Kellie K. Middleton, MD

Most Common Knee Injuries

Jan 15, 2023
Most Common Knee Injuries
The knees are a small but sensitive part of the body. These vital joints connect our thighs and legs and allow us to carry out everyday functions, including walking, running, bending, and jumping...

The knees are a small but sensitive part of the body. These vital joints connect our thighs and legs and allow us to carry out everyday functions, including walking, running, bending, and jumping.

But they can also be damaged easily. In fact, a knee injury is one of the most common types of athletic injury, and one of the most likely to need surgical treatment.

There are a number of different types of knee injuries that can and do affect people in every walk of life, particularly sports players and people with labor-intensive jobs. Here are some of the most common knee injuries that occur in the US population.

Dislocated kneecap

Dislocated kneecap

A dislocated kneecap is a common injury that occurs when the patella bone (which comprises the kneecap) comes out of place, sometimes causing the connective tissues to tear in the process. It is usually caused by pivoting (suddenly changing your direction of movement) during physical activity, or by a blow to the knee. Kneecap dislocation will usually take around 6 weeks to heal.

It should not be confused with a dislocated knee, where the thigh bone (femur) and shin bone (tibia) are separated from one another. Dislocated knees are a much less common and extremely serious injury.

Cruciate and Collateral Ligament Injury

Injuries to the ligaments of the knee happen extremely frequently, particularly in the world of professional sports. There are four ligaments in the knee – the anterior, posterior, lateral collateral, and medial collateral – and all four are somewhat prone to injury, either by being stretched or torn.

  • Anterior Cruciate Ligament: This is the central ligament in the knee that connects the femur and tibia, and propels forward movement and rotation of the shin. It is the most commonly injured ligament of the four.

Anterior Cruciate Ligament

  • Posterior Cruciate Ligament: The ligament at the back of the knee, also helps to connect the femur and tibia and controls backward movement of the shin. This ligament is the least likely to be injured outside of severe heavy impact (such as a car crash).
  • Lateral Collateral Ligament: Connects the femur to the fibula (bone on the outer part of the knee), stabilizing the inner part of the knee.
  • Medial Collateral Ligament: Also links the femur and tibia from the inside of the knee, and helps to stabilize the outside of the knee.

Cruciate and collateral ligament injuries often occur during sports. Treatment and recovery times depend on a number of things, including the severity of the injury and the age and physical condition of the injured party.

Meniscus Tear

The knee contains two pieces of cartilage, shaped like the letter ‘C’, that cushion your femur and tibia. These are the meniscus, and they can be torn in a variety of ways: while rotating the knee joint or taking heavy impact to the knee joint during sport, or even simply through squatting or getting up from a chair.

Meniscus tears are very common, with an incident rate of 61 cases per 100,000 persons in the US. As people age, their menisci degenerate, making them more prone to knee injury. Meniscus tears disproportionally affect men between 40 and 60 years old.


A patellar fracture (also known as a kneebone fracture) occurs when the patella, the bone at the front of the knee joint, is broken or fractured. They are usually caused by direct impact to the knee, or when the leg is twisted under weight. Patellar fractures are fairly common, making up approximately 1% of all broken bones.

There are four different categories of patellar fracture:

  • Displaced and non-displaced
  • Closed and open
  • Patellar sleeve fracture
  • Comminuted, noncomminuted, and hairline

The type of patellar fracture is based on how the kneecap is fractured, and the severity of the fracture.

Tendon Tears

Tendons are the connective bands of tissue that bind your muscles to your bones. The knee contains tendons at the front, sides, and back of the joint, and these tendons can be stretched or torn during bursts of excessive activity. Tendon tears occur most often while playing sports, particularly when a person is exercising too much without enough rest or downtime.

The most common types of tendon tears include patellar tendonitis (jumpers knee), quadriceps tendinitis, and pes anserine bursitis.

Treatment for Knee Injury

Depending on the type of injury and its severity, these knee injuries can be treated in different ways. Treatments for knee injuries usually fall into two divisions: surgical and non-surgical.

Non-Surgical Treatment

There are a number of non-surgical treatments that can be applied to injuries both at home and in professional environments.

  • RICE: This acronym stands for Rest-Ice-Compression-Elevation, four treatments that help to lessen pain and swelling when combined.
  • OTC Medication: Medication such as NSAIDS (non-steroidal inflammatory drugs) can be purchased without prescription to provide pain relief while dealing with short-term injury.
  • Prescription Medication: For more severe injuries doctors may prescribe certain NSAIDs and analgesics to reduce inflammation and help reduce pain inside the knee.
  • Bracing: For injuries such as torn ligaments and patellar fractures, a stabilizing brace will help to keep your legs steady and allow you to walk and move more easily during the healing process.
  • Physical Therapy: In the wake of a knee injury your doctor may prescribe physical therapy to restore movement and range of motion in your leg, and to strengthen and stabilize your knees.

Surgical Treatment

Surgical treatment to repair an injured knee is not uncommon, particularly for more severe injuries. The surgical procedure required will depend on the injury in question. For example, a torn meniscus may require a partial or total meniscectomy or meniscus repair, a bone fracture may require open reduction internal fixation surgery (ORIF), a ligament injury may call for reconstruction surgery, etc.

If you’ve experienced any one of the above knee injuries, you should seek immediate medical attention. While some knee injuries can be relatively minor and may only require rest and/or physical therapy, others may need surgery. Without appropriate treatment, the injury can worsen and affect the mobility of your knee in the long term.

Are you recovering from a knee injury, or experiencing chronic or sharp pain in the knee? If so, you may need to consult an orthopedic surgeon. Here at Kellie Middleton MD we diagnose and treat knee injuries, along with other sports-related injuries in Atlanta GA. To book your first consultation you can fill out our contact form or call us at 770-509-4030.