What Is an Avulsion Fracture?

An avulsion fracture occurs when a piece of bone that is attached to soft tissue, like a tendon or ligament, is pulled away from the main part of the bone. The fracture happens as the bone moves one way and the soft tissue to which the bone is attached moves the opposite way, taking a piece of bone with it. In fact, the word avulsion means a forcible separation.

A traumatic injury that leads to a sudden change in directional movement is what usually causes an avulsion fracture. Repetitive movements can lead to an avulsion fracture, as well.

An avulsion fracture can be painful and affect your ability to perform activities that require unique movements, such as playing sports and dancing. Fortunately, avulsion fractures are treatable and can fully heal.

Where Can Avulsion Fractures Occur?

An avulsion fracture can happen at any area where a bone is connected to soft tissue, such as the pelvis. Other areas of the body where avulsion fractures can occur are the:

Hand and Wrist

In the hand and wrist, an avulsion fracture most commonly occurs in the metacarpal bones. These are the bones that connect the wrist to the phalanges, the tubular bones forming the fingers.

An avulsion fracture known as mallet finger is also common. This fracture occurs when your extensor tendons—the tendons on the top of the hand that are used to extend or straighten your fingers—are injured.

Elbow

Avulsion fractures of the elbow occur at the triceps tendon at the back of the upper arm. This type of injury only accounts for up to 2% of tendon injuries.

Shoulder

An avulsion fracture of the shoulder can occur at the top of your upper arm (proximal humerus). The fracture can occur if the rotator cuff muscle pulled the bone the point of fracture.

Knee

Avulsion fractures can also occur at the small, rounded part of the tibia, which is the large, inner bone that starts below the knee. This avulsion fracture accounts for 0.4% to 2.7% of all growth plate injuries in children, known as physeal injuries.

Foot and Ankle

A fracture of the metatarsal (the long bones in your foot that connect your ankle to your toes) might be an avulsion fracture. The most common type of metatarsal fracture is a fifth metatarsal avulsion injury (a break to the bone connecting the ankle to the little toe).

An avulsion fracture could occur at the talus—the tough bone that makes up the part of the ankle where the shin bone and fibula (the long bone on the outside of your lower leg) meet the foot. Avulsion fractures also occur at the malleoli, the two bony areas on each side of the ankle.

Causes and Risk Factors of Avulsion Fractures

Avulsion fractures most commonly happen because of a sudden force. The force makes your bone go one way and the soft tissue the other way, with the soft tissue pulling a piece of bone with it. This type of break is more common in younger, active individuals.

People who participate in high-impact sports and activities that involve lots of twisting and changes in direction can experience avulsion fractures. If you make certain movements like a twist, leap, kick, or change in direction too quickly, you might experience an avulsion fracture.

Dancers, in particular, are at risk for avulsion fractures of the foot due to pressure and frequent sudden movement changes.

Because children are more commonly participating in sports and other activities at younger ages—when their body is still growing—it is believed that avulsion fractures might be happening more often. Fracture risk is higher during growth spurts.

Avulsion fractures also happen after repetitive actions, over time, put stress between the soft tissue and bone. The action might be repeated during a sport or job.

While rarer, you can also experience an avulsion fracture if you have a:

• History of surgery
• Genetic bone defect
• Infection
• Abnormal tissue growths, like a tumor

Avulsion Fracture Symptoms

Common symptoms of avulsion fracture include:

• Sudden, severe pain at the trauma site 
• Swelling 
• Bruising 
• Pain with movement 
• Limited movement 
• Loss of function 
• Instability of the joint 
• Muscle pain
• Popping or cracking sound at the affected bone or joint at the time of injury
• Pain in the nearby area
• Limping or pain with walking if your foot, ankle, another leg area, or hip is affected 

How Is an Avulsion Fracture Diagnosed?

The average time for the diagnosis for pelvic avulsion injuries is 20 days, according to one study. The study's authors note that the duration of treatment and time to recovery depended on diagnosis, with a delay in diagnosis prolonging that timeline. Common reasons for the diagnostic delay were not seeking immediate care, not realizing the nature of the injury, and getting the wrong diagnosis.

So that any necessary treatment is started quickly and any complications are prevented, it is important to seek medical care as soon as possible if you think you or your child has experienced an avulsion fracture.

Share all details of the injury with your healthcare provider, including how the injury occurred, if you heard something break or pop when the injury occurred, and if you’ve experienced any symptoms since. The healthcare provider will examine the affected area and see in what way your strength or range of motion may have changed. 

Your healthcare provider may order an X-ray to see the area that was injured. Sometimes, computed tomography or magnetic resonance imaging may be needed for additional insight into management and treatment decisions.

Avulsion Fracture Treatment

Most avulsion fractures can be treated conservatively without surgical intervention. In most cases, an avulsion fracture can be treated similarly to other fractures.  

In general, treatment for an avulsion fracture includes: 

• Anti-inflammatory drugs to bring down swelling 
• Activity restriction and rest
• Restrictions to how much weight you can put on the injury
• Ice application to the affected joint 
• Immobilization using a splint or cast 
• Physical therapy, which usually starts after the pain subsides

Surgery might be considered for severe avulsion fractures where the joint has become unstable. Surgery might also be done if there is a growth plate positioning concern or if there is a need to stabilize and align the growth plate.

How Long Does an Avulsion Fracture Take to Heal?

Most people can recover fully from an avulsion fracture within a few weeks or months. Healing time depends on how severe the injury is and how significant the displacement is.

Early diagnosis is critical to obtaining the best outcome and reducing healing time. If there is a delay in diagnosis and treatment, the injury can worsen, and the joint's stability might be compromised. If left untreated, an avulsion fracture may not heal or may heal incorrectly. Not receiving treatment can also cause pain and disability. 

How to Prevent Avulsion Fractures

People who play sports are at the highest risk for avulsion fractures. These fractures frequently affect adolescents who play sports while their bones are still developing. Your child might be more susceptible to an avulsion fracture if they practice too long or too hard or use the wrong techniques. 

To prevent an avulsion fracture, do not push yourself when playing a sport or participating in dance or gymnastics. If possible, avoid sudden and rapid movements, including twists and turns. 

Warming up and stretching before physical activity might also help you avoid an avulsion injury. Warm up and stretch for at least five minutes before participating in physical activity or a sport.

If you recognize that you chronically overuse a certain joint/bone area with a repetitive motion and experience pain and weakness at that site, talk with a healthcare provider about what you can do to change up your motion or protect your body. Pain and weakness can be symptoms of microtrauma, a risk factor for avulsion fracture.

You should also avoid trying to fully participate in whatever activity it was that caused your fracture before your body has fully healed. Reinjury is common.

When to See a Healthcare Provider

If you or a child experience an injury to a bone or joint, head to a local emergency room or urgent care. An avulsion injury can be severe and need care. 

After getting treated in the emergency room and going home, you should reach out to your doctor for the following:

• Numbness and tingling in the area of your injury
• The inability to move the fingers or toes below a cast or splint 
• New or worsening problems moving the affected joint
• Additional questions regarding care

A Quick Review

An avulsion fracture is an injury to a bone attached to soft tissue, such as a tendon or ligament. The tendon or ligament will pull away, taking a piece of bone with it. The most common sites for these fractures are the hips, elbows, and ankle, though any bone area close to a ligament or tendons could be affected. 

Symptoms of an avulsion fracture include sudden, severe pain at the injury site; swelling; bruising; and limited movement. An avulsion fracture is diagnosed with a physical exam and imaging. Treatment is similar to other fractures and includes rest, ice, anti-inflammatory drugs, splints or casts, and physical therapy. Surgery is considered in severe cases. 

It might be possible to prevent an avulsion fracture. Do not push yourself while playing a sport or during physical activity. Warming up and stretching before activity could also help prevent an injury. If you think you have experienced an avulsion fracture, seek medical attention to receive a diagnosis and treatment as soon as possible so that your injury can heal correctly.