Perthes’ disease, also known as Legg-Calve-Perthes’ disease, was described by Legg, an American, Calve, a Frenchman, and Perthes, a German, around 1910. This disease is characterized by loss of circulation to the head of the femur (the ball of the hip) in a growing child resulting in avascular necrosis (death of bone cells in the head of the femur). This is typically followed by revascularization over a period of 18 to 24 months. During the period of revascularization, the bone is soft and prone to fracture under pressure, causing collapse of the head of the femur. Over time, the head of the femur heals and remodels in the collapsed position, resulting in a non-spherical shape, which leads to stiffness and pain.
In the U.S., one in 1,200 children younger than 15 years old is affected by LCP, and males are affected 4-5 times more often than females. LCP is most commonly seen in persons aged 3-12, with a median age of 7 years.
When a child presents with acute pain in the hip or groin, mild or intermittent pain in the anterior thigh or knee, or a noticeable limp, an x-ray is usually taken. Children with LCP often have delayed bone age, resulting in short stature. In the early stages of the disease, the x-ray may appear to be perfectly normal; however, in the later stages of fracture and collapse, the x-ray will be quite diagnostic. Once the diagnosis of LCP is confirmed, a decision has to be made whether to institute active treatment, and if so, what kind of treatment. The goal of treatment is to maintain as normal a joint as possible so as to avoid early degenerative arthritis.
The natural history of LCP is such that many children have a good outcome without any active treatment, although this prognosis varies with the age of diagnosis. If the onset of the disease is before age 6, the outcome tends to be good, regardless of treatment. As age of onset goes up, the results are not always satisfactory. There are other factors which affect long term prognosis and your pediatric orthopaedic surgeon can speak with you about his.
If treatment is needed, a number of options are available. In the past, bracing and even casting has been used though present day treatment more often involves surgery. The goal of surgery is to keep the ball of the hip covered by the socket. Legg Calve Perthes disease can be a serious condition which requires expert care.