The following symptoms commonly presents with calcaneal apophysitis or Sever disease:

• Pain and swelling at the posterior heel [5]
• Walking on toes
• Pain is aggravated with use of heel [6]
• Limping
• Difficulty in running and jumping
• Tenderness when the sides of the heel are squeezed

Patients with Sever disease are usually diagnosed by means of a thorough clinical history and physical examination which demonstrates the characteristic pain in the foot.

Diagnostic tests like radiographic test may be used to rule out concomitant illness that could be potentially serious and present similarly to calcaneal apophyisitis [7]. The following imaging techniques are implored in patients carrying a high suspicion of Sever disease:

• Radiographic X-ray: This procedure will demonstrate any lesions like stress fractures in the calcaneum or bone cysts. It is a tool which is neither diagnostic nor prognostic in Sever disease.
• Computed Tomography (CT) Scan: This set of x-ray beams elucidates the tarsal area and differentiates calcaneal apophysitis or Sever disease from a rare clinical disorder called tarsal coalition which is the failure of the hind bones to physiologically separate. 
• Magnetic Resonance Imaging (MRI): This radiographic imaging modality may elucidate the bones and the muscles clearly; thereby ruling out possible osteomyelitis from Sever disease. 

It should be understood that athletic children who starts at a younger age may fall victim to overuse syndrome of the foot due to increasing frequency of use through practice and actual sport. For this reason, growing child athletes are more prone to Sever disease than the other children in their adolescence [8].

Treatment is primarily focused in reducing pain symptoms, overcoming limitations of movement, and prevention of recurrence. Patients with Sever disease may need to rest for at least 2 months for recuperation before they resume back to sporting activities. The affected foot may be placed on top of a half an inch inner sole lift or molding orthoses to stretch the calf muscle persistently and prevent it from abruptly pulling or straining the calcaneal attachment [9].

Pre-activity and post-activity icing may also prevent apophysitis swelling after an event. Oral antiinflammatory medications may be used to control pain in the heels. Reports on the use of ketoprofen gel in heel pain among children have shorten recuperation time to 18 days [10]. In severe cases of Sever disease may benefit from a 2 to 3 weeks of casting in mild equinus orientation of the foot. Physical therapy may help allay the symptoms and reduce recurrence rate of Sever disease.

By definition, Sever disease is an affliction of childhood which resolves beyond 15 years old due to the complete ossification of the apophysis of the heel.

Any incomplete healing and microfractures by the apophysial line will spontaneously resolve with the bone formation. Stress fractures and bone cysts however may coexist with Sever disease and present symptoms in the same way. Both conditions may persist beyond 15 years old and may need surgery or rehabilitation if they chronically persist with some discomfort.

Complications

There has been no evidence so far that Sever disease can cause any long term pathology or complications to affected children.

The basic etiology involved in Sever disease is stress and overuse upon the calcaneum during physical activities like prolonged running, persistent straining of the calf muscle and continuous impact during jumping.

These foot mechanics are typically seen among children involved in soccer, tracks, and basketball. Obese and overweight children can cause undue strain on the heel bone and cause the disease.

Flat footed individuals with biomechanical defects or biomechanical malalignment on the natural plantar arch may inherently pull on the calcaneal attachments and cause perennial inflammation of the apophysis [2].

There are no available statistical data on the international incidence of Sever disease but it is commonly seen among growing children worldwide. There are no mortalities associated with Sever disease.

The long term pain felt in the heel can essentially limit the child’s range of activity from his sports performance to his daily simple chores. Sever disease has a predilection to male children with a ratio of 13 males to 7 female patients. An Irish study reveals that the average age of presentation was 11.83 years old among boys and 8.67 years old among girls [3].

The pathophysiology of Sever disease is mainly due to the continuous stress exerted on the apophysial line which affects the fragile cartilages that are still starting to ossify. It is well established that the apophysis are formed with more fibrocartilage than the epiphysis of the long bones; thus, they are less resistant to persistent axial stress [4].

This undue stress causes microfractures which radiographically appear as resorption, fragmentation and diffuse sclerosis that may eventually lead to healing. Although clinical evidence of fragmentation does not necessarily mean fractures in Sever disease because ossification center in the rapid spurt of puberty may appear in multiple site at the same time.

The incidence of Sever disease can be significantly prevented in a child when the risks are identified early. The following preventive measures may help a child overcome the risk for Sever disease and prevent heel pain:

• Weight control: Parents must help their children control their weight. Overweight and obese children are more prone to the disease.
• Use of the proper supportive shoes: Children who are flat footed may benefit with the use of supportive shoes that maintains the plantar arch. For those who has experienced heel pain, an inner sole lift may keep the calf muscles stretched and firm.
• Cleated athletic shoes must be avoided.
• Children must not be forced to perform beyond his capacity.

Sever disease or calcaneal apophysitis is a clinical disease characterized by the swelling of the heel bone. The inflammation of the calcaneum is due to the frequent pulling of the gastrocnemius (calf muscle) on the calcaneal insertion where the bone is not totally mature yet. Sever disease is presently classified under the non-articular osteochondroses type of disease for adolescents and children [1].

This disease condition is common among athletic or active adolescents between the ages of 9 to 15 years old. Sever disease is the most common cause of heel pain in children in one or both heels. Unlike adult heel pain that is relieved by walking around, pain in calcaneal apophysitis does not resolve in this manner. Sever disease may cause heel discomforts for months in children and may resolve once the calcaneum bone matures fully.

Definition

Sever disease otherwise known as calcaneal apophysitis is the inflammation of the heel due to the chronic stress provided by the calf muscle on the immature heel bone.

Cause

Stress and overuse of the heel, obesity and overweight children, faulty footwear, Pes planus (flat foot) contribute to this condition.

Symptoms

Heel pain, and limitation of movement, impaired sporting performance  pain in squeezing the heel may occur.

Diagnosis

Diagnosis is mainly by clinical history and physical examination. Imaging techniques are implored to rule out other problems

Treatment and follow-up

Rest, use of supportive footwear, pain relievers, casts and rehabilitation. Patients should have regular visits with their physicians to prevent recurrence.

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2. Scharfbillig RW, Jones S, Scutter S. Sever's Disease: A Prospective Study of Risk Factors.J Am Podiatr Med Assoc. 2011; 101(2):133-45 (ISSN: 1930-8264)
3. Micheli LJ, Ireland ML. Prevention and management of calcaneal apophysitis in children: an overuse syndrome. J Pediatr Orthop. Jan-Feb 1987; 7(1):34-8.
4. Tu P, Bytomski JR. Diagnosis of heel pain. Am Fam Physician. Oct 15 2011; 84(8):909-16.
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9. Gijon-Nogueron G, Cortes-Jeronimo E, Cervera-Marin JA, García-de-la-Peña R, Benhamu-Benhamu S, Luque-Suarez A. Foot orthoses custom-made by vacuum forming on the non-load-bearing foot: preliminary results in male children with calcaneal apophysitis (Sever's disease). Prosthet Orthot Int. 2013; 37(6):495-8 (ISSN: 1746-1553)
10. White RL. Ketoprofen gel as an adjunct to physical therapist management of a child with Sever disease. Phys Ther. 2006; 86(3):424-33 (ISSN: 0031-9023)