The 4 Most Common Knee Injuries

March 31, 2021

The 4 Most Common Knee Injuries

Athletes speak of horror stories about career-endingknee injuries and sometimes you can’t help but wonder why that is so. 

The knee joint might be mighty with its ability to hold up your upper body weight, but it’s not perfect. Because of its range of motion, the knee is vulnerable to a handful of injuries. In this article we’ve rounded up 4 of the most common knee injuries: what they are, how to spot them, and what you can do to treat them. 

Patellar Fracture

Your patella, commonly known as your kneecap, is the triangular-shaped bone in front of your knee joint. 

Because it is your knee’s first line of defense, it can get easily fractured after a bad fall or high impact scenarios like in contact sports. 

Types of Patellar Fractures:

There are different ways that your patella can be fractured.


Stable fracture

A stable fracture is a non-displaced fracture where the broken bone fragments are relatively in contact with each other or if they’re separated, only by a minimal distance. As a stable fracture heals, the patella remains intact until it has fully recovered.


Displaced fracture

A displaced fracture is when the broken ends of the bone do not line up correctly. They are like two puzzle pieces whose ends don’t meet. In a displaced fracture, the patella’s surface may also be disrupted. This fracture often requires  surgery to put the pieces of the bones back together. 

Comminuted fracture

Not all fractures are made equal and depending on the impact, you can end up with a comminuted fracture. A comminuted fracture is when the patella shatters into three or more pieces. Depending on the intensity of the impact, a comminuted fracture can either be stable or displaced.


Open fracture

An open fracture is when the bone breaks and sticks out through the skin - yes, just like in the medical dramas. On the other hand, it can also be when a wound penetrates deep enough that it reaches down to the bone. 

An open fracture is a double whammy because you have to take care of the broken bone fragments as well as the surrounding soft tissues and skin. 

This is why open fractures take the longest to heal. They are the most serious among the fractures since there is a higher risk for infection for both the skin wound and the bone since the skin has been cut open and exposed.

Symptoms of a Fracture:

  • Swelling or bruising
  • Knee pain
  • Inability to extend the knee
  • Inability to walk

How to heal a patellar fracture

Depending on the severity of the injury, the treatment for the fracture can either be surgical or nonsurgical.

For stable fractures, your doctor might recommend a cast or a brace to aid your knee joint as it recovers. This will keep the knee immobilized and kept in the proper position as it heals and to prevent any more damage caused by bearing weight or any type of motion. In most situations, weight bearing will not be allowed for 6-8 weeks.

For more severe patellar fractures such as an open fracture, surgical treatment will be needed in order to properly heal your patella. Bone fragments that have been displaced take longer to recover - sometimes  not at all. In cases like this, your doctor must piece the broken fragments together by way of screws, small plates, pins, wires, or tension bands. 

Once the bone fragments are displaced and they aren’t given proper attention, they have the tendency to move because the thigh muscles on top of the patella pull the pieces further away as time goes on. 

Reminder: It is important to talk to your doctor once you notice symptoms of a fracture in order to heal your knee joint properly. 


A dislocation happens when the three bones in your knees don’t align: the tibia, the patella, and the femur. Knee dislocations happen after a high impact sports or vehicular accident, or more often than not, when you twist your knee while your foot is planted on the ground.

Symptoms of a Dislocation:

  • A popping sound
  • Knee pain
  • Swelling and bruising
  • Physiological changes in the knee
  • Instability
  • Inability to extend the knee
  • Inability to walk or do strenuous activities normally

How to heal a dislocated knee

For mild cases, a dislocated kneecap will spontaneously correct itself and return to its original position. Otherwise, help from your doctor will be needed to relocate your knee and snap it back to place. To reduce the pain, the patient will need to be sedated for the procedure. 

Recovery from a dislocated knee takes an average of 6 weeks until you can return to your normal activities. 


A knee sprain occurs when one or more of the knee’s 4 ligaments is overstretched or  overexerted. 

The knee joint is made up of 4 fibrous tissues that keep the knees in place: Anterior Cruciate Ligament (ACL), Posterior Cruciate Ligament (PCL), Medial Collateral Ligament (MCL), and the Lateral Collateral Ligament (LCL).

Symptoms of a Knee Sprain:

Symptoms of a knee sprain can vary depending on which ligament is sprained. 

ACL Sprain

PCL Sprain

MCL Sprain

LCL Sprain

  • Severe knee pain
  • Severe swelling
  • Severe bruising
  • Knee instability
  • A popping sound at the moment of injury
  • Mild pain that gets worse when kneeling
  • Mild swelling
  • Mild difficulty in moving the knee
  • With or without knee instability
  • Mild to severe knee pain
  • Knee instability
  • Tenderness in the inner side of the knee
  • Mild to severe knee pain
  • Knee instability
  • Tenderness in the outer side of the knee

How to heal a knee sprain

A knee sprain is the least threatening of all the knee injuries and can easily be soothed by the PRICE  method. PRICE stands for: 

P - Protect the injured area

R - Rest from any strenuous activity

I - Ice for 20 minutes at a time

C - Compress to decrease swelling

E - Elevate to keep the blood flow away from the injury

Icing and rest are the most effective methods to help your knee joint recover from a sprain. Paired with a couple of rehabilitation exercises, you’ll be back on your feet in no time. 


Meniscal tears 

Your meniscus is the knee’s shock absorber. It is the piece of cartilage that cushions the joint and absorbs the impact that occurs during physical activities. 

Meniscal tears are very common in sports that require jumping like volleyball or contact sports like football. Aside from the impact that the meniscus receives, it can easily tear when a person abruptly changes direction while running.

Symptoms of a meniscal tear:

  • A popping sound or sensation
  • Knee pain especially when rotating the knee
  • Swelling and bruising
  • Instability
  • Inability to extend the knee

Tendon tears

The patellar tendon provides stability to the knee muscles in front of the thigh. It helps straighten the legs and keeps the knee in place.


Unlike meniscal tears, tendon tears do not happen to athletes primarily. Tendon tears can happen to just about anyone, especially middle-aged people. An accident such as a fall or a high jump can potentially tear your patellar tendon and injure you.

Symptoms of a patellar tendon tear:

  • An indentation at the bottom of your kneecap (which is where your patellar tendon is located)
  • Cramping
  • Weakness
  • Tenderness
  • Swelling and bruising
  • Instability
  • Difficulty in walking, or the sensation of the knee “giving way”
  • Patella displacement (your kneecap may move up to the thigh since it is no longer securely attached to your shin)

Ligament tears

The knee ligaments we’ve mentioned above can also tear and different symptoms manifest for the different types of ligaments:



Collateral Ligaments


Located at the front of the knee joint, the ACL connects the thigh to the shin bone and helps keep it stable. 

Located at the back of the knee joint, the PCL connects the thigh to the shin bone and helps keep it stable

Located at the sides of the knee joint (medial and lateral), the collateral ligaments keeps the knee joint from moving side to side

Cause of Tear

ACL injuries are more common among athletes and dancers. 

ACL tears can occur if the lower leg extends forward too much.

PCL tears can occur when there is trauma that occurs to the knee such as when a player lands on a bent knee or the knee receives a forceful impact from the front.

Collateral ligament tears occur when the knees are forced sideways.


  • A popping sound or sensation
  • Severe knee pain
  • Rapid Swelling
  • Instability, or the feeling of the knee “giving way”
  • Loss of range of motion
  • Mild to moderate knee pain
  • Rapid Swelling
  • Instability, or the feeling of the knee “giving way”
  • Mild to severe knee pain
  • Rapid Swelling
  • Instability, or the feeling of the knee “giving way”
  • Tenderness inside the knee
  • Loss of range of motion

How to heal a tear

Mild tears to the meniscus, patellar tendon, or the ligaments often need time, rest, and physical therapy to help facilitate healing. The PRICE method also applies to mild tears and when done correctly, your knee should recover in no time. 

However, complete tears are debilitating and would require a minimally invasive procedure like arthroscopic surgery to regain complete function. 

In an arthroscopic surgery, your surgeon will make a small incision on your knee to insert a small camera called an arthroscope inside the joint in order to properly address and repair the torn meniscus, tendon, or ligament.

Recovering from Knee Joint Injuries

Recovering from knee injuries vary depending on the severity of the situation. A knee sprain can take a few weeks while an open fracture may take months. Regardless, supporting your body as it heals is the most important thing you can do. 

Knee injuries and accidents are unpredictable, so it’s best to equip yourself with the proper knowledge and tools should the need arise. 

Resting from any strenuous activity while you allow your knee to rehabilitate is key. Conservative treatments like the PRICE (Protect, Rest, Ice, Compress, and Elevate) method, taking NSAIDs (non-steroidal inflammatory drugs) like Ibuprofen, and physical therapy are effective methods to aid your recovery. has a wide range ofice packs and clay packs specifically made for your knees. These packs provide the cold therapy that you need to help get your knee back to tip-top shape. 



With, pain relief is just a click away!

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