surrounding tissue and collect there. This is how a paralabral cyst forms, which means a cyst that sits "next to the labrum".
The hip also has a labrum, called the acetabular labrum. Similar cysts can develop there too when the labrum is damaged. Paralabral cysts in other joints are much less common.
How does a paralabral cyst develop?
The cause is usually damage or a tear in the labrum. Overuse, repeated movements, an injury, or age-related wear and tear can cause the labrum to tear. At the damaged spot, joint fluid leaks out into the surrounding tissue. This fluid collects over time and forms a small or sometimes larger cyst. The cyst itself is filled with a clear, slightly sticky fluid and is surrounded by a thin wall.
What symptoms can occur?
Many paralabral cysts go unnoticed for a long time because they do not cause any discomfort. They are often found by chance during an MRI scan carried out for a different reason. Symptoms usually only appear once the cyst reaches a certain size or begins to press on nearby structures.
Common symptoms at the shoulder include a dull ache, a feeling of instability, or a clicking sensation in the joint. Sometimes there may also be numbness, tingling, or muscle weakness in the arm if the cyst is pressing on a nerve. At the hip, pain can occur in the groin or on the outer side of the thigh, especially with certain movements.
Does a paralabral cyst need to be treated?
Whether treatment is needed depends on whether there are symptoms and how large the cyst is. Small cysts that cause no symptoms generally do not need to be treated. They can remain present for a long time without causing any problems. For larger cysts or when symptoms appear, targeted treatment may be helpful.
In some cases, rest and physiotherapy are enough to ease the discomfort. However, if the cyst is pressing on nerves or significantly limiting the movement of the joint, surgery may become necessary. In most cases, not only the cyst is removed but the underlying labrum damage is also treated. The aim is to address the root cause and prevent the cyst from coming back.
Is a paralabral cyst dangerous?
In most cases, paralabral cysts do not pose a serious risk. They are benign and usually grow slowly. They only become a concern if they press on important nerves or blood vessels and cause weakness or severe pain. Such complications are rare.
Anyone who notices symptoms such as persistent pain, numbness, or weakness should have these checked by a doctor. Targeted imaging, usually an MRI scan, helps to find the exact cause and plan the right treatment.
What does aftercare look like?
After treatment, whether non-surgical or surgical, it is important to gradually put weight on the joint again and carry out targeted exercises. Physiotherapy helps to restore movement and stability. In many cases, the joint remains free of symptoms long-term after treatment, especially when the underlying cause, the labrum damage, has also been addressed.
Overall, paralabral cysts are rarely a cause for serious concern. They usually develop in connection with small tears in the labrum and only become noticeable when they press on surrounding structures. Most cysts remain harmless and do not need any specific treatment as long as they cause no symptoms. If there is any uncertainty or ongoing pain, it is worth seeing a doctor to find the right course of action.
