Q: My son is 6 years old. He fell down while playing but did not complain about any pain or injury. After 15 days he complained about pain in leg. On x-ray a minor crack was detected on his right hip joint. Later he started limping and reported pain at hip and knee joint. On consultation with an orthopaedician, it was reported that his right leg is shortening and the condition is called Perthe's disease. The doctor advised traction. What is Perthe's disease? What are its causes and treatment?

A:Perthe's disease is an arrest of the blood supply to femoral head (hip joint) between the age group 4 & 8 years, and the cause is not known. In your son's case, the injury probably was co-incidental. The above disease is self-limiting and takes about 3-5 years to complete its process. The downside is it scars the hip joint in the process. If no proper treatment is meted out during the disease process, the hip can be affected badly. A proper discussion with a paediatric orthopaedic surgeon is advisable.