Sever?s is described as a traction apophysitis. In childhood our bones are made of a cartilage mould of the bone, which over time as we grow slowly turns into a full bone. The reason for this is that it is easier to grow cartilage to the length required, and then back fill with bone later than it is to actually grow new bone. Most bones have a least two growth of bone centres, one by the joint and one making the main body of the bone. In the growing heel bone (calcaneus) the posterior part has a separate growth area where the Achilles tendon attaches. When playing lots of sport, especially football, rugby and hockey, the two areas of bone can be pulled apart, producing pain. Recent evidence has also suggested that the appearance of this condition on MRI (magnetic resonance imaging), appears to indicate that Sever?s is a type of stress fracture. Whether that fatigue stress is from compression or tension remains in debate, and is probably a combination of both.
Sever's disease can result from standing too long, which puts constant pressure on the heel. Poor-fitting shoes can contribute to the condition by not providing enough support or padding for the feet or by rubbing against the back of the heel. Although Sever's disease can occur in any child, these conditions increase the chances of it happening. Pronated foot (a foot that rolls in at the ankle when walking), which causes tightness and twisting of the Achilles tendon, thus increasing its pull on the heel's growth plate. Flat or high arch, which affects the angle of the heel within the foot, causing tightness and shortening of the Achilles tendon. Short leg syndrome (one leg is shorter than the other), which causes the foot on the short leg to bend downward to reach the ground, pulling on the Achilles tendon. Overweight or obesity, which puts weight-related pressure on the growth plate.
The most obvious sign of Sever's disease is pain or tenderness in one or both heels, usually at the back. The pain also might extend to the sides and bottom of the heel, ending near the arch of the foot. A child also may have these related problems, swelling and redness in the heel, difficulty walking, discomfort or stiffness in the feet upon awaking, discomfort when the heel is squeezed on both sides, an unusual walk, such as walking with a limp or on tiptoes to avoid putting pressure on the heel. Symptoms are usually worse during or after activity and get better with rest.
The doctor may order an x-ray because x-rays can confirm how mature the growth center is and if there are other sources of heel pain, such as a stress fracture or bone cyst. However, x-rays are not necessary to diagnose Sever?s disease, and it is not possible to make the diagnosis based on the x-ray alone.
Non Surgical Treatment
Treatment is primarily directed towards reducing the amount of stress to the heel. Often a heel lift, is placed in the shoe to reduce the pull of the Achilles tendon on the apophysis. Gel or cushioned heel cups may also be helpful in reducing micro trauma to the heel. Orthotic control may also be indicated when a pathologic condition exists in the foot that may be contributing to the increased heel stress. Occasionally, it becomes necessary for adequate healing, to rest the area completely. This can be accomplished either by complete elimination of all strenuous activities, or by using a walking cast or crutches. Often simply reducing activity levels is adequate. Your physician will discuss the best treatment plan with you and your child.