Meniscal cyst
A meniscal cyst is a fluid-filled sac that forms near a meniscus, often associated with a tear in the meniscus. It may remain asymptomatic or cause localized pain on the side of the knee.
The aim of treatment is to understand the origin of the symptoms and to choose an appropriate response. Surgery is not always necessary: it is discussed based on the level of discomfort, the clinical examination, and any associated injuries.
UNDERSTANDING THE MENISCAL CYST
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This fibrocartilaginous structure distributes stress between the femur and the tibia. A fissure can sometimes allow fluid to pass into the surrounding tissues.
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An opening in the meniscus can communicate with the cyst. It does not always cause symptoms on its own.
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This fluid-filled pocket is most often located near the joint line, next to the affected meniscus.
RECOGNIZING THE SYMPTOMS
The symptoms of a meniscal cyst depend on its size, location, and any associated meniscal tear. Discomfort may appear gradually or after activity that puts stress on the knee.
- Localized pain: It is often located on the inner or outer side of the knee, near the joint line. It may be more pronounced when pressure is applied or during certain movements.
- Small, perceptible mass: A protrusion near the joint can sometimes be felt or seen, especially when the knee is straight.
- Restriction of movement during bending: Bending your knee, squatting, or standing up can become uncomfortable. The discomfort varies depending on the position and the activity.
- Swelling or snagging: Swelling or a feeling of catching may be present, especially if a meniscal tear is associated.
These signs can have other causes and are not sufficient to confirm a meniscal cyst. Diagnosis is based on examination of the knee and, if necessary, appropriate imaging.
→ Learn more about meniscus injuries
HOW DOES A MENISCAL CYST FORM?
A meniscal cyst often occurs when joint fluid leaks through a tear in the meniscus and accumulates in the surrounding tissues. Several conditions can contribute to this formation.
A tear in the meniscus
A tear can create a communication between the inside of the joint and the tissues next to the meniscus. Fluid can then accumulate there.
Repeated constraints
Repetitive bending, pivoting, or squatting movements can put stress on the meniscus. They do not necessarily cause a cyst, but can contribute to revealing an existing injury.
A twisting injury
A sudden movement of the knee, especially when the foot remains planted on the ground, can cause a meniscal tear. A cyst may develop in connection with this tear.
A progressive meniscal tear
Some fissures develop gradually, without any specific trauma. The cyst may then be discovered during an evaluation for localized pain.
MAKE THE RIGHT DIAGNOSIS
Diagnosis is based on symptoms, clinical examination, and further investigations when necessary. An image of a cyst or fissure should always be interpreted in light of the actual discomfort.
01 — THE INTERROGATION
The doctor specifies where the pain is located, how it appeared, and which movements trigger it. He also looks for any sensation of a lump, a snagging, or an injury.
02 — THE CLINICAL EXAMINATION
The examination assesses knee mobility, pain upon palpation, and signs that may suggest a meniscal tear or another cause. It helps to put the symptoms into perspective.
03 — IMAGING, SO NECESSARY
An MRI can determine the presence, location, and extent of the cyst, as well as the condition of the meniscus. It is not interpreted in isolation: the result must correspond to the symptoms and the examination.
An image alone is not enough to decide on a treatment: it is the patient's discomfort that guides the care.
RELIEVING A MENISCAL CYST WITHOUT SURGERY
When the discomfort remains limited and there is no significant blockage, non-surgical management is often considered first. This aims to reduce stress on the knee and monitor the evolution of symptoms.
Treatment is tailored to the pain, activities, and any associated meniscal tear. The presence of a cyst on imaging does not automatically mean that intervention is necessary.
TEMPORARILY ADAPT ACTIVITIES
Temporarily reducing movements that clearly trigger pain, such as repetitive pivoting or deep bending, can help alleviate discomfort. The goal is to maintain tolerated activities without putting undue stress on a painful knee.
MANAGING PAIN AND SWELLING
Relative rest, the application of cold compresses protected by a cloth, and appropriate pain relief measures can contribute to comfort. The choice of medication should take into account the patient's health status and any treatments already being taken; it is best to discuss this with a healthcare professional.
RESUME THE MOVEMENT GRADUALLY
Physiotherapy may be recommended depending on the symptoms to maintain mobility and gradually resume activities. Exercises are tailored to the level of pain and should not cause stiffness or persistent worsening of the condition.
MONITOR THE DEVELOPMENT
The size of the cyst and the pain can change differently from person to person. A reassessment is recommended if the mass increases, if symptoms persist, or if the knee locks.
Conservative management is decided according to the symptoms and their evolution, and not solely on the presence of the cyst.
WHEN TO CONSIDER SURGERY?
Surgery may be considered if pain remains significant despite appropriate treatment, if the cyst interferes with activities, or if the associated meniscal tear causes mechanical symptoms. The decision depends on the overall assessment.
Surgical treatment generally aims to address the cyst and the associated meniscal tear. The choice of technique depends on the location of the lesion and the possibility of preserving the meniscus.
Persistent symptoms
Persistent discomfort that limits walking, activities, or sleep may warrant further evaluation. Surgery is considered only after other options have been explored and the cause of the symptoms confirmed.
A bothersome cyst associated with a fissure
When the cyst is painful or large and a meniscal tear is identified, arthroscopic treatment may be considered. The goal is to treat the underlying cause and the cyst, while preserving as much of the meniscal tissue as possible.
A completely locked knee
A persistent inability to straighten or bend the knee requires medical evaluation. Depending on the examination and imaging, surgical advice may be indicated, but the locking must first be confirmed and explained.
KEEP MOVING WITH KNEE OSTEOARTHRITIS
When the knee allows, movement is generally preferable to prolonged immobilization. However, it is advisable to limit movements that trigger significant pain or a catching sensation.
Walking on level ground and low-impact activities can be maintained if they remain comfortable. Resumption of deep flexion, pivoting, and sports activities should be gradual, depending on the symptoms.
Mild, temporary discomfort may prompt an adjustment of intensity. Increasing pain, significant swelling, or blockage requires stopping the activity and seeking medical advice.
The key is to maintain a tolerated level of activity while allowing the knee time to recover. The pace of resumption depends on the injury, the pain level, and each individual's goals.
Resuming activity gradually allows you to observe the knee's reaction and adjust your efforts accordingly.
A CARE APPROACH TAILORED TO EACH PATIENT
A meniscal cyst does not cause the same level of discomfort for everyone. Treatment depends in particular on the pain, mobility, activities, and the presence of an associated meniscal tear.
Dr. Benoît Coulin takes into account the clinical examination, the duration of symptoms, and imaging results when indicated. Age, occupation, and personal goals also help to define treatment priorities.
A conservative approach may be preferred when symptoms allow. If an intervention is discussed, its expected benefits, limitations, and possibilities for preserving the meniscus are addressed with the patient.
«"The decision is based on your symptoms, your examination, and your goals."»
FREQUENTLY ASKED QUESTIONS
IS YOUR KNEE STILL PAINFUL OR ANNOYING?
A clinical examination and, if necessary, appropriate imaging can help to determine the origin of the symptoms and to propose a personalized treatment plan.
