Most of the weight of the body is carried by the tibia (the larger bone of the lower leg). The bone outside the leg is the fibula, which is the smaller one. The fibula is a long and thin bone runs parallel to the tibia, a larger bone that also forms the shin, and attaches the ankle and knee joint. Instead, the fibula helps stabilize and support your leg, body, ankle, and leg muscles.
However, this bone has no significant role in supporting the body weight. The fibula only carries 17 percent of the body’s weight. A fibula fracture happens when more pressure is put on the bone than it can handle.
Seek emergency medical attention if you think you might have a fracture, particularly if the fracture breaks skin and bone is visible.
The Fibula
The fibula is a slender and long bone located on the outside of the lower leg, from outside and underneath the knee and extends down to form the outside of the ankle joint. Next to the fibula bone is the tibia, which is thicker. It forms the base of the knee called the tibial plateau and extends down to form the inside of the ankle joint.
The tibia and fibula are connected by ligaments underneath the knee and at the ankle. There is also a soft tissue in between the two bones, called the interosseous membrane, which runs the length of the two bones and binds the two bones together to keep them stable. The ligaments and the interosseous membrane have a little flexibility in them, to allow the ankle joint and the two bones to move during walking and motion of the ankle. The fibula can bend slightly and it can also rotate within its ligament.
The fibula bone plays a minor role in bearing the weight of the body as we walk. The tibia bears approximately 80% of the body weight. The fibula bone bears only 15 to 20% of the body weight. Moreover, it transfers forces as the ankle hits the ground during walking. The mechanism of transferring ground reaction forces occurs due to muscles attachments on the upper part of the fibula bone underneath the knee.
Types of Fibula Fractures
Fractures and breaks refer to the same condition. Fibula fractures occur around the ankle, knee, and middle of the leg. The injury is common in athlete who is engaged in collision or contact sport such as soccer, football, basketball, rugby and Lacrosse. Downhill skier, snowboarding, and skiers have high rates of fibula bone fractures as well. In the elderly population, slipped and fall is the cause of fibula bone fracture.
There are different types of fractures, which can also affect treatment and recovery. These types include:
- Lateral Malleolus Fracture, a break around the ankle
- Fibular Head Fracture, a break near the knee
- Avulsion Fracture, a fracture in which a small part of the bone gets pulled off
- Stress Fracture, a hairline fracture due to repetitive injury
- Shaft Fracture, a break that often affects the middle of the leg due to direct impact
Except for stress fractures, these fractures often occur due to a traumatic injury or more pressure placed on the bone than it can handle. This can happen when you roll your ankle, have a direct blow to the leg, fall, or experience sports-related trauma.
Causes
Fibular fractures are usually caused by:
- Low-energy injuries: Simple, ground-level falls or sports injuries that athletes usually experience.
- High-energy injuries: Injuries caused by motor vehicle accidents, for example, or gunshot wounds.
Sometimes fibular fractures can also be the result of child abuse or overuse of the bone.
Symptoms
Fibula fractures often occur with injuries to other bones, ligaments, and tendons around the knee and ankle.
Other than pain and swelling, other signs of a fibula fracture include:
- Deformity in the lower part of the leg
- Tenderness
- Swelling near the fracture
- Bruising
- Pain that gets worse when putting pressure on the leg
- Tingling or numbness, which usually happens if there is a neurovascular injury
Diagnosis
See a doctor if you have symptoms of a fracture, especially after a traumatic injury. To diagnose a fibular fracture, your healthcare provider will examine the site of the injury, the knee joint, and the ankle joint. You’ll probably need an X-ray image, too.
Other imaging studies such as magnetic resonance imaging (MRI) or a computerized tomography (CT) scan can be helpful if the fracture doesn’t show up on an X-ray. Stress fractures, described below, are more likely to show up on an MRI or CT scan.
Ankle Injuries
Fibula fractures typically occur as part of an ankle injury. If the fibula is fractured, the ankle joint should also be checked for possible injury. The most common type of fibula fracture is an injury to the end of the fibula bone near the ankle joint. These injuries can look and feel like a badly sprained ankle.
If both the fibula and inner ankle are injured, the medial malleolus or deltoid ligament may be involved. Often, surgery is needed to make the ankle joint stable. Without surgery, the ankle joint may heal without being properly aligned. Over time, that can lead to ankle arthritis.
Fibular fractures with ankle injuries will usually require surgery.
Stress Fractures of the Fibula
A fibula stress fracture is a small fracture or hairline crack in the bone. It is not as common as a stress fracture of the tibia. Here we explain the symptoms, causes, treatment, and rehabilitation of a stress fracture of the fibula.
Symptoms of a Fibula Stress Fracture
- Symptoms consist of pain in the calf area with local tenderness at a point on the fibula.
- Pain will usually have developed gradually over time, rather than a specific point in time which the athlete can recognize as when the injury occurred.
- There will be a pain in the lower leg on weight-bearing although this is not as painful as a stress fracture of the tibia.
- The pain may ease off after a period of rest but get gradually worse with exercise.
Treatment
Treatment depends on how severe the fracture is, the type, and where the injury is. Fractures are often categorized as closed (skin is intact) or open (skin is broken).
Whether closed or open, after your doctor aligns your bones, they’ll place your leg in a cast or splint. This prevents movement so the fracture can heal. You may get crutches. A physical therapist can teach you how to walk without putting weight on the broken leg.
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Closed (Simple) Fracture Treatment
Closed fractures may or may not need surgery. A splint or cast that prevents movement is usually all that is needed unless there are other parts of the leg that are also injured.
If you do require additional treatment to realign your bones, your doctor may recommend:
- Closed Reduction: Your doctor realigns ends of a broken bone without cutting into your skin.
- Open Reduction: Your doctor does invasive surgery on bones that may have broken in more than two places.
- Nonunion: Nonunion can be surgical or noninvasive, and it’s done when the ends of a fractured bone don’t heal together. When surgery isn’t needed, your doctor will usually use electrical and magnetic stimulation devices along with bone grafting.
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Open (Compound) Fracture Treatment
Seek emergency medical attention if you have an open fracture. Follow the RICE principle while you wait for help: rest, ice, compression, and elevation. Open fractures require surgery as there may be additional injuries, such as skin loss and damage to arteries.
During surgery, your doctor may use internal or external methods for fixing your fracture. For internal fixations, your doctor will place metal implants inside the broken bone to hold the fracture together while it heals. Severe open fractures require external fixations, where the metal screws or pins project outside the skin to keep the bones in place. This is usually done until you’re ready for internal fixations.
After surgery, you will get a cast to promote healing.
Ask Your Doctor
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 exact treatment will depend on where and how bad the injury is. A brace or cast can keep your leg stable while the fracture heals. But if the injury is severe or complex, you may need surgery to realign the bones.
To learn more about bone health or to schedule an appointment with one of our Ventura Orthopedic specialists, call us at 800-698-1280.
