What to Know About Fibula Fractures

A fibula fracture occurs when there is a partial or complete break of the fibula bone. The fibula is the smaller of two bones of the lower leg, situated between the knee and ankle, that helps keep the ankle joint stable.

A fibula fracture, also known as a fibular fracture, can be caused by a severe fall, a direct blow to the outside of the leg, or a severely twisted ankle. Fibula fractures can cause swelling and pain on the outside of the leg, and other symptoms like bruising and numbness.

Fibula fractures are common in sports that require a rapid shift in direction after a jump, such as basketball. Many fibula breaks also involve the rupture of a supporting ligament and/or a fracture of the adjacent tibia bone (shin bone).

This article describes five different types of fibula fractures, including their symptoms and how they are diagnosed and treated.

What Is the Fibula?

The fibula is a long, thin bone that starts just below the knee joint on the outside of the leg and extends all the way down to the ankle joint.

The larger bone of the lower leg (called the tibia) carries most of the body weight. The fibula's primary function is to help keep the ankle joint stable.

The fibula does little to support the weight of the body. Still, it performs important functions as it is where ligaments attach to both the knee and ankle joints.

Causes of Fibula Fracture

When characterizing a fibula fracture, a specialist known as an orthopedist will want to understand the underlying cause.

Fibular fractures can be characterized in one of two ways:

• Low-energy injuries: These are caused by simple falls that athletes often experience when landing incorrectly or making a rapid shift in direction. The repetitive stress placed on the bone can make it vulnerable to breakage.
• ‌High-energy injuries: These are fractures due to high falls, high impact (such as a car accident), or blunt force trauma (such as being struck on the leg with a heavy object). Children with fibula fractures are often investigated for child abuse if it is deemed to be a high-energy injury.

Types of Fibula Fractures

The causes and treatment of fibula fractures vary by the fracture type. These are classified in one of five ways based largely on their location:

• Fibular head fractures: These occur just below the knee. They most often happen when the tibia is also fractured, usually due to a blunt-force impact on the knee.
  
• Fibular shaft fractures: These occur in the middle of the fibula bone. They often happen when the energy from a severely twisted ankle is transferred to the fibula, causing it to break in the narrowest section.
• Lateral malleolus fractures: These occur above the ankle joint. They are most often caused by tripping and falling, rolling the ankle, or being stuck in the ankle during a car accident.
• Avulsion fractures: These occur when a small piece of bone attached to a tendon or ligament gets pulled away from the main part of the bone. A severe twisting of the ankle can cause this.
• Stress fractures: These are caused by repeated stress to the fibula bone, typically in people who frequently engage in basketball, gymnastics, tennis, dance, and long-distance running.
  

Symptoms of a Fibula Fracture

Fibula fractures can occur in isolation but often happen with injuries to other bones, ligaments, or tendons around the knee and ankle.

Common symptoms of an isolated fibula fracture include:

• Pain and swelling on the outside of the leg
• Tenderness to the touch
• Inability to bear weight on the injured leg
• Bleeding and/or bruising
• Numbness or coldness in the foot
• Visible deformity

How a Fibula Fracture Is Diagnosed

To diagnose a fibular fracture, your healthcare provider will conduct a physical examination of the leg as well as the knee joint and ankle joint.

Imaging tests are central to the diagnosis, each of which can provide specific pieces of information:

• X-ray: These can identify most fibular fractures but may be less able to detect smaller stress fractures.
• Computed tomography (CT) scan: These are more commonly used if the findings from an X-ray are uncertain or to judge the severity of the injury.
• Magnetic resonance imaging (MRI): These are especially useful in diagnosing tendons or ligament tears with avulsion fractures.

Treatment Options for Fibula Fractures

How a fibula fracture is treated depends on where the fracture is located and whether other bones or ligaments are damaged.

Many isolated fibula fractures are treated with a procedure called closed reduction and immobilization. This is where the bone is manually set into the correct position and then immobilized with a cast or splint.

If possible, the orthopedist will realign your bones without surgery. If this is not possible, surgery may be needed. Options include:

• Open reduction and internal fixation (ORIF): This is when pieces of a broken bone are put into their correct position using surgery and secured together with screws, plates, sutures, or rods.
• External fixation: This is when pins are inserted through the skin and into both sides of a bone to stabilize it. The pins are then attached to the external frame outside of the body using clamps and rods.
• Percutaneous pinning: This involves the insertion of wires through the skin to hold the bone pieces in place. The wires are later removed once the fibula fracture has healed.

While isolated fibula fractures usually heal quickly, complex injuries may need further treatment.

Physical therapy is almost invariably recommended after healing to decrease pain and swelling, improve strength, increase the range of motion of the leg, and minimize scarring.

Complications

Problems with the incision or the hardware can lead to complications after surgery. Because there is very little soft tissue between the skin and the bone, wounds may not heal as easily. Wound healing may be especially troublesome for smokers and people with diabetes or arthritis.

Pain associated with implanted hardware is not uncommon. As a result, some people choose to have plates and screws removed after the fracture has healed.

As can occur with all surgeries, infection is possible. Call your healthcare provider if you develop the following signs and symptoms after an open fracture or the surgical treatment of a bone fracture:

• High fever with chills
• Increasing pain, redness, swelling, and heat at the surgical or injury site
• A pus-like or foul-smelling discharge from the wound
• Expanding redness or reddish streaks from the surgical or injury site
  

Outlook

With the appropriate treatment and physical therapy, a person with an isolated fibular fracture can expect to return to their pre-injury condition (or come close to it) within six to eight weeks. Even so, pain and swelling may continue for three to six months.

Factors that influence recovery include age, the severity of the injury, general health, smoking, and a person's commitment to physical therapy.

If treated appropriately, there are seldom any long-term limitations.

Summary

A fibula fracture involves an injury to the smaller of two bones in your lower leg. Most of the time, fibula fractures happen near the ankle joint. Repetitive stress fractures are also common. In severe cases, the tibia or ligaments are also damaged.

Symptoms include pain on the outside of the leg, swelling, and bruising. To find out whether you have a fracture, an X-ray, MRI, or CT scan will be necessary.

The treatment will depend on where and how bad the injury is. A brace or cast can keep your leg stable while the fracture heals. If the injury is severe, you may need surgery to realign the bones. Recovery from an isolated fibular fracture usually takes six to eight weeks.