The meniscus
The meniscus - what is it?
The meniscus in the knee is a ‘C-shaped’ fibrocartilaginous tissue, siting between the femur and the tibia. Each knee has two menisci - medial and lateral components. Both menisci are concave on the top and flat on the bottom. Blood flow to the meniscus is from the outside in and it is known that blood flow decreases with age leading to the central region of each menisci being avascular (no blood flow) by adulthood.
Both menisci act as shock absorbers or provide cushioning within the knee during loading.Without the meniscus, the articular cartilage on the end of the tibia and femur would not be protected.
One of the most common causes for knee pain is secondary to a torn meniscus. A tear in the meniscus can occur from a traumatic event, known as an acute meniscus tear. General wear and tear can also cause meniscus tears and these are often referred to as ‘degenerative’ tears. Acute meniscus tears are common in contact sports such as football as well as non contact sports requiring sharp cutting movements, such as volleyball or tennis. Meniscus tears are often associated with other knee injuries, most commonly an ACL rupture.
Signs and symptoms for a meniscus tear include:
> knee pain
> effusion
> a popping sensation at the time of injury (if acute)
> difficulty bending or fully straightening the knee
> a tendency for the knee to lock
The meniscus - conservative management vs surgery...
The following will discuss rehabilitative options for damaged menisci.
A ‘degenerative’ or age related meniscus tear is different from an acute meniscus tear. An acute tear will typical occur following a traumatic injury and the onset of pain is related to such trauma. A degenerative tear will develop more gradually over time as the cartilage starts to wear down from day-to-day activities. Many individuals with degenerative meniscus tears will have no symptoms.
Surgical options for a torn or damaged meniscus traditionally involve an arthroscopic partial menisectomy. This involves removing the part of the meniscus that has been damaged. For acute tears, it is becoming more common to repair the torn meniscus if possible to prevent the early onset of osteoarthritis. Repairs for ‘degenerative’ meniscal tears are not commonly performed due to the length of time the meniscus has undergone damage and the poor outcomes associated.
The most recent evidence has found little to no benefit for individuals with degenerative meniscus tears undergoing surgery, compared to conservative management such as physiotherapy involving exercise based rehabilitation. In 2017, the BMJ (British Medical Journal) published information regarding surgery vs conservative management for degenerative meniscus tears, and emphasised the importance to reinforce the belief that surgery rarely has any long term benefit for such pathology.
To conclude, exercise based rehabilitation that involves strengthening and improving control of the muscles around the knee should be the first course of treatment if you have a degenerative meniscus tear that is symptomatic. For individuals following an acute meniscus tear, surgery may be advised depending on your symptoms, the size of the tear, your age and your overall goals.
For any further information regarding meniscus tears or physiotherapy generally, please get in touch.
