Hip impingement (also known as femoro acetabular impingement) can occur when the ball at the top of the femur is misshapen, so it jams into the socket when the hip is bent and/or when the front rim of the socket sticks out too far, so the thigh bone bumps it when the hip moves. It also can occur as a result of Legg-Calve-Perthes disease, slipped capital femoral epiphysis, and coxa vara. Hip impingement can affect children and adults and is thought to be a primary cause of arthritis in the hip. Common symptoms related to hip impingement include pain and stiffness in the groin, thigh, or hip as well as limited range of motion in the hip. If left untreated, pain can become more pronounced and occur while performing more activities. To diagnose hip impingement, a doctor will perform a physical examination and review the results of an X-ray, an MRI, and/or a CT scan. Conservative treatment for hip impingement may include resting, changing activities to reduce pain, and taking over-the-counter anti-inflammatory medication. Physical therapy also may be beneficial in relieving pain and improving joint range of motion. If symptoms do not improve and pain becomes unbearable, surgery to relieve the impingement may be necessary.