Shinbone (Tibia) Fracture, Causes and Symptoms
A shinbone fracture is a type of bone fracture that frequently occurs on the shinbone (tibia), particularly the proximal part of the tibia. The tibia is the stronger and larger of a set of bones found below the knee, connecting this vital joint with the bones of the ankle. Tibia fractures cause a disruption in the stability of this bone, which typically carries more weight than any other bone in the human body.
Shinbone fractures are more common than other long bone fractures, such as to the femur, fibula and humerus. Any major injury occurring above the ankle and below the knee may result in a shinbone fracture. A tibia fracture can dramatically affect the motion and stability attributed to the knee bone, and due to the force required for this type of fracture, the injuries often also spread past the knee and shinbones. Because it typically takes a major force to break a long bone such as the shinbone, other injuries often occur with these types of fractures. Resulting lesions may lead to injury in surrounding soft tissue that helps connect, support and surround other internal structures. Injuries to the surrounding ligaments and meniscus (a fibrocartilaginous structure that divides joint cavities) may also occur as a result of the fracture.
Anatomy of the Shinbone (Tibia)
The tibia, or shinbone, is the larger of two major bones making up the lower leg, the other being the fibula. This large bone connecting the knee joint and the ankle joint is responsible for supporting the bulk of our weight as we stand, walk, run, climb, and engage in other upright activities. The tibial plateau, along the upper edge of the tibia, carries most of this weight. This area is made up of two concaved condyles, which are the most prominent areas at the end of a bone, typically found where a joint forms. These are separated by a structure known as an intercondylar eminence and the sloped areas on the back and front, which help form three divided areas in the tibia:
- Medial tibial plateau (closest to the body’s center)
- Lateral tibial plateau (farthest from the body’s center)
- Central tibial plateau (between the lateral and medial plateaus)
Types of Shinbone Fracture
There are many different types of shinbone fractures that may occur depending on how the bone breaks and the force of the injury. In many cases the fibula (the other, smaller bone between the ankle and knee) is also broken. These are some of the most common ways of categorizing different types of tibia fracture:
- Stable fracture – This is a mild fracture with slight bone displacement in which the broken ends are still in place and stay aligned as the injury heals.
- Displaced fracture – Bone is displaced so the broken ends are out of alignment, often requiring surgery.
- Transverse fracture – Characterized by horizontal fracture line that can become displaced, particularly if the fibula bone has been injured as well.
- Oblique fracture – Characterized by an angled fracture line that is often unstable or may become unstable over time, particularly in cases where the femur bone is still intact.
- Spiral fracture – Injuries involving a twisting force often result in this type of fracture, which is characterized by a spiraling line that may or may not become unstable (displaced) depending on the severity of the injury.
- Comminuted fracture – This, in which three or more separated pieces of bone have fractured, is among the most unstable types of tibia fractures.
- Open fracture – Characterized by bone penetrating the skin at the point of injury, often as a result of very serious falls and vehicle accidents, with a high risk of additional damage to ligaments, muscles and tendons. Also known as a compound fracture.
- Closed fracture – Any type of fracture in which the bone does not penetrate the skin is considered a closed fracture, although the injury might still result in damage to soft tissues beneath the skin.
Causes of Shinbone Fractures
The most common shinbone fracture causes are high-speed motorcycle and automobile collisions, including those involving passengers and drivers as well as those involving pedestrians; these are also typically causes of the most severe fractures, in which several parts of the bone are broken. Other common tibia fracture causes include falls from great heights and sports injuries. Fractures caused by skiing, snowboarding, and contact sports are among the most frequent due to the twisting force of the body and likelihood of falling or making contact with other athletes.
Symptoms of Tibia Fractures
There are many different possible shinbone fracture symptoms depending on the type and severity of the injury. The most common tibia fracture symptoms include the following:
- Bone penetrating skin or poking skin from the inside
- Deformity in the knee, shin or ankle area
- Difficulty walking
- Intense pain
- Loss of sensation in foot of injured leg
- Trouble putting weight on the injured leg
- Unstable leg
It is important to seek medical attention quickly if these symptoms have surfaced following an injury involving the lower extremities. The examining physician will need as much accurate information as possible to accurately assess the injury, including personal medical history, family history, previous injuries and any medications being taken. He or she will also look for broken skin, bruises, instability, obvious deformities, swelling or other abnormalities involving the bone between the knee and ankle to diagnose for shinbone fractures. Further tests may include X-rays to check for broken and displaced bones and determine how many pieces the bone has broken into, as well as computed topography (CT) scans in cases where the fracture may have extended to the ankle or knee.
There is a variety of treatment options available for tibia fractures, depending on the locations, type and severity of the fracture, and other factors such as the patient’s overall health and whether there is damage to surrounding soft tissue or fractures in other bones. Sometimes surgery is the best option for treating a tibia fracture. In other cases where the fracture is mild and stable, or where the patient is less active or in too poor health to undergo surgery, non-surgical options may be more appropriate.
The multidisciplinary team of orthopaedic experts at North Shore-LIJ Orthopaedic Institute's Trauma Services in New York treats shinbone fractures as well as a broad range of conditions that affect the bones within the body.