(Or Calcaneal Epiphysitis, Calcaneal Avascular Necrosis, Osteochondrosis)
What is it?
Sever’s disease is a condition affecting children where a plate of cartilage inside the heel bone is damaged. It is a mechanical condition in that it is caused by a problem with the physics and angles of the foot working. It occurs at the ages where the plate is most vulnerable, generally 10 to 14 years of age. It is more common in boys than girls, in athletes and particularly children involved in field sports like soccer, football and cricket. Often it is particularly painful after finishing the game, standing after resting, and the first steps the next morning.
Why does it happen?
In a perfectly functioning foot, when the heel strikes the ground, the cartilage that is sandwiched between two ends of the heel bone is compressed evenly across the whole surface. When the foot rolls in excessively (pronates), the bone is compressed on an angle that causes a shearing stress on the cartilage plate. This causes it to become inflamed, painful and to swell within its very tight space. This can create a serious problem because the end piece of bone is only supplied with blood vessels from the main body of the bone and these pass through the cartilage plate. If the cartilage swells too much, it can close off these vessels and result in avascular necrosis. This is Latin meaning tissue death from lack of blood supply.
As this is a growing child, the bone will repair without too much long term effect but it will be painful for an extended period usually about two years. Obviously, this is to be avoided as no active child wants to suffer pain nor be forced to sit out of sport for two years.
What can be done?
Fortunately, avascular necrosis will almost always have a long lead up time. It is very unlikely that bone will die without several months of increasing pain giving warning of what is to come. Treatment involves using orthotic devices, avoiding specific shoes and ensuring the calf muscles are diligently stretched daily and before any activity. Treatment with the podiatrist is very likely to resolve the problem very quickly.