Knee and Kneecap Problems

Sometimes the kneecap is sitting in an unbalanced way, usually too far toward the outside of the knee. This can cause the kneecap to slip out of the joint or put more pressure on the thighbone and the cartilage in the knee. All of these problems can cause pain.

Tight thigh muscles can also lead to knee and kneecap pain. If the muscles on the front of the thigh (quadriceps) are tight, the kneecap gets pushed hard against the thighbone. Tight muscles on the back of the thighs (hamstrings) force the quadriceps to work harder, which may cause kneecap pain.

Patellar tendonitis (PDF), or jumper’s knee, happens when the patellar tendon becomes inflamed. It is common in children who do repetitive jumping activities, like jump rope or basketball.

Patellofemoral syndrome (PDF) is pain at the front of the knee caused by irritation of the kneecap or end of the thigh. Irritation can be caused by overuse of the knee from a repetitive activity, doing weight-bearing work that puts extra pressure on the joint or from a kneecap that is out of alignment.

In children, spots on the bones around the knee that contribute to growth are weaker than other surrounding bone. If the growth centers (growth plates) become inflamed or irritated, it can cause pain.

When this happens at the top of the shinbone, the problem is called Osgood-Schlatter syndrome (PDF). When it happens at the bottom of the kneecap, it is called Sinding-Larsen-Johansson syndrome (PDF).

Growing children and adolescents, particularly teenage girls, can have pain around their kneecaps. Children whose knees are bent inward – commonly called knock-kneed – also tend to have the problem. So do children with tight thigh muscles.

• Your child is cared for by an orthopedics team, including pediatricians, pediatric orthopedic surgeons, nurse practitioners, physician assistants, nurses and physical therapists.
• To restore your child’s health and function, we often use nonsurgical methods, like physical therapy (PT), including sports PT. We have the largest team of physical therapists in the Pacific Northwest who specialize in the care of babies, children, teens and young adults.
• If your child needs surgery, we have pediatric orthopedic surgeons with expanded fellowship training in sports medicine and the experience to treat knee problems in children and teens.

• We tailor treatment to help your child’s specific problem and consider their age and development. For most cases of kneecap pain, we emphasize physical therapy and home exercise programs.
• When treating a child’s knee problem, doctors must take into account the growth plates on children’s bones above and below the knee. Here, your child’s team has special training in the medical and surgical needs of young people.
• We have the largest group of board-certified pediatric radiologists in the Northwest. If your child needs imaging that uses radiation, we use the lowest amount possible (PDF) to produce the best image.

• We offer several surgical options for children who need more than physical therapy, and we are careful to choose the option that best matches your child’s condition.
• Seattle Children’s surgeons are experienced in minimally invasive surgery of the knee for children and teens.

• Our rehabilitation programs are designed to strengthen muscles around your child’s knee to keep their kneecap aligned and prevent irritation and pain.
• To help your child return to play quickly and safely, we do more than treat their current problem. We focus on preventing repeat or new injuries.
• For your convenience, our doctors see patients at several locations around Washington. Seattle Children’s sports physical therapy is available in Seattle, Bellevue, Everett and Federal Way to make ongoing rehab easier for you.

We will probably take X-rays. We may also take pictures of your child’s legs as they stand still. This will help us spot any tendency in your child toward knock-knees, a condition that makes pain more likely.

If we need more information, we may ask your child to have an:

• MRI (magnetic resonance imaging) scan
• CT (computed tomography) scan 

These imaging tests make pictures that can help doctors:

• See whether there is damage to the cartilage inside the knee.
• Get a better look at the position of the kneecap.

Physical therapy and home exercise programs strengthen muscles around the knee so that the kneecap stays in place.

Exercises to strengthen the muscle on the inside of the front of the thigh (medial quadriceps) are especially important to treating kneecap problems successfully. When this muscle is strong, it helps keep the kneecap tracking correctly.

Children may benefit from surgery to help line up their knees and lower legs if:

• They are severely knock-kneed.
• Their kneecaps tend to slide out of joint (dislocate).

There are a number of surgical approaches to treating kneecaps that tend to dislocate:

• For children who are knock-kneed, temporary staples in the growth plate at the inside of the lower end of the thighbone can correct the problem. This procedure lets the outer growth plates grow while pinching the inner growth plates. This tends to straighten the legs over time and improve the kneecap’s tracking.
• Older children may benefit from an operation that ties the kneecap down to the inner side of the knee. This keeps it from sliding to the side.
• Another option is to move the attachment of the kneecap to the shinbone so that the kneecap tracks better.

Surgery also may be the best treatment if your child has dislocated their kneecap and injured the cartilage covering the joint.

In this operation, the doctor tries to reattach cartilage and bone where the dislocating kneecap has knocked them out of place. This is usually a minimally invasive procedure called arthroscopic surgery (PDF). It is done with small instruments inserted through smaller cuts than traditional techniques.