Legg-Calve-Perthes disease

Legg–Calvé–Perthes disease (LCPD, is a childhood hip disorder initiated by a disruption of blood flow to the head of the femur. Due to the lack of blood flow, the bone dies (osteonecrosis or avascular necrosis) and stops growing. Over time, healing occurs by new blood vessels infiltrating the dead bone and removing the necrotic bone which leads to a loss of bone mass and a weakening of the femoral head. Legg–Calvé–Perthes disease (LCPD, is a childhood hip disorder initiated by a disruption of blood flow to the head of the femur. Due to the lack of blood flow, the bone dies (osteonecrosis or avascular necrosis) and stops growing. Over time, healing occurs by new blood vessels infiltrating the dead bone and removing the necrotic bone which leads to a loss of bone mass and a weakening of the femoral head. The condition is most commonly found in children between the ages of 4 and 8, but it can occur in children between the ages of 2 and 15. It can produce a permanent deformity of the femoral head, which increases the risk of developing osteoarthritis in adults. Perthes is a form of osteochondritis which only affects the hip. Bilateral Perthes, which means both hips are affected, should always be investigated to rule out multiple epiphyseal dysplasia. The condition is most commonly found in children between the ages of 4 and 8, but it can occur in children between the ages of 2 and 15. Common symptoms include pain in the hip, knee, ankle (hip pathology can refer pain to a normal knee or ankle), or groin, exacerbated by hip or leg movement, especially internal hip rotation (with the knee flexed 90°, twisting the lower leg away from the center of the body). The range of motion is reduced, particularly in abduction and internal rotation, and the patient presents with a limp. Pain is usually mild. Atrophy of thigh muscles may occur from disuse and an inequality of leg length. In some cases, some activity can cause severe irritation or inflammation of the damaged area, including standing, walking, running, kneeling, or stooping repeatedly for an extended period of time. In cases exhibiting severe femoral osteonecrosis, pain is usually a chronic, throbbing sensation exacerbated by activity. The first signs are complaints of soreness from the child, which are often dismissed as growing pains, and limping or other guarding of the joint, particularly when tired. The pain is usually in the hip, but can also be felt in the knee (referred pain). In some cases, pain is felt in the unaffected hip and leg, due to the children favoring their injured side and placing the majority of their weight on their 'good' leg. It is predominantly a disease of boys (4:1 ratio). Perthes is generally diagnosed between 5 and 12 years of age, although it has been diagnosed as early as 18 months. Typically, the disease is only seen in one hip, but bilateral Perthes is seen in about 10% of children diagnosed. Perthes disease is a childhood hip disorder initiated by a disruption of blood flow to the head of the femur. Due to the lack of blood flow, the bone dies (osteonecrosis or avascular necrosis) and stops growing. Legg believed the cause was impairment of blood supply to the femoral epiphysis, Calvé believed rickets, and Perthes deduced an infection possibly causing degenerative arthritis leads to LCP disease. Currently, a number of factors have been implicated, including heredity, trauma, endocrine dysfunction, inflammation, nutrition, and altered circulatory hemodynamics.Risk factors are not limited to impaired and disproportionate growth, low birth weight, delayed skeletal maturity, short stature, systemic hormonal changes, and low economic index. Although no one has identified the cause of Perthes disease, a reduction in blood flow to the joint is known. The disease is theorized to include the artery of the ligmentum teres femoris being constricted or even blocked too early, not allowing for time when the medial circumflex femoral artery takes over. The medial circumflex femoral artery is the principal source of blood supply to the femoral head. LCP disease is a vascular restrictive condition of idiopathic nature. Symptoms like femoral head disfigurement, flattening, and collapse occur typically between ages four and ten, mostly male children of Caucasian descent. Children affected by LCP disease often display uneven gait and limited range of motion, and they experience mild to severe pain in the groin area. For example, a child may be six years old chronologically but may have grown only four years old in terms of bone maturity. The child may then engage in activities appropriate for a six-year- old child, but lacking the bone strength of an older child, these activities may lead to flattening or fracture of the hip joint. Genetics do not appear to be a determining factor, but a deficiency of blood factors with anticoagulant property used to disperse blood clots may lead to blockages in the vessels supplying the joint. A deficiency of protein C and protein S, which also act as blood anticoagulants, may also exist; if that were the case, their deficiency could cause clot formation in ligamentum teres femoris artery and hinder blood supply to the femoral head. However, no evidence of this has been found; over the years, many theories have been published, but none has stood up to professional research. Over time, healing occurs by new blood vessels infiltrating the dead bone and removing the necrotic bone which leads to a loss of bone mass and a weakening of the femoral head. The bone loss leads to some degree of collapse and deformity of the femoral head and sometimes secondary changes to the shape of the hip socket. It is also referred to as idiopathic avascular osteonecrosis of the capital femoral epiphysis of the femoral head since the cause of the interruption of the blood supply of the head of the femur in the hip joint is unknown.