Kellie K. Middleton, MD

9 Most Common Knee Injuries

Dec 09, 2021
9 Most Common Knee Injuries
A knee injury is the most common type of injury to send people to an orthopedic surgeon. While most knee injuries can be treated at home, some need surgical procedures...

A knee injury is the most common type of injury to send people to an orthopedic surgeon. While most knee injuries can be treated at home, some need surgical procedures. 

The knee is the largest joint in the human body, and it is one of the reasons it is also the most commonly injured joint. It has four different components – bones, ligaments, cartilage, and tendons, making them vulnerable to various injuries. 

In this guide, we’ll take you through the anatomy of the knee and the most common knee injuries. 

Let’s dive in!

Anatomy of the Knee

Anatomy of the Knee

The thigh bone or the femur is at the top of the knee joint, while the tibia or shinbone makes the bottom of the knee joint. The meeting point of the femur and tibia is covered using the kneecap, also called the patella. 

The knee moves like the door hinge, allowing individuals to bend or straighten their legs when walking, jumping, running, and squatting. 

There are many different types of knee injuries. The most common ones are –


Bones in and around the knee can be fractured as a result of a fall or high-impact trauma. People who have osteoporosis can also fracture their knees by tripping or just stepping the wrong way.

Kneecap fractures are the most common. Serious injuries cause immobilization where a cast may be worn. It allows the bones to heal by themselves, although sometimes it leads to surgery. 

Anterior Cruciate Ligament Injuries

The Anterior Cruciate Ligament or ACL is a knee tissue joining the upper and the lower bone and keeping your knees stable. It gets injured when you twist your leg or when the lower leg extends a little more forward. ACL accounts for approximately 40% of all sports-related injuries

The ACL injury can range from a small tear in the ligament to when the ligament is torn completely. It can also get separated from the bone itself.

The treatment for ACL injuries will depend on the extent of the knee damage. Not all of them need surgery and will depend on factors like the severity of the tear. Physical rehabilitation is highly recommended for any ACL injury.

Posterior Cruciate Ligament Injuries

The Posterior Cruciate Ligament or PCL is located behind the anterior cruciate ligament inside the knee and connects the femur and the shinbone. This ligament prevents the shinbone from moving far back away and causing injury. 

A PCL knee injury can occur when trauma occurs to the knee, such as when one lands on the bent knee when playing a sport. If the damage is only to the ligament, non-surgical treatment is the most appropriate. 

However, if there is a combination of injuries like torn ligaments and a dislocated knee, surgery may be necessary.

Collateral Ligament Injuries

Injury to the collateral ligament is common among players. The collateral ligament is one of the major ligaments of the knee and can easily get torn when the legs are forced to move sideways. 

In such a case, surgery is not necessary if it’s only the ligament that is torn. However, if the knee ligament is torn along with other knee structures, surgery should help fix the problem. 

Tendon Tears

Tendon is the soft tissue that connects the muscles of the knee to the bones. These tendons can get stretched and torn for a number of different reasons, such as falls, landing awkwardly, or direct force to the knee. It is a common injury among sports players and middle-aged people. 

Most tears are partial and need physical therapy along with rest for them to heal. However, a complete tendon tear requires surgery to regain knee functionality. 

Meniscal Tears

The meniscus is a small piece of cartilage between the thigh bone and shinbone. It absorbs shocks when running or during sporting activities. They may tear due to the natural aging process, also known as a degenerative meniscus tear. 

When the meniscal tear occurs, you’ll hear a sudden pop and even feel it in the knee. After the injury, you’ll feel some pain, tightness, or even swelling over the next few days. Surgery may be necessary depending on the extent and severity of the tear.


Bursae are small sacs filled with fluid cushioning the knee joints. They allow the ligaments and tendons to slide easily over the joint. Due to repeated pressure or overuse, these sacs can inflame and swell. Now, this is referred to as bursitis. 

Most bursitis cases are not severe and can be treated with self-care. Some injuries may need aspiration treatment where a needle is used to withdraw excess fluid.

Iliotibial Band Syndrome

Iliotibial Band Syndrome is quite a common injury among long-distance runners. It occurs when the iliotibial band located outside the knee rubs against the knee joint. 

The pain usually starts off as a mere irritation, but it can lead to something serious, causing the runner to stop to allow the band to heal.



A knee dislocation is an injury that occurs when the knee bones are interrupted. It is a severe condition caused by trauma due to falls or sports injuries. 

If you do not seek medical attention immediately, dislocation can cause damage to the blood vessels and nerves. 

When Should You See an Orthopaedic Surgeon for Knee Injury?

When Should You See an Orthopaedic Surgeon for Knee Injury

The cause of knee pain after an injury may be on the surface, like a cut or scrape. However, it can also be more severe, affecting the ligaments, bones, or tendons. 

Apart from pain, knee injury symptoms are swelling, a feeling of buckling, or the inability to put weight on your knees. All these require you to get medical help as soon as possible. 

Minor knee injuries are easy to treat at home through rest and using a knee brace. In case of a blunt force or trauma to the knee, it is important to consult an orthopedic specialist immediately. 

If your knee pain is chronic and lasts for a few days, contact an orthopaedic surgeon. At Kellie Middleton, we will make a diagnosis for your knee injury and recommend the best treatment options to help you get right back on track quickly.