What Is an Avulsion Fracture?
An avulsion fracture happens when a ligament or tendon pulls away a small piece of a bone. This usually results from an accident or traumatic injury. Avulsion fractures are common in the hip, elbow, and ankle in young people who play sports. However, you can have one anywhere in your body where soft tissue attaches to bone.
Avulsion Fracture Causes
Avulsion fractures usually happen near a joint. At that point, your bones connect to each other with tough bands of tissue called ligaments and connect to muscles with other tissue bands called tendons. They're more common in joints with a lot of overlapping connection points, such as your knees, or in parts of your body with many joints close together, such as your hands. In certain spots, like around your shoulder or hip, an avulsion fracture can happen when you dislocate the joint.
Any kind of strong, sudden force that sends your bone and the attachment in opposite directions can cause an avulsion fracture. Common causes are sports injuries, falls, and car crashes. You get an avulsion fracture rather than a sprain or tear because the tendon or ligament is stronger than the bone it's pulling on.
Young people are especially at risk because they're still growing, and their bones haven't fully hardened. A growth spurt can make a child's ligaments tighter than normal. Avulsion fractures also tend to happen in older people whose bones are weakened by osteoporosis.
The kinds of motions that cause them are usually quick and explosive, such as speeding up or stopping short, taking a hit, throwing hard, or twisting with a planted foot. They can also come from repetitive heavy use of a joint.
Athletic activities where you're likely to have an avulsion fracture include:
- Track
- Tennis
- Soccer
- Hockey
- Dance
- Gymnastics
- Skiing or snowboarding
It's less common, but avulsion fractures can also result from a genetic problem, an infection, or cancer, or be a complication from surgery.
Types of Avulsion Fractures
Some of the most common types of avulsion fractures are:
Pelvic avulsion fracture. This type of fracture happens in the hips, buttocks, or upper thighs. Sudden, forceful contractions of the abdominal, hip, thigh, or hamstring muscles can cause it. That can come from motions such as jumping, sprinting, or kicking.
In older people, a fall can lead to an avulsion fracture of the hip.
Fibular avulsion fracture. Your fibula is the outer bone in your lower leg. A fibular avulsion fracture is usually caused by a sudden inward rolling of your foot. It's similar to a moderate or severe ankle sprain. A sprain, however, happens when a ligament stretches or tears.
You can also have an avulsion fracture in your foot or ankle, depending on which bones are involved.
Medial epicondyle avulsion fracture. This is a type of elbow injury that happens most often in baseball players between the ages of 9 and 14 and can be caused by hard pitching. It affects the bony part that sticks out on the inside of your elbow. It's the most common elbow injury in teenagers.
Finger avulsion fracture. Mallet finger, or baseball finger, happens when something such as a baseball hits the tip of your finger or thumb. This force causes the tendon at the back of your finger to tear and rip off part of the bone with it. With this injury, you can't fully straighten your finger.
Another type of common finger avulsion injury is called jersey finger, named so because it often happens when a player grabs another player's jersey. As the player tries to get away, the finger is straightened forcefully while it's still trying to flex. The tendon and a piece of bone get pulled off the fingertip. When you have this type of avulsion fracture, you can't fully bend your finger.
Avulsion Fracture Symptoms
With an avulsion fracture, you'll usually feel sudden, severe pain, and you may hear a popping or cracking sound. Other symptoms may be different depending on where the fracture is located. They may include:
- Swelling
- Bruising
- Bleeding
- Numbness
- Tingling
- Difficulty moving your injured limb or bearing weight
- Pain radiating up or down the affected limb
How Are Avulsion Fractures Diagnosed?
Your doctor will talk to you about your symptoms and how your injury happened. They will also do a physical exam. An exam may be enough to diagnose you with an avulsion fracture.
Your doctor may order an X-ray or a CT scan to rule out other types of injuries. Imaging can also show any complications that may need surgery, such as a bone fragment trapped in the joint, or a ligament completely torn off the bone.
Avulsion Fracture Treatment
Many avulsion fractures can be treated by resting and icing the injured area and taking anti-inflammatories for pain and swelling. You may need to immobilize the joint with a device such as a finger splint, elbow brace, or cast. If the fracture is in your pelvis, leg, or foot, you may need crutches or a walking boot for a certain period.
You'll probably also need to do exercises to restore full movement, improve your muscle strength, and help your bone heal.
Generally, nonsurgical recovery for people involved in sports happens in five steps:
- Rest, ice, and protect the injury.
- Start exercise to slowly increase the range of motion of the injured area.
- Progressive resistance is introduced to help the injury.
- Use the injured area with all of the surrounding muscles.
- Prepare for a complete return to the sport.
Most avulsion fractures will heal without surgery, but if the chunk of bone is too far away from the main bone, you may need surgery. If your child has an avulsion fracture that involves a growth plate, they may need surgery as well.
Surgery usually involves one or both of these procedures:
Open reduction. The bone fragment is repositioned so it's aligned correctly with the rest of the bone.
Internal fixation. Screws, wires, and/or plates are used to hold the bone in place while it heals.
Avulsion Fractures Prevention
You are likely to reinjure yourself if you try to return to full activity too soon. To prevent avulsion fractures, it's important to focus on warming up before sports. You should also do a preseason strengthening exercise program if your sport is seasonal.
Chronic overuse can cause inflammation and trauma to your bones and make you more likely to get avulsion fractures. Don't play through the pain. If you have pain while doing sports or another repetitive activity, rest and ice the area. You may need to use a brace to immobilize it to prevent a worse injury.
Takeaways
An avulsion fracture is when a tendon or ligament pulls away a small piece of a bone. It's a common sports injury among children and teens and is often caused by car accidents or falls. While many avulsion fractures heal with just rest, some need surgery. Quick treatment can keep an avulsion fracture from getting worse, so it's important to get checked out if you or your child has symptoms.
Avulsion Fracture FAQs
How long does an avulsion fracture take to heal?
The recovery time for an avulsion fracture can be anywhere from 3 to 12 weeks. It depends on which bone is broken, whether you had to have surgery, and things such as your age and physical condition.
How serious is an avulsion fracture?
An avulsion fracture can be very serious. If you don't get treatment right away, or if you don't let it heal completely before you go back to your normal activities, you could have long-term pain, loss of function, and other complications. Some avulsion fractures need surgery.
Can I walk on an avulsion fracture?
If you have a fracture in your pelvis, leg, or foot, walking will be painful, if not impossible, at first. You may be on crutches for 1-2 weeks. But bearing weight helps bones heal, so your doctor will probably have you start walking as soon as it's safe.