Children who present with patellofemoral instability will have a thorough physical evaluation. A knee exam will be performed to evaluate the kneecap position and watch how it moves as the knee is bent and straightened and when your child walks or changes positions. In addition, they will have an overall evaluation of the limb alignment, muscle strength, and the clinician will take into consideration of any other medical conditions that might contribute. These other conditions could be loose ligaments in the body, imbalance of muscle strength, or any other developmental or congenital differences.

At the time of the visit the clinician will decide if imaging is needed, which is usually an X-ray to see the bone. In some children, but not all, they may recommend an MRI. Most of the time the clinician will start treatment right away with a referral to physical therapy and bracing. They will also provide instructions to assist with mobility at school and temporary limitations for gym class and sports. Crutches may be recommended if there is concern of deep injury to the bone (such as a crack or fracture) or if walking is difficult.

The clinicians at U-M Health have a collaborative approach with physical therapists and communicate about progress and improvement in the knee and make sure the teams all agree when it is time to allow activities and sports. And if the knee is just not getting better the team will share that information as well.

In some instances when patellofemoral instability is severe, the clinician might recommend surgery. Our surgeons are nationally known for their expertise in this condition. The surgical steps will be individualized to the child based on the severity of the condition, their age and how the kneecap glides and moves in the body. For all children, the goal is to improve the function of the knee, so the pain goes away and the child gets back to doing the things they love to do.

To make an appointment, please reach out to our team to schedule with one of our knee experts. At your first appointment we will start with a comprehensive history and physical exam as well as obtain any needed x-rays. Your clinician will discuss your goals, and an individualized care plan will be created.

• View information on general sports injury prevention
• View information on pediatric patella dislocations

• Knee shifting or being unsteady: A partial or full slip may be associated with a sense of the knee being unsteady or buckling. It can cause the leg to give out. In severe cases it can lead to a fall.
• Knee clunk or slip sensation: The kneecap can slide out of the groove and clunk. This can cause pain.
• Knee locking: If the kneecap slides out of place it may get stuck and need to be put back. This can also be associated with a visible deformity.
• Knee swelling: The kneecap slipping can irritate the inside of the knee joint and cause internal bleeding which leads to a swollen knee joint.
• Pain: the kneecap slip can bruise the bone inside the knee and stretch tissue when is
  slides. This can cause pain around the kneecap.

The provider will perform a comprehensive exam asking about your child’s symptoms, medical history, and physical activity levels.
Next, the clinician will perform a physical exam, which may include:

• Palpation (feeling around the knee and leg), range of motion, knee stability and strength testing.
• Your clinician will examine leg alignment and watch your child move the knee or walk to determine if they suspect improper strength or alignment as a cause.

Other Tests: At times, to confirm the diagnosis and rule out other possible conditions, your child might need additional tests. These tests may also be used to create an individualized treatment plan, especially if surgery is being considered.

1. X-rays: This is a picture of the bone. It will show if there are any bone problems or alignment issues in the knee joint. It’s a simple and quick test that can help rule out fractures (cracks in the bone), significant malalignment, or other bone-related issues.
2. MRI (Magnetic Resonance Imaging): If the provider is looking to better see the internal structures of the knee joint an MRI might be ordered. It is used to look for damage to structures such as cartilage or ligaments. It also shows the knee joint in 3 dimensions which is helpful for understanding how the kneecap functions in the knee.
3. CT (Computed Tomography): This scan is a test that helps to look at the bones and alignment closer if there are concerns for significant malalignment. This also shows the bone in 3 dimensions.

Often treatment is conservative (nonsurgical):

• Rest and Activity Modification: Sometimes crutches are needing if walking is difficult. Reducing activities that put pressure on the knee give the knee time to rest. This will allow any swelling or pain to resolve.
• Physical Therapy and Home Exercise: A physical therapist can teach exercises that strengthen the muscles around the knee to help stabilize the kneecap. Stretching the muscles, especially those around the hip and thigh, are important for overall flexibility. Exercise both at physical therapy and/or at home are important to prevent repeat events.
• Ice and Elevation: Applying ice packs for 15-20 minutes after activity can help reduce swelling and pain.
• Knee Bracing or Taping: In some cases, these can help to support the knee and while recovering.
• Medications: Over-the-counter pain relievers like ibuprofen or acetaminophen can help reduce pain and inflammation. Topical anesthetics can also help with severe pain.
• Proper Sports Preparation: Make sure to increase activity levels gradually once you are cleared by your clinician to get back to activities.

Surgical Treatment

1. Repeat dislocations: If the kneecap repeatedly slides out of place your clinician may recommend surgery, so it does not continue to happen. The type of surgery may vary based on age, the unique anatomy of the bones, muscles, and ligaments of the knee. The procedure may include building a ligament to hold the kneecap in place. In some people the surgery may also involve lengthening tight structures that pull the kneecap out of place.
2. Loose body: If there is concern of a chipped piece of bone or cartilage (called a loose body) floating in the knee after the kneecap slips, surgery may be needed to repair or remove it. This is often treated by making small pokes in the skin and inserting a camera into the knee joint (arthroscopy). It is often followed by the surgery to hold the kneecap in place to prevent another kneecap dislocation.
3. Severe Malalignment: If the clinician notices severe malalignment, a surgery may be recommended to prevent future problems in the knee later in life. In children who are still growing, this could be a minimally invasive surgery to guide the growth into proper alignment, and in those who are done growing it may be a surgery to realign the bone.

Our team has cared for thousands of children with patellofemoral instability. We have specialized expertise in both non-surgical and surgical management. Our providers are national and international experts in the surgeries for this condition, and we actively participate in some of the leading research looking to better understand and treat patellofemoral instability in pediatric patients.