What is the role of the meniscus?

The knee joint contains the meniscus structure, comprised of both a medial and a lateral component situated between the corresponding femoral condyle and tibial plateau. The meniscus withstands many different forces such as shear, tension, and compression. It also plays a crucial role in load-bearing, load transmission, shock absorption, as well as lubrication and nutrition of articular cartilage.

If you want to learn more about this topic, you can watch Prof. Jonas Thorlund's lecture here:

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How do meniscal tears occur?

In young patients, sports-related (football, basketball, soccer, baseball, and skiing in particular) injuries are the most common cause of meniscal lesions, accounting for more than 1/3 of all cases. The underlying mechanism of these injuries usually involves cutting or twisting movements, hyperextension, or actions of great force.
In middle-aged or older individuals, meniscal tears occur due to long term degeneration.

Types of meniscal tears

The 6 common types of meniscal tears are:

• Incomplete tear
• Radial tear
• Horizontal tear
• Bucket handle tear
• Flap tear
• Complex tear

What are the symptoms of meniscal tears?

Some of the common symptoms of meniscal tears include:

• Pain over centre or side of the knee
• Tenderness on palpation
• Popping or locking within the knee
• Range of motion maybe limited 
• Swelling maybe present over knee

Assessment in patients with meniscal tears

In the clinic, the diagnosis is typically based on:

• Clinical history
• Symptoms
• Clinical findings:
• Inspection
• Palpation
• Clinical tests
• Imaging (MRI)

Three common clinical tests for meniscal tears include:

• McMurray's test
• Apley's test
• Thessaly’s test

Meniscal tears in older adults

Meniscal tears findings on MRI SCAN ranges from ~5 % in young ages and up to 67 % in older ages. The older the patient is and the more osteoarthritic findings, the higher the prevalence. In middle-aged and older adults, a degenerative meniscal tear with knee pain and mechanical symptoms is indicative of osteoarthritis.

If you want to learn more about this topic, you can watch Prof. Jonas Thorlund's lecture here:

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Source:
1. Eleftherios A. Makris, Pasha Hadidi and Kyriacos A. Athanasiou;The knee meniscus: structure-function, pathophysiology, current repair techniques, and prospects for regeneration; Biomaterials Volume 32, Issue 30, Pages 7411-7431
2. Lecture ‘Meniscal Tears’ by Prof. Jonas Thorlund