What is Sever’s Disease?

Sever’s disease, also known as calcaneal apophysitis or calcaneoapophysitis, was first described by Haglund in 1907, although Sever has received more credit for describing the condition.  Sever’s injury (calcaneal apophysitis) is considered to be the dominant cause of heel pain among children between 8 and 15 years.  The typical age of the patient is 8 to 15 years. The condition is most commonly seen in patients who are engaged in sports, including soccer, basketball, and gymnastics.  The average age at onset is 11–12 years.  The condition is common in both boys and girls.  Boys constitute 66% of the patients, probably due to different physical activity preferences compared with girls of the same age.

Research quantifying cause, distribution, and treatment data on Sever's Disease are still lacking.  Though the natural course of the condition is poorly studied, but it appears to run its course within 6–12 months.  Research indicates the natural course of Sever’s injury among physically active boys, in general, lasts longer than 8 weeks. 
The pain is harmless, and disappears without exception after puberty when the apophyseal growth plate is closed.  This common cause of heel pain in adolescents and teenagers was once considered an inflammation of the bone or cartilage; we now know that it's actually a mechanical overuse pain syndrome with a self-limited, harmless outcome.  Recent research evidence replaces the historical hypotheses that the condition is primarily an inflammatory process.  This means use of anti-inflammatory medication may not be necessary.

The true origin of the heel pain of calcaneal apophysitis is a stress microfracture (invisible on x-ray) due to chronic repetitive microtrauma—it's an overuse syndrome that resolves without surgery in nearly all cases.  Contemporary research describes Sever’s injury in terms of mechanical overuse with repetitive microtrauma to the calcaneal apophysis and its growth plate.  As a consequence of the microtrauma, however, it’s possible that an inflammatory process may occur secondarily.  Some researchers relate the injury to forces placed on the Achilles tendon and the calf muscle structures which cause shear stress that affects the bone and tendon structures of the heel.  The recurrence rate is estimated to be 20%.