Perthes disease, also known as Legg-Calve-Perthes Disease (LCPD), is a disorder that mostly affects children’s hips.1 Perthes disease falls in a group of disorders known as osteochondroses, in which there is degeneration along with ensuing regeneration of epiphyses (growing ends of bones). In Perthes disease, the head of femur is affected, which is shaped as a ball. The femur (thighbone) is connected to the pelvic bone through ball and socket joint, where the head of femur (ball) fits into the socket (acetabulum). This ball and socket joint provides mobility and flexibility to the hips/legs and helps in leg movement to various degrees.
Perthes disease is a result of decreased blood supply to femur head that leads to necrosis and deformity of the femoral head. The cause of decreased blood supply to femoral head is unknown, but theories have pointed toward genetics, malnourishment, thrombophilia (blood clotting disorder) and other environmental factors. The necrosed bone takes several years to heal and regenerate, this condition resolves with the establishment of new blood supply, and a healthy bone is formed in the affected area without any intervention.
The affected child may present with symptoms of a limp with or without pain in hip, knee, thigh or groin. There might also be muscle spasm of leg, muscle atrophy of the thigh, limited movement of the hip along with shortening of the leg.
Is There A Cure For Perthes disease?
The cure for Perthes disease depends on the age of the child and the severity of the condition. Although, Perthes disease resolves on its own without the need of any intervention, it takes about 2-4 years for the necrosed bone to be replaced by a healthy bone. Some children might require intervention depending on the symptoms. Children under the age of 8 years have a better recovery rate than children over 8 years and as the age increases the prognosis becomes poorer. Generally, children have mild forms of Perthes and the recovery is complete without the need of any intervention.
For children who require treatment, the treatment goal is focused on the recovery and growth of femoral head to a normal shape. This goal is achieved with the help of containment concept. This concept is based on the fact that femoral head can be molded while it is healing. The hip socket (acetabulum) is considered as a mold that is used to shape the femur head, as it grows. This is achieved by trying to keep the femur head in hip socket as far as possible and preventing it from slipping out of the hip socket. However, a little movement of the joint is necessary for the optimal nutrition of the cartilage and growth of the bone. The load on the joint is minimized, so that the joint can heal on its own without any deformity. In some cases, the bone heals completely, but in some cases, the bone does not heal completely and require management.
Affected children may require nighttime splinting, home traction and physical therapy. Bracing is recommended for children under 6 years of age and surgery may be the only option for children over 7 years of age with severe forms of the disease. In severe forms of the disease, containment is achieved with surgical intervention. In surgical intervention, realignment is achieved either of the femur, hip socket or both. Realignment of femur is known as femoral osteotomy and realignment of hip socket is known as pelvic osteotomy. In femoral osteotomy, the angle of the femoral neck is changed for it to point toward socket, whereas, in pelvic osteotomy, the angle of the socket is changed for it to better contain the femur.
Follow up is necessary in cases of Perthes disease, as monitoring is necessary to evaluate the signs of osteoarthritis that is very common in these patients. The severity of osteoarthritis is directly proportional to the severity of Perthes disease.