The most common form of knee fracture is a patella fracture, or fracture of the kneecap. The patella is a small bone in front of the knee joint that protects the knee and connects the muscles in the front of the thigh to the tibia.
Kneecap fractures comprise 1% of all skeletal injuries and can cause significant impairment, as the kneecap is critical in the knee’s movement.
What are the symptoms of a kneecap fracture?
Symptoms for patella fractures depend on the severity and area of the fracture; however, these symptoms are the most common:
- Pain: A sharp pain in and around the kneecap.
- Swelling and bruising: The injured area may be red and swollen, or become bruised.
- Limited movement: Difficulty lifting the leg, bending and straightening the knee, and walking.
What causes a kneecap fracture?
Kneecap fractures are typically caused by either falling directly on the knee or receiving a sharp blow to the knee. One common cause of a patella fracture is the kneecap colliding with the dashboard of a car in an auto accident. Severity of kneecap fractures from a vehicle collision can range from moderate to severe.
Engaging in sports or falling onto concrete can also cause a fractured kneecap, along with sudden movement. Having a muscle imbalance of strong quadriceps and weak hamstrings can result in an excessive amount of force placed on the patella, leading to a fracture.
Patella fractures most commonly occur in people aged 20-50 years old, and occur more frequently in men.
How is a kneecap fracture classified?
A fracture can occur in any part of the patella, according to the NYU Langone, and also can vary in severity, as it can just crack slightly or be fractured into many pieces. Here are some classifications of patella fracture:
Most patella fractures are closed fractures, in which the bone doesn’t break through the skin. These may be treated without surgery in some cases.
An open fracture is when the bone breaks through the skin, exposing the injured kneecap. It must be treated immediately with surgery.
A nondisplaced, or stable, fracture is when the bone breaks into pieces. Usually a closed fracture, in nondisplaced fractures the pieces do not separate and the fragments stay in the same place.
Displaced fractures occur when the patella breaks into separate pieces that become separated from one another. Displaced fractures take different forms, including:
- Simple fracture: A closed fracture with the bone breaking into two pieces that are easy to put back together.
- Comminuted fracture: A fracture that can be closed or open in which the bone shatters into multiple pieces that don’t stay in place.
- Osteochondral fracture: Typically a closed fracture, in this fracture, the cartilage at the bottom of the patella is injured as well.
How is a kneecap fracture diagnosed?
Open fractures are immediately apparent, as the bone will be protruding from the skin, and require surgery. For a closed fracture, the doctor will examine the knee for swelling and try to assess the level of pain. Oftentimes, the edges of the fracture can be felt through the skin, especially if it is displaced. They may ask you to try to extend your knee or lift your leg to determine the degree and area of injury.
After conducting a physical examination, the doctor will order X-rays to see the location of the fracture. They may also order an MRI scan if they believe that the fracture has affected surrounding tendons, ligaments, or other soft tissues.
What is the treatment for a kneecap fracture?
Wearing a knee brace, splint or cast is sometimes recommended when the fracture is not severe. Typically in this situation, you’d also be using crutches or a walker to limit using the injured leg.
An experienced physical therapist can help restore motion in the knee through a variety of exercises, including stretching, weight-bearing exercises, and strengthening movements.
To ease the pain experienced by a kneecap fracture, a physician may recommend over-the-counter pain medications to help during the healing process.
According to Dr. Vladimir Alexander, founding partner of Alexander Orthopaedics, knee fractures, including those in the kneecap, “generally require surgery because the lower limb stabilizes the body for a bearing of weight/walking and running.”
For kneecap fractures, specifically, surgery is typically required in open fractures, displaced fractures, or those involving torn ligaments. If the fracture is less severe, surgery can be scheduled rather than performed immediately, as is the case for an open fracture. The type of surgery performed depends on the type of fracture.
What is the kneecap fracture recovery process?
While all patella fractures may damage the cartilage and therefore generate greater risk of osteoarthritis, osteochondral fractures cause people to possess an even higher risk of knee osteoarthritis.
“Knee fractures can enter the joint surface causing irregularity of the joint. This irregularity of the joint can lead to posttraumatic arthritis of the knee joint unless the irregularity is repaired and aligned correctly surgically,” says Dr. Alexander.
“Such treatment requires 3 to 6 months of limitation of full activity and full weight-bearing. These fractures are common in high velocity/high caliber trauma and can also occur with moderate velocity trauma in patients with osteoporotic bones.”
That’s why undergoing surgery and treatment with an experienced orthopedic team is essential. At Alexander Orthopaedics, we work with you to develop a customized treatment and recovery plan, ensuring you can successfully recover from a kneecap fracture. We’re your partner for your diagnosis, surgery, treatment and recovery.