Dislocated patella

How does a doctor know my child has a dislocated patella?

An evaluation should be performed by a pediatric orthopedic surgeon. During the examination, the physician will obtain a complete medical history of your child. If the dislocated patella resulted from an injury, the physician may ask about how the injury occurred.

During the examination, the physician may ask your child to walk around or to straighten and bend the knee. He or she may carefully feel the area around the kneecap and take measurements to determine if the bones are out of alignment or if the thigh muscles are weak. X-rays may be recommended to see how the kneecap fits in its groove. Your doctor will also want to eliminate other possible reasons for the pain, such as a tear in the cartilage or ligaments of the knee. The following imaging procedures may be used to see the knee:

• X-ray – a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film
• Magnetic Resonance Imaging (MRI) – a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.