O.K. Legg Perthes disease is considered a rare disease that usually boys age 4-10 can develop. The ratio of boys to girls is 3 to 1. This disease causes the blood vessels that travel to the top of the leg where it fits in the hip joint to shutoff for a period of time. Due to lack of blood flow to this area the round part of the bone that fits in joint space deteriorates.. Sometimes the whole head of this bone dies sometimes it is milder. The doctors have no idea why this happens. All studies that show links have studies that say the opposite. Theories are trauma, virus, steroid use, heredity, smoking, protein difficiencies. This disease also causes stiffening of the muscles in the leg. Therapy can usually reverse this but sometimes the tendons are cut and stretched with a brace. Depending on how much of the bone deteriorates, the healed bone can grow back normal or misshaped which will lead to surgery. The long term effects can be arthritis later in the hip and early hip replacement. This happens when the disease is more severe and the bone does not heal well. The length of the disease is usually 2-5 years with the following phases.
1.Restriction of blood flow
2.Evidence on x-ray of ball getting smaller or flattening
3.Deterioration evident on x-ray
4.Reossification of bone (healing)
5.Healed bone sometimes normal sometimes not which means it has grown back too large or not round.
The deterioration usually last about 8 months and the bone growing back can last 2-? years. My sons case seems to be mild so far. He has lost almost 50% of bone and may be in the healing stage. The only diagnosis for this disease is 1.symptoms which are limping, groin,knee, or upper thigh pain, muscle tightening, and muscle loss. 2.Evidence on x-ray. My son had fairly extensive blood work done 3 different times which came back fine before x-rays confirmed Perthes. I hope I have given enough info. Any questions please ask.
Rachelle