What is Tibial Tubercle Avulsion Fracture

Tibial tubercle avulsion fracture is a break in the shin bone (tibia), just below the front of the knee joint (tibial tubercle). The tibial tubercle is where the tendon of the thigh muscle (quadriceps) attaches.

Adolescents have a growth plate in this area. A growth plate is a spot where bone is still growing. It is not as solid as mature bone. As a result, this type of fracture is most common in people who are 12–16 years of age.

A strong pull by the contraction of the quadriceps muscle can cause the tendon attached to it to pull a piece of bone away from the top of the tibia (avulsion fracture).

There are three basic types of tibial tubercle avulsion fractures:

• A type I fracture causes very little bone to separate from the tibia.
• A type II fracture causes most of the bone fragment to separate.
• A type III fracture causes separation and extends into the knee joint.

What are the causes?

This condition may be caused by a sudden tightening of the thigh muscle that pulls on the tibial tubercle. This can happen:

• When pushing off to jump or landing from a jump.
• When kicking a ball and having the foot contact the ground or a player.

What increases the risk?

This condition is more likely to develop in boys who are 12–16 years of age. It is a frequent injury in boys who play basketball.

What are the signs or symptoms?

Symptoms of this condition include:

• Pain.
• Swelling.
• Bruising.
• Pain when pressing on the fracture site.
• Not being able to straighten the knee.
• Not being able to put weight on the knee.
• Abnormal appearance (deformity) of the kneecap.
• Muscle spasm of the thigh.
• Feeling a lump of bone fragment in the front of the knee.

How is this diagnosed?

This condition may be diagnosed based on:

• Your child’s symptoms and history of injury.
• A physical exam of the knee. Your child’s health care provider will check for limited movement and for pain when pressing on the tibial tubercle. A bone fragment may be felt under the skin.
• X-rays. An X-ray will usually show the fracture. It may also show blood in the knee joint.

How is this treated?

Treatment depends on the type of fracture. Some type I fractures with very little displacement can be treated without surgery. This treatment may include:

• Icing the injured area.
• Taking medicines to reduce pain and swelling.
• Wearing a leg cast to prevent movement for about 6 weeks.
• Keeping weight off of the injured leg. Your child may need to use crutches or a walker.
• Physical therapy to restore knee movement and thigh muscle strength after the cast is removed.

A more severe fracture will require surgery. This includes some type I fractures and all type II and III fractures. The surgery to repair a fracture is called open reduction with internal fixation (ORIF).

Follow these instructions at home:

If your child has a cast:

• Do not allow your child to stick anything inside the cast to scratch the skin. Doing that increases your child’s risk of infection.
• Check the skin around the cast every day. Report any concerns to your child’s health care provider.
• You may put lotion on dry skin around the edges of the cast. Do not apply lotion to the skin underneath the cast.
• Do not let your child’s cast get wet if it is not waterproof.
• Keep the cast clean.

Bathing

• Do not have your child take baths, swim, or use a hot tub until his or her health care provider approves. Ask your child’s health care provider if your child can take showers. Your child may only be allowed to take sponge baths for bathing.
• If your child’s cast is not waterproof, cover it with a watertight covering when he or she takes a bath or a shower.

Managing pain, stiffness, and swelling

• If directed, apply ice to the injured area.
  • Put ice in a plastic bag.
  • Place a towel between your child’s skin and the bag.
  • Leave the ice on for 20 minutes, 2–3 times a day.
• Have your child gently move his or her toes often to avoid stiffness and to lessen swelling.
• Have your child raise (elevate) the injured area above the level of his or her heart while he or she is sitting or lying down.

Activity

• Have your child return to normal activities as told by his or her health care provider. Ask your child’s health care provider what activities are safe for your child.
• Have your child do exercises as told by his or her health care provider.
• Do not allow your child to use the injured limb to support his or her body weight until your child’s health care provider says that it is okay. Have your child use crutches as told by his or her health care provider.

General instructions

• Do not allow your child to put pressure on any part of the cast until it is fully hardened. This may take several hours.
• Give over-the-counter and prescription medicines only as told by your child’s health care provider.
• Keep all follow-up visits as told by your child’s health care provider. This is important.

How is this prevented?

To help prevent this injury, have your child:

• Lose weight if he or she is overweight.
• Warm up and stretch properly before activity.
• Allow any inflammation in the area to go away completely before returning to sports.
• Maintain physical fitness, including strength and flexibility.
• Use proper technique when playing sports.

Contact a health care provider if:

• Your child’s pain does not improve or it gets worse.
• Your child has pain, numbness, or coldness in his or her foot.
• Your child’s toes turn blue or gray.
• Your child’s cast becomes loose or damaged.