The meniscus is the substance in the knee that acts as a cushion between the thigh and leg bones. That’s the meniscus described in a nutshell.
The menisci are a complex structure that plays a vital role in the knee joint. So where exactly is the meniscus positioned?
First, there are two menisci. They are both attached to the articular surface of the tibia (the leg bone) in the knee. The medial meniscus is on the inner part of the knee, and the lateral is on the outer.
Both menisci have their distinctive shapes. The lateral meniscus is shaped more like a circle and covers a larger surface area, whereas the medial
meniscus is more C-shaped.
The menisci play an integral role in contributing to the knee joints’ stability and transmitting forces through it. The end of the femur bone that makes up
the upper part of the knee is somewhat hemispheric in shape, while the upper part of the tibia is generally a flat surface.
One can imagine a round object rolling and gliding on a flat surface isn’t all that stable. This is where the menisci come into play. They act to increase and improve contact between the femur and tibia cartilage surfaces.
Because the meniscus is more elastic than the cartilage around the tibia and femur bones, it can better absorb forces through the knee. The meniscus’ shape increases joint congruity, and the meniscus composition that improves shock absorption plays an essential role in transmitting forces.
In cases where the meniscus is lost due to injury, there is a significant increase in peak pressure between the femur and tibia bones. It, in turn, will lead to faster wear of the cartilage surfaces and, eventually, knee osteoarthritis.
Injury to the meniscus can occur as either a result of an acute injury like a fall or a sports injury, as well as a more chronic/longstanding issue.
Very often, in an acute trauma like a sports injury, the patient tends to have an Anterior Cruciate Ligament (ACL) tear with a concomitant injury
to the lateral meniscus. In contrast, chronic injuries tend to involve the medial meniscus.
So, what kind of symptoms might one experience when there is an injury to the meniscus? As stated above, meniscus injury can occur concomitantly with other injuries to structures in and around the knee, like the cartilage and ligaments.
While meniscus injury presents with only pain in most cases, one must consider that other structures may also be injured and contribute to other symptoms.
Occasionally, the meniscus might get displaced and jammed between the gliding femur and tibia bones in cases of a more severe tear. It then leads to
the knee being locked into a particular position. This condition is termed a locked knee.
As mentioned above, the menisci are an essential knee stabiliser, apart from their role in transmitting forces. They become primary stabilisers of the knee when there is an impaired function of the knee ligaments.
So, while pain is still the main symptom of meniscus injury, the symptom of knee instability should also be considered. To be more precise, conditions called ramp lesions, and root tears contribute to most cases of instability in cases of meniscus injury.
Meniscus injuries can be diagnosed from a patient’s history and examination. Magnetic Resonance Imaging (MRI) will offer an excellent indicator of the exact location and pattern of the meniscus tear and detect other concomitant injuries.
Treatment usually starts with a period of physiotherapy but often requires surgery to address the tears. Minimally invasive surgery using an arthroscope is the mainstay of treatment.
Special sutures are used to repair them. However, in more complex tears, repair may not be suitable. In such cases, the meniscus will be trimmed.
Whenever possible, it is integral that the meniscus is repaired and preserved because, as we have read above, they soften the blow to the knee. – The Health
