Proximal Tibia Fracture, Causes and Symptoms
Proximal tibia fractures are fairly common lower-leg injuries. The proximal tibia is the upper part of the shinbone, which contains a large cavity that is portioned off into the medial condyle and lateral condyle. A proximal tibia fracture can result from low-energy injuries or high-energy injuries, ranging from slips and falls to major car accidents.
Blood vessels, ligaments, muscles, nerves and skin may also be injured simultaneously, so it’s crucial that orthopaedic specialists assess any damage to soft tissue to properly treat the facture. Proximal tibia fractures must be properly identified and diagnosed in order to manage the injury and restore normal range of motion, stability and strength to the limbs. Proper, simultaneous management of such fractures and any accompanying soft tissue injuries can also reduce the likelihood of arthritis in old age.
Anatomy of the Proximal Tibia
The proximal tibia is the upper part of the shinbone, which connects to the knee joint. Since the knee bears more weight than any other joint in the body and is responsible for a wide range of motions, injuries to any of its connecting bones and ligaments can be quite serious. Muscles, ligaments and other soft tissues play an important role in the stability of the knee joint, but not quite as important as the bones of the lower limbs, particularly the bone that makes up the tibial plateau. The proximal tibia is not as thick as the tibial shaft, so it is more easily injured.
There are two distinct internal areas of the proximal tibia: the medial condyle and lateral condyle. There are also two smooth articular facets in the proximal tibia’s upper surface, which articulate with the condyles of the thigh bone at the central portion and support the meniscus of the knee joint at the peripheral portion.
- Medial facet: An oval-shaped facet that concaves slightly from back to front and side to side.
- Lateral facet: An almost circular facet that is somewhat convex from back to front, but concave from side to side.
The spine of the tibia, also known as the intercondylar eminence, is found between the articular facets. This is guarded by a tubercle on either side, and marked by depressions where the menisci and posterior cruciate ligaments connect on the front and back. There are several surfaces of the proximal tibia, including the following:
- Anterior surfaces – The continuous surface of the condyles that forms a flat, smooth area with an almost triangular shape.
- Posterior surfaces – The condyles are kept apart by shallow depressions where the knee joint’s posterior cruciate ligament attaches.
- Medial surface – A convex, prominent and rough surface where the tibial collateral ligament attaches.
- Lateral surface – A convex, prominent and rough surface with a distinct area where the iliotibial band attaches.
Types of Proximal Tibia Fracture
Proximal tibia fractures may be more or less severe depending on whether the bone is broken completely or partially and whether the fracture is open or closed:
- Open fracture – The shinbone bone is exposed or protruding through the skin.
- Closed fracture – The shinbone is fractured, but the skin is not broken.
A proximal tibia fracture, or any fracture for that matter, may be classified into the following categories based on several other factors:
- Compression fracture – The bone may appear flatter or wider due to a crushing break.
- Comminuted fracture – Three or more fragments are involved in the fracture.
- Greenstick fracture – Part of the bone is broken, but the fracture is not complete, so the other side bends to compensate.
- Oblique fracture – The bone has broken diagonally across.
- Segmental fracture – The shinbone is broken in two places, leaving a fractured bone segment floating around.
- Spiral fracture – The fracture forms a spiral shape around the bone.
- Transverse fracture – The bone has broken across in a straight line.
Causes of Proximal Tibia Fracture
There are many potential proximal tibia fracture causes, which may or may not involve injuries to the knee. When the knee joint is involved, the lower limbs may become misaligned and there may be a greater likelihood of arthritis in older age, so trauma injuries to this area can be quite serious. Causes of proximal tibia fracture range from overuse to compromised bones from cancer and infection to trauma injuries, the latter being the most common. Younger people are more likely to experience this type of fracture as a result of a high-energy injury, while older people are more likely to fracture the proximal tibia during a low-energy injury.
These are some of the most common proximal tibia fracture causes:
- Falls from great heights
- Sports-related injuries
- Motor vehicle accidents
- Falls from standing positions (in older patients)
For younger people, there are often additional concerns based on the force of the injury and whether it was a bending, direct impact or vertical impact injury. Older people are more likely to have additional medical concerns that complicate the injury.
Symptoms of Proximal Tibia Fracture
Many different proximal tibia fracture symptoms may surface following the injury, and they can sometimes be ambiguous. Proximal tibia fractures may also be accompanied by other bone and soft tissue injuries in the area of the knee joint, so it’s important to undergo a complete medical examination to ensure proper diagnosis and treatment.
These are some of the most common proximal tibia fracture symptoms:
- Cool feet – A cold sensation in the foot may be sign that there is an impairment in the blood supply caused by a bone fracture in the lower limbs.
- Deformed knees – When proximal tibia fractures occur, the knee often appears deformed, even when the rest of the leg still looks normal.
- Numb feet – This is often described as a feeling of pins and needles in the foot, which comes as a result of excess swelling and/or nerve injury.
- Pain upon standing – If you experience pain whenever you put weight on your shinbone following a knee injury, it may be a sign of fracture.
- Pale feet – A pale appearance is often accompanied by a cold sensation in the foot, suggesting blood supply impairments.
- Tense knee – If the knee feels tense and is difficult to bend, it may be a sign of fracture and internal bleeding.
The multidisciplinary team of orthopaedic experts at North Shore-LIJ Orthopaedic Institute's Trauma Services in New York treats Proximal Tibia Fractures as well as a broad range of conditions that affect the bones within the body.