The tibia is the large shin bone located between the knee and the ankle. This part of the body is called—in medical terms—the leg. Together with the foot and thigh, the leg forms the lower extremity. (The leg is actually only the segment between the knee and ankle, even though many people refer to the lower extremity as the leg.)
There are two bones of the leg, the tibia and the fibula. The tibia is the larger bone that people often refer to as the shin bone. Most of the the body weight is supported by the tibia.1 The fibula is a smaller bone located on the outside of the leg and does not support much body weight. However, it does serve important functions at the knee and ankle joint and is the attachment of muscles and ligaments.
Tibial shaft fractures can occur after falls, car accidents, and sports injuries, among other activities.
The shaft of the tibia is the central portion of the bone, not the flared ends of the bone located just below the knee or above the ankle. The medical name for the shaft of the tibia is the diaphysis of the bone. The shaft of the tibia is a hollow tube, although it does have a slightly triangular shape, with the tibial crest being the prominent ridge at the front of the shin. Fractures can also occur at the top of the shin bone (proximal tibia fractures) or at the bottom of the shin bone (distal tibia fractures).
Inside the hollow center of the shin bone is the bone marrow canal. The outer part of the bone is thick and rigid; this is called the cortex of the bone and provides the strength of the tibia. When a tibia fracture occurs, the bone is disrupted, and the stability of the leg is compromised.2 Tibia fractures are usually painful injuries and generally require urgent medical treatment.
Tibia fractures are typically obvious injuries, but sometimes more subtle, non-displaced fractures can be more difficult to identify. The usual signs of a tibia fracture include:
Severe pain in the extremity2
Deformity of the leg
Tenderness directly on the bone
Inability to place weight on the leg3
When there is a concern about a possible tibial shaft fracture, an X-ray will be obtained to determine if the bone is damaged. Most often, an X-ray test is sufficient to make the diagnosis. However, in cases such as tibial stress fractures, there may still be a question about the severity of injury, and an MRI or bone scan may be performed if a fracture is suspected and the X-rays are normal.4
Most tibia fractures can be treated either as an urgent treatment, or with stabilization followed by delayed definitive treatment. However, there are situations where a tibia fracture requires emergency treatment. One of these reasons is an open fracture where the bone of the tibia has penetrated the skin. Because of the possibility of infection when the bone penetrates the skin, these fractures are generally treated as a surgical emergency.5
A tibial shaft fracture can be treated by several methods, depending on the type of fracture and alignment of the bone. Traditionally, most tibia fractures were treated with cast application or braces. However, more recently, the trend has shifted to more invasive treatments with surgical stabilization of the broken bone. The reason surgery is becoming more common is that implants and surgical techniques have improved, making the risk of surgery much lower and the benefits of much more predictable healing of the injury.
The most common treatments for a broken tibia shaft include:
Casting: A cast is appropriate for tibial shaft fractures that are not badly displaced and are well aligned.1 Patients need to be in a cast that goes above the knee and below the ankle (a long leg cast). The advantage of casting is that these fractures tend to heal well and casting avoids the potential risks of surgery, such as infection. Patients with casts must be carefully monitored to ensure adequate healing of the tibia and to ensure the bones maintain their alignment. Frequent X-rays are typically performed to ensure the healing is progressing as anticipated
Intramedullary (IM) Rodding: Intramedullary rodding is a procedure to place a metal rod down the center of the tibia to hold the alignment of the bone. A tibial rodding is a surgical procedure that lasts about an hour and a half and is usually done under general anesthesia. Patients will have an incision over the knee joint, and small incisions below the knee and above the ankle. In addition, some fractures may require an incision near the fracture to realign the bones. IM rods are secured within the bone by screws both above and below the fracture. The metal screws and the rod can be removed if they cause problems, but can also be left in place for life. Tibial rodding provides excellent fixation and alignment of the bones.6
The most common risk of surgery is knee pain, and the most concerning complication is an infection. Infection of the rod may require removal of the rod in order to cure the infection.
Plates and Screws: Plates and screws are less commonly used, but are helpful in some fracture types, especially those closer to the knee or ankle joints (such as tibial plateau and tibial plafond fractures).2 Most surgeons choose an IM rod for tibial shaft fractures unless the fracture is too close to the joint to allow for placement of the IM rod. In these fractures close to the joint surface, a plate and screws may be the ideal method of fixation.
External Fixator: An external fixator may also be helpful in some particular fracture types. External fixators tend to be used in more severe fractures, especially open fractures with associated lacerations and soft-tissue damage.7 In these cases, the placement of IM rods or plates may not be possible because of soft-tissue injury. When there is a significant soft-tissue injury, the external fixator may provide excellent immobilization while allowing monitoring and treatment of the surrounding soft-tissues.
Recovery Following Injury
Healing time following a tibial shaft fracture can be highly dependent on the type of fracture, the severity of the injury and the treatment method chosen. In general, tibial shaft fractures will take a minimum of 3 months for healing, and it is not unusual for fractures to take 4 to 6 months for a full recovery.2 Hearing this may be stressful, but remember that depending on your unique situation you may be able to do more sooner.
The amount of weight that can be placed on the extremity is also highly variable. In some situations with stable fractures held in place with metal implants, immediate weight-bearing may be allowed. In other situations where there is more of a concern about fracture alignment or stability, weight may be restricted until healing is complete.
One particular concern with tibia fractures is called a nonunion, a condition where the bone fails to heal completely. Nonunions are not common with everybody—they are more common after more severe injuries and open fractures, or in people with medical conditions that may impair bone healing. One of the most common causes of a nonunion is tobacco use, where the use of nicotine leads to delayed healing of the fractured bone, so it's important to avoid smoking and other forms of tobacco intake. A conversation with your doctor is best to determine what the best course of action is in this situation.
Complications of Treatment
While most tibial fractures will heal without complication, there are risks of both surgical and nonsurgical treatment of these injuries. Risks associated with surgery include infection, wound healing problems, nonunion of the fracture, and malalignment of the extremity.8 Nonsurgical treatment can also lead to complications including nonunion of the fracture and malalignment.
A Word From Verywell
The shin bone, also called the tibia, is a large bone of the lower extremity. Usually, injuries to the tibia are caused by significant, high energy injuries. These types of fractures often require surgical treatment, although there are situations that can also be managed with nonsurgical treatment. Complications of treatment can occur with either surgical or nonsurgical treatment and all tibia fractures should be managed by someone who specializes in fracture care.