Tibia and Fibula Shaft Fractures
I’m Ed Smith, a Sacramento Auto Accident Lawyer. Fractures of the tibia and fibula involve the two long bones of the lower leg. These represent the most common long bone fractures. There are about 26 tibia/fibular fractures per 100,000 people. Most of these injuries occur in males aged 15-19 years. There can also be fractures in 90-99 year old females at a rate of 49 out of 100,000 people in this age group. The average age of a tibial fracture is 37 years of age. There is a relatively high rate of nonunion in these types of fractures.
The tibia is the bone that carries the bulk of a person’s weight. The fibula carries only about 6-17 percent of the total weight bearing capacity of the lower leg. The fibula’s function is more for muscle insertion than it is for weight bearing. The common peroneal nerve runs alongside the neck of the fibula and so it is commonly injured when the fibula is injured.
The main mechanism of injury in a tibia/fibula shaft fracture is a high energy bending injury, such as is seen in a motor vehicle accident. This results commonly in comminuted, transverse and displaced fractures with a great deal of soft tissue injuries. Compartment syndrome and open fractures can happen and must be looked out for. Low energy bending injuries can occur with oblique or transverse fractures or butterfly fragments. These can also be comminuted and can result in open fractures or compartment syndrome. In fibular shaft fractures, direct trauma to the lateral leg is usually the cause. These are often seen as spiral fractures with rotational injuries.
Indirect fractures of the tibia and fibula can occur with falls when the foot twists. The fall doesn’t have to be from a great height in order to cause a fracture. There is usually little injury to the soft tissue.
Stress fractures can happen to these bones, especially the fibula. This can happen with military recruits who must stand and march all day long. Ballet dancers can get stress fractures as well. MRI testing may have to be done to show the presence of these injuries.
Evaluation of Tibia and Fibula Shaft Fractures
Evaluation of the nerves and blood vessels is vital to evaluating these injuries. The dorsalis pedis artery and the posterior tibial artery pulses must be established, especially if the fracture is open. Soft tissue injury must be expected and evaluated. The lower leg must be evaluated for compartment injury. There are four compartments to be concerned about in these types of fractures. If the tibial shaft is fractured, then there is a high incidence of knee ligamentous injuries. About five percent of all tibial fractures are broken in two places.
X-rays of the entire lower leg must be taken in both the front and side views. The ankle and knee must be included in those x-rays because of a high incidence of secondary injuries to these areas. Post reduction films must be taken of these same areas to see if everything is aligned. The doctor must look for comminution of the fracture, commonly seen in high impact fractures.
If there is a great deal of displacement, it means that a part of the bone may have lost its blood supply. If there is a defect, it means that part of the bone has been lost. The fracture may be transverse but there may be fracture lines that go up to the knee joint or down to the ankle joint. Air in the x-ray could mean that there is an open fracture; alternatively, it could mean that there is gas gangrene in the leg. CT scanning and MRI scanning are not usually necessary. Bone scanning with radioactive dye or MRI scan might help diagnose a stress fracture before it can be seen on x-ray.
Classification of Tibia and Fibula Fractures
These fractures are usually classified using descriptive terms such as:
- Open or closed
- Proximal third, middle third and distal third of the bone
- The presence of butterfly fragments or comminution
- Transverse, oblique or spiral
- Angulation or shortening
- Displacement degree
- Rotational component
- Other injuries along with the fractured bones
There ae two named classification systems. The first is the Gustilo and Anderson Classification, which classifies open fractures and degree of soft tissue injury. The second is the Tscherne Classification system, which classifies the amount of soft tissue injury associated with closed fractures of the tibia and fibula.
Treatment of Tibia and Fibular Fractures
These can be treated with or without surgery. If treated without surgery, the leg fractures are reduced and a long leg cast is applied with progressive weight bearing. This is best for low impact fractures that have minimal comminution and minimal displacement. Full weight bearing can be done by weeks 2-4. A fracture brace can be applied if the fracture is healing well after 3-6 weeks post-injury. Union rates for these types of fractures are as high as 97 percent but delayed weight bearing is associated with failure of the bone fragments to unite.
The fracture is considered acceptable if it is less than 5 degrees sideways angulated, less than 10 degrees anterior or posterior angulation, less than 1 cm shortened with more than 50 percent of the cortical contact made. The average time to union of these fractures is about 16 weeks but it is highly variable, depending on the type of fracture. If it takes longer than 20 weeks, it is called delayed union. Nonunion happens if 9 months go by and the fracture hasn’t healed.
If the problem is a tibial stress fracture, the treatment is to stay off the leg that is fractured, possibly using a short leg cast with partial weight bearing. If just the tibial shaft is fractured, it is treated with a short period of immobilization with weight bearing as tolerated.
Surgery depends on the location and characteristics of the fracture. Intramedullary nailing helps because it spares the blood supply to the tibia. Locked or unlocked nails may be used and the nail can be used after reaming out the inside of the bone or without reaming out the bone. Non-reamed out nails have the disadvantage of being weaker with a higher chance of hardware failure.
External fixation can be used in open fractures complicated by compartment syndrome. Union rates using this procedure is higher than 90 percent with an average time to union of about 3-4 months. Pins can become infected about 10-15 percent of the time.
Plates and screws can be used, especially if the fracture extends up into the metaphysis or epiphysis. The success rate is as high as 97 percent although there can be infection, malunion, or nonunion in cases of high impact fractures.
Complications of Tibia and Fibula Shaft Fractures
Complications include malunion, nonunion, infection (with open fractures), soft tissue loss, knee stiffness, hardware breakage, reflex sympathetic dystrophy, compartment syndrome, neurovascular injury and fat embolism.
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