What is a Supracondylar Femoral Fracture?
Supracondylar femoral fracture (also called a distal fracture) is when the thigh bone, or femur, is broken at the knee. The knees are the largest weight weight-bearing joint in your body. The distal femur Forms the top part of the knee joint. The lower part of the knee joint is the shin bone, or tibia. A distal fracture is a break in the femur where it forms the knee. Articular cartilage is a smooth substance called that cushions the two bones and helps them move against each other. A distal fracture may also damage the cartilage of the knee. There are 3 different types of distal femur fractures:
- Transverse fracture. The bone breaks straight across.
- Comminuted fracture. The bone breaks into many pieces.
- Intra-articular fracture. The fracture extends into the knee joint and damages the cartilage.
Fractures can also be open or closed. An open fracture is when the bone or fragments stick out through the skin, or a wound goes all the way through the skin down the bone. Open fractures may damage muscles, tendons, and ligaments, so they take longer to heal. A closed fracture is when the skin stays intact.
Most people with a distal femur fracture are not able to put any weight on the injured leg. They experience pain in the knee and sometimes the thigh. Other symptoms include:
- Misshapen knee (looks out of place)
- Shortened or crooked leg
The femur is the strongest and largest bone in your body, so it takes a large force to break it. Usually, supracondylar femoral fractures are due to blunt force from an auto or motorcycle accident, being hit by a car, or a big fall.
In older patients, supracondylar fractures are common in those with osteoporosis, or brittle bones. In the elderly, when the distal femur breaks, it can be a more serious fracture. The bone is more likely to be shattered into many pieces, and the fracture can extend into the knee joint.
Diagnosis and Tests
To find out if you have a distal femoral fracture, the doctor will examine your leg and knee. The following tests may be recommended to confirm the diagnosis and to rule out any additional injuries:
- X-rays. X-rays use low-level radiation to take pictures of your bones. X-rays can show of your bones are broken or intact.
- CT scan. A CT scan uses x-rays and a computer to create a cross-section of bone and tissue. It will show if the fracture is a simple break or if the bone is broken into many pieces.
- MRI or ultrasound. These tests are used to look at the soft tissue in the body and may be needed to check for damage to the blood vessels or other soft tissue in your leg.
Treatments & Prevention
There are nonsurgical and surgical treatments for supracondylar femoral fracture.
- Casts and braces. In general, casts and braces can hold fractured bones in place as you heal. But with supracondylar femoral fracture, the muscles in the thigh often contract and pull the bone pieces apart. Casts and braces may not work well with this type of fracture, unless it is stable and the bone pieces are well aligned.
- Skeletal traction. Skeletal traction is when the patient lies in bed with a system of pulleys, weights, and counterweights holding the leg in a specific position so the pieces of bone stay together. Pins or screws can help keep the bone in the right position as you heal.
The drawbacks to nonsurgical treatment are that casting can be uncomfortable and stop you from getting around or doing physical therapy, and exercises that can help you heal faster. It is best to get up and around after an injury to prevent stiffness and problems from extended bed rest. For these reasons, your doctor may recommend surgery instead.
Open fractures are at risk of infection, so surgery needs to be done right away. With a closed fracture, your surgery may be scheduled one to three days later to give your health care providers the chance to do tests and make a plan. Your doctor may do one of several surgeries:
- External fixation. If your muscles and skin need time to heal before surgery, or if you have other health problems, your surgeon may use an external fixator. This is a stabilizing frame on the outside of your leg connected to pins and screws that hold the bones in place until you are ready for surgery. When you have surgery, the doctor will remove the external fixator and put an internal fixator on the bone under the muscles.
- Internal fixation. There are two common procedures your surgeon may use to permanently set the bone. An intramedullary nail is a special metal rod that is placed across your fracture to keep it in position. Or, the surgeon may attach plates and screws to the outside of the bone to hold the bone fragments together. In some cases, you may need a bone graft with bone taken from your pelvis or from a cadaver (dead body). Or, your surgeon might want to use an artificial bone filler, which can fill in the gaps between a broken bone.
If the bones have been shattered too much to repair, the pieces may need to be removed, and the knee replaced with a prosthesis (implant).