An avulsion fracture occurs when a tendon or ligament that is attached to the bone pulls a piece of the fractured bone off.
Avulsion fractures can happen anywhere in the body but are most common in the ankle, hip, finger, and foot. They are more common in children than adults, but often affect adults who play sports.
This article looks at the causes and symptoms of avulsion fractures. It also considers the treatment options and recovery for avulsion fractures to different parts of the body.
Avulsion fractures are caused by trauma. They usually happen when a bone is moving one way, and a tendon or ligament is suddenly pulled the opposite way.
As the bone fractures, the tendon or ligament that attaches to part of the bone pulls this bone fragment away from the rest of the bone.
Certain groups are more likely to be affected by an avulsion fracture. These include:
- Children: Growth spurts can sometimes contribute to avulsion fractures. The tendons or ligaments around the parts of the children’s bones that are growing may pull so hard that the bones fracture. Children who play sports are most at risk of experiencing an avulsion fracture.
- Athletes: Many sports involve a high impact, lots of twisting, and quick changes in direction. If a person experiences an injury or impact when they are making these sorts of movements, an avulsion fracture could occur.
- Dancers: Dancers are at risk of avulsion fractures that affect the feet, as they tend to put a lot of pressure on their feet and make frequent sudden movements.
The symptoms of an avulsion fracture include:
- intense and sudden pain where the trauma occurred
- trouble moving the bone or joint
- pain when trying to move
Sometimes avulsion fractures can be misdiagnosed as muscle strain, so getting the correct diagnosis is important. A doctor can diagnose an avulsion fracture by examining the injury and carrying out an X-ray.
As research in the Journal of the American Academy of Orthopaedic Surgery notes, misdiagnosis can lead to people receiving the wrong treatment, which may lead to them doing improper exercise.
Misdiagnosis can cause:
- nerve irritation
- chronic pain
- problems walking
If a fragment of bone has been pulled more than a few centimeters away from where it usually sits, then surgery may be needed. Most of the time, however, avulsion fractures do not require surgery.
Avulsion fractures are typically treated by:
- resting the affected area
- applying ice packs
- doing exercises to strengthen muscles, improve movement, and help the bone heal
These steps help the affected bone return to its normal position naturally.
Avulsion fractures in different parts of the body require specific treatments. These include:
Hip or pelvis
When a person experiences an avulsion fracture to their hip or pelvis, it can limit their movement. One of the best ways to treat this injury is to rest.
A 2015 study showed a combination of rest and anti-inflammatory drugs allow avulsion fractures to the pelvis to heal effectively.
The following treatments may also help:
- keeping weight off the hip or pelvis by using crutches
- applying ice packs to the hip on a daily basis for the first few days of the injury
- doing exercises to stretch and strengthen the hip or pelvis, as recommended by a doctor
Following these treatments and getting plenty of rest usually allows the bone to return to its original position naturally. If it stays detached, then surgery to insert pins or screws to reattach it may be needed.
Fifth metatarsal in the foot
The fifth metatarsal in the foot, which is the bone at the base of the little toe, can be vulnerable to avulsion fractures. Dancers often experience this type of injury.
According to research published in the Journal of the American Academy of Orthopaedic Surgery, treatment for an avulsion fracture of a fifth metatarsal involves wearing a hard-soled shoe.
A person should wear the hard-soled shoe until the pain goes away, which indicates the bone fragment has reattached.
An avulsion fracture to the finger is commonly called a “jersey finger.”
The American Family Physician recommends that people who have this type of injury should visit a hand specialist. This is because there is a risk that the affected tendon could retract and cause long-term damage.
The hand specialist will recommend the best course of treatment. This may involve using a splint to hold the injured finger straight, allowing it to heal.
Occasionally, surgery is required to insert pins to hold the bone together.
Avulsion fractures of the ankle are treated in a similar way as hip or pelvis avulsion fractures, with rest and ice. In addition, the following treatments may be needed:
- a boot or cast to keep the ankle steady
- crutches to keep the weight of the ankle
- exercises to improve strength and movement
If the bone does not heal naturally with these treatments, surgery may be needed to realign the ankle.
Avulsion fractures to the shinbone (tibia) can happen while playing sports as a result of a high-powered jump. This type of fracture can be treated with:
If this does not allow the bone to heal, then surgery may be required.
An avulsion fracture is not always serious, and rest may the best treatment. However, medical help should be sought if symptoms occur.
A person with a more severe fracture may need to wear a cast for 6 to 8 weeks to allow the bone to heal.
Fractures commonly take between 3 to 12 weeks to heal. During this time, it important to rest the affected bone and keep weight off it while it heals.
If the doctor has recommended any strengthening exercises, it is important to perform them regularly to reduce the risk of long-term damage.