Have you ever imagined what would happen if you could not do routine tasks like walking up and down stairs, jogging, running, hiking, kneeling and other activities because of the pain you have in your knee?

Although we may not pay a lot of attention to our knees, they play a very important role. This plain hinge joint allows your legs to support your full body weight and enables you to make all kind of movements, like twisting and turning. The knee is the one of the largest joints in the human body, and it is also the most complex and vulnerable to being injured.

Anatomy of the Knee

How much do you know about the knee? Here’s a brief anatomy lesson.

The knee consists of some primary parts. First, there are the four bones: the femur or thigh bone, patella or kneecap, tibia or shinbone, and fibula or calf bone. The knee joint is formed where the thigh bone, kneecap and shinbone meet.  Ligaments make up the next part of the knee. Ligaments join the knee bones and help to provide stability to the knee. Tendons, the third part of the knee joint, connect the bones of the knee to the leg muscles so that the knee joint can move. Muscles help to stabilize, extend and flex the knee joint. Lastly, there is cartilage. There are two types of cartilage found in the knee. Articular cartilage, which is located within the knee, coats the end of the bones in the knee joint to ensure the smooth gliding surface to the bones. Between your thighbone and shinbone, there is second type of cartilage called menisci, individually called meniscus, that provides a cushion (C-shaped) and joint stabilizer between the weight-bearing bone surfaces in the knee. Although the meniscus is tough and flexible, it is relatively easy to damage. The meniscus has blood supply in the periphery (about 30 percent of the substance), and because of this, a damaged meniscus could be healed if the injury hits somewhere in the blood flow zone.

Meniscus Tear

There are some common findings in patients with knee pain, and one of them is called a meniscus tear. It can happen when someone makes a sudden movement, like twisting or turning the upper leg while the foot is planted and the knee is bent. These kinds of risky movements that put strain on the knee are mostly done by athletes engaged in sport activities like football, volleyball, baseball and skiing; therefore, athletes involved in these kinds of sport activities are at higher risk for meniscus tears.  Older individuals are also at an increased risk, irrespective of activity level. According to a study published in the New England Journal of Medicine (NEJM), the risk of incurring a meniscus tear increase with increasing age as the result of the natural course of meniscal degeneration. 

Diagnosing Meniscus Tears

Common symptoms of meniscal tears include pain, swelling, and the feeling that your knee cannot support you anymore or cannot be moved. If left untreated, these symptoms will eventually lead you to see the doctor. Your doctor will examine your knee and may perform several tests to evaluate the meniscal tear. After that, radiological imaging may be ordered to double check or confirm the result of the physical examination. Magnetic resonance imaging (MRI) provides an accurate and less invasive way to detect meniscus tears and may avoid the surgical risks of arthroscopy, another way to diagnose meniscus tears. By utilizing the energy from radio waves and a strong magnetic field to provide detailed images of both hard and soft tissue within the knee, MRI gives a good picture of the size of a meniscus tear and detects where it is located. Thanks to new techniques, MRI could enable full knee exams to be performed in 5-10 minutes.

Since fast but accurate interpretation is expected and important, radiologists may use machine learning and deep learning, subcategories of artificial intelligence (AI), to cope efficiently with image analysis. A recent study conducted by the Balgrist University Hospital concluded that the meniscus tear detection on MRI with AI can be performed in a fully automated manner and is on par with experienced musculoskeletal radiologists. An accurate diagnosis of meniscus tear is important as it could result in a successful treatment, which could prevent subsequent related injuries or complications of meniscus tears. Getting the correct diagnosis right away can also reduce healthcare costs and therefore improve the quality of your life.

Author: Nia Ammann