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, and together with the foot and thigh, form 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 bodyweight is supported by the tibia. The fibula is a smaller bone located on the outside of the leg and does not support much body weight, although it does serve important functions at the knee and ankle joint and is the attachment of muscles and ligaments.
Fractures of the Tibia
Tibial shaft fractures are significant injuries that generally occur after falls, car accidents, sports injuries, and other high-energy 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 tibia crest being the prominent ridge at the front of the shin. The top of the tibia is called the tibial plateau, and the bottom of the bone is called the tibial plafond.
Inside the hollow center of the 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. As mentioned, fractures of this part of the tibia generally are high-energy injuries that only occur after significant events. There are circumstances where the bone can be abnormally weakened, and fractures can occur with less significant injuries. These are called pathologic fractures, and occur when the bone is weakened by osteoporosis, tumor, infection, or other conditions.
Signs of Tibial Shaft Fractures
Tibial shaft fractures typically occur with significant traumatic injuries. Common signs of these fractures include:
Pain over the shin
Deformity of the leg
Swelling and bruising around the shin
Inability to place weight on the leg
Tibial shaft fractures should be evaluated in an emergency room setting. While the injury may seem obvious, it is important to assess the entire extremity to not only evaluate the tibia but also for associated injuries to the extremity. People who sustain these injuries should also have a full-body assessment, as there can be other injuries that occur that may not be obvious because of the pain in the leg.
Most all tibia fractures can be fully evaluated with x-ray tests. A stress fracture of the bone may not show up on an x-ray, and these injuries may only be evident on tests such as MRI or bone scan. However, the usual way to assess is with an x-ray to start.
Treatment Options for Tibial Shaft Fractures
A tibial shaft fracture can be treated by several methods depending on the type of fracture and alignment of the bone. The most common treatments include:
Casting: A cast is appropriate for tibial shaft fractures that are not badly displaced and are well aligned. 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 monitored to ensure adequate healing of the tibia and to ensure the bones maintain their alignment.
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 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. The most common risk of surgery is knee pain, and the most concerning complication is 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 (see information on tibial plateau and tibial plafond fractures). 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. In these cases, the placement of IM rods or plates may not be possible because of soft-tissue injury. When there is significant soft-tissue injury, the external fixator may provide excellent immobilization while allowing monitoring and treatment of the surrounding soft-tissues.
Recovery following a tibial shaft fracture generally takes a minimum of 3 months, and often quite a bit longer. The restrictions on your activity will depend on the treatment option selected. People with casts, external fixators, and plates and screws are generally restricted from weight bearing for several months. One of the advantages of an intramedullary rod is the ability to place weight on the extremity at an earlier time. Even after the fracture has healed, it is not unusual for the joint mechanics to take quite a bit longer to recover. Regaining knee and ankle mobility, strength of the lower extremity and a normal gait often takes 6-9 months. In addition, people who sustain an open tibial fracture (compound fractures) generally take longer to recover.
A Word From Verywell
Tibia fractures are generally very serious injuries. The tibia is a large, strong bone that supports the entire weight of our body. Most often these injuries are the result of serious trauma. For that reason, tibia fractures may require invasive treatment to ensure the functionality of the bone returns to normal. Without proper treatment, there are possible long term complications that may limit normal function of the extremity. People who have long term problems after a tibia shaft fracture may have difficulty walking normally.