Legg-Calve-Perthes disease, or Perthes disease, is a condition where the top part of the thigh bone temporarily does not get adequate blood supply. This causes the ball-shaped part of the hip bone to die. This condition occurs in children and the cause is often unknown. It is considered rare, affecting only about 1 in 1,200 children, according to Children's Hospital Boston. If caught early enough, bracing, medication and sometimes surgery can help to manage the symptoms until blood supply returns to the hip. When the blood supply returns to normal, the hip can grow new bone. If the clinical signs of Legg-Calve-Perthes disease appear, it is important to seek treatment right away. Some patients regain full use of the hip, while others may have some permanent damage.
Limp During Play
Perthes disease tends to occur in athletic children between the ages of 2 and 12 and it affects boys more than girls. The most common early symptom of Legg-Calve-Perthes disease is a limp, states the National Osteonecrosis Foundation. Limping may be more pronounced during physical activity and comes on with no known cause. In some cases, limping may occur without any pain, which can delay seeking treatment. Some children have this condition for some time, until an injury necessitates an X-ray or MRI, which shows the breakdown of the hip bone.
Pain
Children with Legg-Calve-Perthes disease may also develop unexplained knee, hip, thigh or groin pain. These symptoms tend to get worse with activity and resolve with rest. The pain may or may not be accompanied by reduced range of motion in the hip or leg. This condition can affect just one side of the body or both hips.
Leg Length Discrepancy
As the blood supply to the hip is reduced, the head or ball portion of the hip bone begins a degenerative process. The hip joint can become inflamed as the ball portion of the bone becomes less round. This process can take between six months to one year and may result in one leg being shorter than the other.
If the condition occurs and is caught at an early age, X-rays will show the bone reforming and returning to its natural shape. Bone reformation can take between one to three years. The goal of treatment during this time is to manage symptoms and keep the hip joint in place until the new bone fully forms.
