An avulsion fracture happens when a tendon or ligament pulls a small fragment of bone from the main bone. These fractures usually occur near joints, such as in the fingers, hips, feet, and ankles.

Avulsion fractures are particularly common in children, but they can also happen in adults who dance or play sports. These are usually acute injuries, meaning that the break happens after a sudden force or motion.

The fracture occurs when a ligament or tendon is placed under stress. The ligament or tendon is torn off of a larger bone, carrying a small piece of bone with it.

A person may have swelling, pain, and a limited range of motion.

The treatment depends somewhat on the location of the fracture, but it usually involves resting, applying ice packs, and using a brace or splint. Once the area has healed, a doctor may recommend physical therapy to boost strength and mobility in the joint.

Below, learn about treatments for different types of avulsion fracture, as well as the causes and the likely timeline of recovery.

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An avulsion fracture happens when a tendon or ligament pulls off a small fragment of a fractured bone. Treatment usually involves:

If the bone fragment has moved more than 15 millimeters (mm), surgery may be necessary. However, most avulsion fractures do not require surgery.

Surgery may also be necessary if the fragment of bone is large, and the fracture has led to instability within the joint.

Hip

A hip or pelvic avulsion fracture can be painful, and the best approach to treatment depends on the severity. Most hip avulsion fractures occur in the growth plates of children. A growth plate is made of cartilage, which is weaker than bone.

Conservative treatment involves resting, and in some cases, using crutches to put less weight on the affected area.

Ice and some over-the-counter pain relief medication may also help. A small 2015 study recommends a combination of rest and NSAIDs for pelvic avulsion fractures. The participants also did exercises to improve strength and the range of motion in the area.

If a fracture is more serious, involving a bone fragment moving more than 15 mm, a doctor may recommend surgery. Screws, wires, or plates can help repair the bone.

Foot

Avulsion fractures in the feet and toes are relatively common. The fifth metatarsal in the foot, which is the bone at the base of the little toe, is particularly vulnerable to fractures if a person twists an ankle.

Treatment usually involves wearing a cast, brace, or walking boot to immobilize the foot. A person should only put as much weight on their foot as is comfortable and use crutches if necessary.

However, severe fractures in this area require surgery.

Finger

Sometimes called mallet finger or “baseball finger,” an avulsion fracture in the finger can happen when a fingertip is overextended.

It may not be possible for the person to straighten the tip of their finger without help. The middle, index, and ring fingers are most vulnerable to this type of fracture.

To restore function and prevent stiffness and deformity, a person should receive medical care within 1 week of the fracture.

In children, cartilage involved in bone growth may fracture in this area. Doctors must provide adequate treatment to prevent stunted growth.

Usually, treatment involves wearing a splint for at least 8 weeks. However, if the fragment is large or the joint is misaligned, surgery may be necessary.

Ankle

Treating an ankle avulsion fracture involves rest and cold therapy. A doctor may recommend crutches to minimize pressure and a cast or walking boot to stabilize the ankle. They may also suggest exercises to increase strength and mobility.

If the ankle does not heal naturally, surgery to align it may be necessary.

Usually, an avulsion fracture takes at least a few weeks to heal. However, they can take a few months to heal completely.

Until recovery is complete, avoid strenuous physical activity and putting pressure or weight on the affected joint, unless a doctor or physical therapist has recommended weight-bearing exercises.

Can it get worse?

An avulsion fracture can worsen if a person does not follow their treatment guidelines. If someone, for example, overuses the affected joint, removes their splint early, or does not do their physical therapy exercises, their condition can worsen.

A person should also check in with their doctor throughout the healing process.

Avulsion fractures are usually acute injuries, which means they are caused by a sudden event.

They happen when a bone is moving one way, and a tendon or ligament is suddenly pulled in another direction. Typically, the tendon or ligament attached to part of a bone pulls a fragment of bone away with it.

Avulsion fractures are more likely to affect certain groups, including:

  • Children: Growth spurts can sometimes contribute to avulsion fractures. The tendons or ligaments around the growth plates may pull hard enough to cause a bone fracture. Children who play sports have the highest risk of these fractures.
  • Dancers: Dancers tend to put a lot of pressure on their feet and ankles. Sudden movements and changes in direction increase their risk of avulsion fractures.
  • Other athletes: High-impact sports that involve lots of twisting and quick directional changes, such as basketball, can cause avulsion fractures.

The symptoms and signs of an avulsion fracture include:

  • intense, sudden pain
  • a popping sound
  • swelling
  • bruising
  • trouble moving the bone or joint
  • pain when trying to move it

A doctor can diagnose an avulsion fracture by examining the injury and ordering an X-ray.

Sometimes doctors misdiagnose avulsion fractures as muscle strain. As 2017 research reports, misdiagnosis can lead to improper treatment, which may involve doing exercises that are harmful.

Misdiagnosis can cause:

  • nerve irritation
  • chronic pain
  • problems walking

Anyone who suspects that they may have an avulsion fracture should receive prompt medical attention.

Avulsion fractures can occur in various locations. The cause is often sudden, twisting movements. If the fracture is minor, using ice packs, NSAIDs, splints or braces, and resting may be enough to treat it. But more severe fractures may require surgery.

A doctor can assess the extent of the injury and recommend the best course of treatment. Physical therapy can help restore strength and mobility in the injured joint.