Diagnosis

During the physical exam, your doctor might move your child's legs into various positions to check range of motion and see if any of the positions cause pain.

Imaging tests

These types of tests, which are vital to the diagnosis of Legg-Calve-Perthes disease, might include:

• X-rays. Initial X-rays might look normal because it can take one to two months after symptoms begin for the changes associated with Legg-Calve-Perthes disease to become evident on X-rays. Your doctor will likely recommend several X-rays over time, to track the progression of the disease.
• MRI. This technology uses radio waves and a strong magnetic field to produce very detailed images of bone and soft tissue inside the body. MRIs often can visualize bone damage caused by Legg-Calve-Perthes disease more clearly than X-rays can, but are not always necessary.