What is the distal femur?
The knee is the largest weightbearing joint in your body, and the distal femur makes up the top part of your knee joint. The ends of the femur are covered in a smooth, slippery substance called articular cartilage. This cartilage protects and cushions the bone when you bend and straighten your knee.
How does a distal femur fracture happen?
Distal femur fractures most often occur during high-energy trauma in young patients and low-impact injuries in older patients. When the distal femur breaks, both the hamstrings and quadriceps muscles tend to contract and shorten. When this happens the bone fragments change position and become difficult to line up with a cast.
What are the most common types of distal femur fractures?
- Transverse fractures – straight across the bone
- Comminuted fractures – bone is broken into multiple pieces
- Intra-articular fractures – extend into the weight bearing surface of the joint and disrupts the cartilage surface. These fractures are more complex and difficult to treat, and the management is largely surgical as these fractures tend to displace even in a cast.
What are the symptoms?
The most common symptoms of distal femur fracture include:
- Inability to bear weight
- Swelling and bruising
- Tenderness to touch
- Deformity — the knee may look "out of place" and the leg may appear shorter
What are the treatment options for distal femur fractures?
Nonsurgical management is reserved for stable, minimally displaced, and non-articular fractures. Other indications include non-ambulatory patients with additional comorbidities presenting with significant anesthesia/surgical risk. Conservative management consists of splinting, bracing, or skeletal traction to prevent shortening. Surgical treatment of distal femur fractures consists of internal fixation, with intramedullary nailing or plates and screws.
