Fractures of the Proximal Tibia
There are several types of proximal tibia fractures. These are also called tibial plateau fractures. The bone can break straight across (transverse fracture) or into many pieces (comminuted fracture).
Sometimes these fractures extend into the knee joint and separate the surface of the bone into a few (or many) parts. These types of fractures are called intra-articular fractures.
The top surface of the tibia (the tibial plateau) is made of cancellous bone, which has a “honeycombed” appearance and is softer than the thicker bone lower in the tibia. Fractures that involve the tibial plateau occur when a force drives the lower end of the thighbone (femur) into the soft bone of the tibial plateau, similar to a die punch. The impact often causes the cancellous bone to compress and remain sunken, as if it were a piece of styrofoam that has been stepped on.
This damage to the surface of the bone may result in improper limb alignment, and over time may contribute to arthritis, instability, and loss of motion.
Proximal tibia fractures can be closed — meaning the skin is intact — or open. An open fracture is when a bone breaks in such a way that bone fragments stick out through the skin or a wound penetrates down to the broken bone. Open fractures often involve much more damage to the surrounding muscles, tendons, and ligaments. They have a higher risk for problems like infection, and take a longer time to heal.
A fracture of the upper tibia can occur from stress (minor breaks from unusual excessive activity) or from already compromised bone (as in cancer or infection). Most, however, are the result of trauma (injury).
Young people experience these fractures often as a result of a high-energy injury, such as a fall from considerable height, sports-related trauma, and motor vehicle accidents.
Older persons with poorer quality bone often require only low-energy injury (fall from a standing position) to create these fractures.
- Pain that is worse when weight is placed on the affected leg
- Swelling around the knee and limited bending of the joint
- Deformity — The knee may look “out of place”
- Pale, cool foot — A pale appearance or cool feeling to the foot may suggest that the blood supply is in some way impaired.
- Numbness around the foot — Numbness, or “pins and needles,” around the foot raises concern about nerve injury or excessive swelling within the leg.
- If you have these symptoms after an injury, go to the nearest hospital emergency room for an evaluation.
Medical History and Physical Examination
Your doctor will ask for details about how the injury happened. He or she will also talk to you about your symptoms and any other medical problems you may have, such as diabetes.
Your doctor will examine the soft tissue surrounding the knee joint. He or she will check for bruising, swelling, and open wounds, and will assess the nerve and blood supply to your injured leg and foot.
- X-rays. The most common way to evaluate a fracture is with x-rays, which provide clear images of bone. X-rays can show whether a bone is intact or broken. They can also show the type of fracture and where it is located within the tibia.
- Computed tomography (CT) scan. A CT scan shows more detail about your fracture. It can provide your doctor with valuable information about the severity of the fracture and help your doctor decide if and how to fix the break.
- Magnetic resonance imaging (MRI) scan. An MRI scan provides clear images of soft tissues, such as tendons and ligaments. Although it is not a routine test for tibia fractures, your doctor may order an MRI scan to help determine whether there are additional injuries to the soft tissues surrounding your knee. In addition, if you have all the signs of a tibial plateau fracture, but x-rays are negative, your doctor may order an MRI scan. When bone is injured there is often reaction in the bone marrow which can be detected on MRI and means that a fracture has occurred.
Other tests. Your doctor may order other tests that do not involve the broken leg to make sure no other body parts are injured (head, chest, belly, pelvis, spine, arms, and other leg). Sometimes, other studies are done to check the blood supply to your leg.
A proximal tibia fracture can be treated nonsurgically or surgically. There are benefits and risks associated with both forms of treatment.
Whether to have surgery is a combined decision made by the patient, the family, and the doctor. The preferred treatment is accordingly based on the type of injury and the general needs of the patient.
When planning treatment, your doctor will consider several things, including your expectations, lifestyle, and medical condition.
In an active individual, restoring the joint through surgery is often appropriate because this will maximize the joint’s stability and motion, and minimize the risk of arthritis.
In other individuals, however, surgery may be of limited benefit. Medical concerns or pre-existing limb problems might make it unlikely that the individual will benefit from surgery. In such cases, surgical treatment may only expose these individuals to its risks (anesthesia and infection, for example).
- Open fractures. If the skin is broken and there is an open wound, the underlying fracture may be exposed to bacteria that might cause infection. Early surgical treatment will cleanse the fracture surfaces and soft tissues to lessen the risk of infection. Soon after an accident, the injured skin and soft tissues may be further harmed by surgery. In this event, a temporary external fixator may be applied to support the limb until the soft tissues recover and surgery can safely be performed.
- External fixation. If the soft tissues (skin and muscle) around your fracture are badly damaged, or if it will take time before you can tolerate a longer surgery because of health reasons, your doctor may apply a temporary external fixator. In this type of operation, metal pins or screws are placed into the middle of the femur (thighbone) and tibia (shinbone). The pins and screws are attached to a bar outside the skin. This device holds the bones in the proper position until you are ready for surgery.
- Compartment syndrome. In a small number of injuries, soft-tissue swelling in the calf may be so severe that it threatens blood supply to the muscles and nerves in the leg and foot. This is called compartment syndrome and may require emergency surgery. During the procedure, called a fasciotomy, vertical incisions are made to release the skin and muscle coverings. These incisions are often left open and then stitched closed days or weeks later as the soft tissues recover and swelling resolves. In some cases, a skin graft is required to help cover the incision and promote healing.
Nonsurgical treatment may include casting and bracing, in addition to restrictions on motion and weight bearing. Your doctor will most likely schedule additional x-rays during your recovery to monitor whether the bones are healing well while in the cast. Knee motion and weight-bearing activities begin as the injury and method of treatment allow.
There are a few different methods that a surgeon may use to obtain alignment of the broken bone fragments and keep them in place while they heal.
Internal fixation. During this type of procedure, the bone fragments are first repositioned (reduced) into their normal position. They are held together with special devices, such as an intramedullary rod or plates and screws.
In cases in which the upper one fourth of the tibia is broken, but the joint is not injured, a rod or plate may be used to stabilize the fracture. A rod is placed in the hollow medullary cavity in the center of the bone. A plate is placed on the outside surface of the bone.
Plates and screws are commonly used for fractures that enter the joint. If the fracture enters the joint and pushes the bone down, lifting the bone fragments may be required to restore joint function.
Lifting these fragments, however, creates a hole in the cancellous bone of the region. This hole must be filled with material to keep the bone from collapsing. This material can be a bone graft from the patient or from a bone bank. Synthetic or naturally occurring products which stimulate bone healing can also be used.
Fractures that extend into the knee joint frequently require plate fixation. The plate is applied to the surface of the bone.
Fractures that are sunken must be elevated back up to restore the joint. This reduces the risk of arthritis and instability.
In some cases, the condition of the soft tissue is so poor that the use of a plate or rod might threaten it further. An external fixator (described under Emergency Care above) may be considered as final treatment. The external fixator is removed when the injury has healed.