Sever Disease

Anatomy

For descriptive purposes, the foot is divided into three areas: forefoot, midfoot, and hindfoot. The hindfoot contains two bones, the talus and the calcaneus. The calcaneus contains a vertically oriented C-shaped growth center located in the back of the heel. The growth center appears around age 5 to 9 and usually closes by age 13 to 16, when the calcaneus has achieved its mature adult shape. An additional cartilaginous growth center, the calcaneal (“traction”) apophysis, is located where the Achilles tendon attaches to the bone.

Causes

Sever disease was originally described as an inflammatory process occurring within the calcaneal apophysis. Another proposed etiology was disruption of the blood supply to the growth center. Now, Sever disease is believed to be the result of repetitive mechanical stress applied to the apophysis by a tight heel cord (Achilles tendon) in an overactive young athlete.

This repetitive impact and shear stress on the growth center leads to microtrauma and injury at the junction of the bone and cartilage. This may occur during periods of rapid growth, such as a growth spurt, when the calf muscles and tendons cannot lengthen as quickly as long bones such as the tibia. An increased amount of athletic participation, including longer-duration, higher-intensity, and increased frequency of activities, contributes to the repetitive loading of the heel with weight-bearing activity. Sever disease does not occur after puberty, once the cartilage growth center fuses to become bone.

Symptoms

Sever disease is most common in active children 8 to 12 years old. It is slightly more predominant in boys. It presents with intermittent or daily heel pain and occurs on both feet in more than 50% of children. There is usually no history of an acute fall or direct injury to the heel. The child may describe the pain as located over the heel, and it may be severe enough to cause a limp, especially after participating in physical activity. While the pain may be present at rest or with daily activities such as walking, it is generally made worse with weight-bearing activities, such as running and jumping in sports activities. While all sports can make the symptoms of Sever disease worse, sports such as soccer, basketball, and running are common culprits. Heel pain may present at the beginning of a sports season or when the child is experiencing a growth spurt. The pain is usually absent in the morning, increases with activity during the day, and decreases with rest. Hard surfaces, such as a basketball court, or athletic shoes with little support and cushioning, such as soccer cleats, may worsen the symptoms.

Diagnosis

On physical examination, the most common finding is pain with compression of the inside and outside of the heel (the “squeeze test”). There should be no swelling, redness, or other skin or bone abnormalities. Usually, the gait is normal, but the child may walk with a limp. Many children also have a decreased flexibility or tightness of their calf muscles, resulting in limited dorsiflexion, the ability to pull or stretch a foot toward the head. The strength of the calf muscles is normal. Foot abnormalities such as pronation and flat feet may be present and worsen the condition. The child should otherwise be healthy, with no night pain or other signs or symptoms of systemic disease.

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