May 2015

Sever disease: Intervene early to relieve symptoms

5PEDS-heel-pain-iStock3620206-copyOnce pain and inflammation have been addressed, clinicians can implement interventions—including orthotic devices, stretch­ing, and strengthening—to address the biomechanical factors that are believed to contribute to heel pain and other symptoms in this population.

By Erin Boutwell

Sever disease, also known as calcaneal apophysitis, is an overuse injury commonly diagnosed in children, particularly those active in sports such as running1 and soccer.1,2 The primary complaint of Sever disease is heel pain associated with repetitive microtrauma of the calcaneal apophysis. The age range of the children affected is typically 7 to 15 years, corresponding to the time period that starts when the calcaneal growth center appears and ends when it fuses.1,3,4

Sever disease is considered self-limiting, meaning the disease will resolve itself over time (through fusion of the growth center), but that can take years. Because most patients respond to treatment within three to six weeks and are able to return fully to their normal activities,5 experts said early intervention is warranted.

“If you have a child who’s in pain for two years of a twelve-year period, that’s a substantial amount of time, so you do want to jump on it and treat it,” said Alicia James, BPod, MHealth Sci, director of the Kingston Foot Clinic in Cheltenham, Australia, who is currently studying interventions in children with Sever disease as a PhD candidate at Monash University in Melbourne, Australia.3

Approximately 2% to 16% of the musculoskeletal complaints reported in children are attributed to Sever disease, but these data come primarily from sports medicine clinics and therefore are not necessarily representative of the incidence within the general population.1,6

The goal of orthotic management is to reduce shear stress on the apophysis, and, if necessary, realign the foot posture to correct for overpronation.

Possible mechanisms

It is widely accepted that Sever disease is the result of microtrauma sustained during repetitive loading. Beyond that, there is no clinical consensus on what causes this microtrauma.

There are two main schools of thought on the biomechanics behind Sever disease. One theory is that the calcaneal apophysis is placed under traction during this period of rapid growth as the Achilles tendon creates a shear force upward on the heel; the plantar fascia may contribute to this traction by pulling in the opposite direction.3,7 A second potential explanation for the symptoms of Sever disease is damage caused by the repetitive impact forces during heel strike, particularly during high-impact activities.2

Not all Sever patients present with symptoms beyond heel pain. However, some children with Sever disease also present with tight heel cords,8 limited ankle dorsiflexion,1,8 or an underlying biomechanical malalignment.1,8

A prospective study in which investigators compared a group of Sever patients to a control group demonstrated little evidence of these factors, however. The one exception was a significant difference in forefoot position between groups, providing evidence in support of biomechanical malalignment within the Sever disease population.9

“Excessive pronation unlocks the foot, making it a mobile adaptor rather than a rigid lever,” said study author Rolf Scharfbillig, PhD, a podiatrist and lecturer at the University of South Australia in Adelaide. “The calf muscles have to work harder to achieve heel lift as [a mobile adaptor] is less mechanically efficient.”

Diagnosis

The most common clinical diagnostic technique is known as the squeeze test, in which medial-lateral compression is applied to the injured heel in an effort to reproduce the pain. Other techniques include tests for the presence of pain when the patient balances on the affected leg10 or when they do a calf raise.11 However, the squeeze test remains the gold standard for diagnosis.

Radiography has also been suggested as another possible way to diagnose Sever disease, but clinical consensus is that radio­graphy is not necessary for diagnosis. Nevertheless, radiographs may play an important role in ruling out other possible causes of heel pain.7,8,12 In a 2011 study by Rachel et al, approximately 5% of children diagnosed with Sever disease had abnormal radiographic findings.12

Identification of such radiographic abnormalities could result in an amended treatment plan, said study coauthor Derek Kelly, MD, a pediatric orthopedic surgeon at the Campbell Clinic in Germantown, TN.

“Based on the sample used in that article, we recommend a single lateral x-ray of the calcaneus as part of the initial work up for children presenting with a chief complaint of heel pain,” Kelly said.

Treatment options

The first objective of any Sever disease treatment regimen is to minimize inflammation and control the child’s pain. This is typically accomplished by modified rest, ice, and anti-inflammatory medications.7 Once pain and inflammation have been addressed, however, clinicians can begin to implement interventions that address the biomechanical factors associated with Sever disease.

Gabriel Gijón-Nogueron, PhD, a podiatrist and associate professor at the University of Málaga in Spain, summarized the biomechanical goals of treatment in three points: (1) increased contact area beneath the foot to minimize high-pressure areas, (2) raising the heel to reduce the tension on the Achilles tendon, and (3) correcting any biomechanical malalignments such as overpronation. The emphasis on foot posture stems from published reports of pronation in up to 18% of Sever disease patients,13 and clinical estimates that are even higher.

“If the foot is very pronated, it’s possible to see [it]—this movement [causes] tension on the fascia or the Achilles tendon,” Gijón-Nogueron said. He estimated that almost 50% of the patients he sees with Sever disease demonstrate overpronation.

The two main strategies clinicians use to achieve their bio­mechanical goals involve stretching and strengthening programs or in-shoe orthotic devices.

Stretching and strengthening

Stretching and strengthening regimens may include either static or active stretching exercises. They are typically designed to increase ankle dorsiflexion range of motion, stretch out the gastrocnemius and soleus muscles, and reduce strain on the Achilles tendon. Like many other aspects of Sever disease, the effectiveness of stretching programs has not been studied adequately in a controlled environment.

However, Adam Potteiger, ATC, a certified athletic trainer in the Institute for Sports Medicine at Lurie Children’s Hospital of Chicago, and colleagues are conducting a new study in this area.

“We are currently enrolling patients in a study to compare rest [symptomatic care], static stretching, or active elongation exercises as the best treatment,” Potteiger said. “Active elongation exercises involve lengthening the muscle groups by trying to minimize the stress on active growth plates.”

Scharfbillig also emphasized the importance of stretching in ­patients with Sever disease.

“If the patient displays tight hamstrings and/or calves, then these must be stretched as a matter of urgency, as otherwise I have found other treatment options will have little effect,” Scharfbillig said.

Nonetheless, some skepticism exists regarding the effectiveness of stretching routines in Sever patients. Elengard et al in their 2010 article criticized the quality of evidence on stretching programs to date, and suggested that stretching may not be necessary in Sever disease patients who do not demonstrate decreased dorsi­flexion range of motion.11

Orthotic interventions

In-shoe orthotic devices are a common method of Sever disease treatment, and may be used in combination with stretching or pain management therapies. The goal of orthotic management is to reduce shear stress on the apophysis, and, if necessary, realign the foot posture to correct for overpronation.4

The orthotic devices may take various forms, the most common being heel cups, heel wedges, and insoles (prefabricated or custom). Each provides a slightly different method of influencing the biomechanics of the calcaneal apophysis and the surrounding musculature.

A heel cup is used to compress the heel pad beneath the foot and maintain it in a central position with respect to the rest of the foot, maximizing the thickness of the anatomical heel pad beneath the painful calcaneal apophysis.14,15 Also, many heel cups are manufactured out of gels and other viscoelastic materials that provide the patient with additional protection from impact forces.

Jeremy Uronis, CO, an orthotist at Lurie Children’s Hospital of Chicago, said of his own clinical experience treating children with Sever disease, “I can’t think of a good reason not to dispense gel heel cups right off the bat to help reduce pain, discomfort, and possibly even inflammation.”

A heel wedge raises the position of the heel to relieve tension from an overly tight Achilles tendon.14 Alicia James said she believes these wedges (also known as raises) are effective for treatment of Sever disease in patients who do not demonstrate overpronation.

“If you’ve got a neutral foot, then what’s the point of giving them [a full-length] orthotic? A heel raise should and probably would work quite nicely,” James said.

Orthotic insoles can provide much of the same function as heel wedges, but may also be used to correct pronation.14 Gijón-Nogueron provides more than 400 pairs of insoles per year in his clinical practice, and contends that, in his experience, insoles are an extraordinarily effective treatment method for Sever disease, working in just three to four weeks.

Given that each type of orthotic treatment has its supporters, it can be a challenge for practitioners to determine which one is best for each patient. There have been few well-controlled research studies comparing the relative effectiveness of treatments; consequently, there is no current gold standard for orthotic management of Sever disease.1

Insoles fabricated for a boy with Sever disease. (Photos courtesy of Gabriel Gijón- Nogueron, PhD.)

Insoles fabricated for a boy with Sever disease. (Photos courtesy of Gabriel Gijón-Nogueron, PhD.)

Investigators have conducted only one comparative study to date: Perhamre et al reported significantly greater pain reduction with a heel cup than with a heel wedge during sports activity, but the study design was a crossover analysis in which children were able to choose which orthotic device they preferred.14

“Most children prefer the heel cup, but some children choose the heel wedge, and it would be very interesting to know why,” said study coauthor Maria Klässbo, PhD, a physical therapist and researcher at Landstinget i Värmland in Sweden.

Klässbo said she suspects biomechanical malalignment or shoe type might influence children’s preferences.

Practitioners’ opinions about which approach is most successful are incredibly varied, something that has an interesting potential interpretation: Perhaps all of the orthotic interventions are effective at relieving heel pain.

Heel cups, wedges, and insoles are typically fabricated out of viscoelastic materials such as foams, gels, and plastics. All of these materials are able to absorb shock beneath the foot. If impact forces play a larger role in the development of Sever disease than traction of the calcaneus, the addition of any shock absorber beneath the calcaneus might prove to be an effective treatment option.

“It really comes back to that old debate: Is it an impact force, or is it tractional? Yes, there is a tractional component of it,” James said, “but I think the impact is what we’re perhaps not addressing enough.”

Prevention

Given that the mechanism behind Sever disease is unclear,16 identifying children at risk for the condition in the hopes of an early intervention is next to impossible. Another challenge in predicting which children are at risk is that clinicians typically don’t have the opportunity to assess a child’s biomechanics prior to injury.

“It’s most likely not until the patient’s heel starts hurting that they seek treatment,” Uronis said.

Scharfbillig said his prospective study9 suggests that probable risk factors for Sever disease include forefoot or rearfoot varus, flexible forefoot, footwear with inappropriate support, and activity level.

Obesity has also been suggested as a risk factor for developing Sever disease.3 However, Scharfbillig’s study found no difference in the incidence of Sever disease between overweight and normal-weight children.9

Generally speaking, variables that contribute to overuse injuries—including poor sports technique, old or worn-out footwear, inadequate recovery time between training sessions, and a change in the characteristics of the playing surface—may also play a role in Sever disease.8

Going forward

Those who have studied the Sever disease literature agree on one thing: More research is required before a best-practice treatment option can be decided. The results of the first randomized
controlled trial comparing Sever disease treatments (the protocol for which was published in 2010)3 should be published this year, and James has hinted that the results might have a big influence on the typical treatment process.

“You almost have this script of how you’re going to treat something,” James said. “It [the study finding] really does teach me to go back and assess the child and to provide the treatment based on what you see in the child rather than the script.”

Determining which patients will respond to an insole versus a heel wedge is another important area of study, and the deciding factor may be foot alignment (eg, pronation).14 Technological advancements related to methods of quantifying foot posture and alignment should help researchers and clinicians address these issues objectively.9

Like James, Scharfbillig emphasized the importance of effective treatment for children with Sever disease, despite the self-limiting nature of the condition.

“This is a condition that … has a real effect on the child and should be dealt with aggressively, rather than just telling the child they will grow out of it or just stop sport,” Scharfbillig said. “Proper assessment and treatment mean this can be a minor condition, rather than a lingering one.”

Erin Boutwell is a freelance writer based in Chicago.

REFERENCES
  1. Scharfbillig RW, Jones S, Scutter SD. Sever’s disease: what does the literature really tell us? J Am Podiatr Med Assoc 2008;98(3):212-223.
  2. Perhamre S, Janson S, Norlin R, et al. Sever’s injury: treatment with insoles provides effective pain relief. Scand J Med Sci Sports 2011;21(6):819-823.
  3. James AM, Williams CM, Haines TP. Heel raises versus prefabricated orthoses in the treatment of posterior heel pain associated with calcaneal apophysitis (Sever’s Disease): a randomised control trial. J Foot Ankle Res 2010;3:3.
  4. Gijon-Nogueron G, Cortes-Jeronimo E, Cervera-Marin JA, et al. 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):495-498.
  5. Cassas KJ, Cassettari-Wayhs A. Childhood and adolescent sports-related overuse injuries. Am Fam Physician 2006;73(6):1014-1022.
  6. Carter RS. Sever’s disease (what do we really know?). The Podiatry Institute. 2011. Available at http://www.podiatryinstitute.com/pdfs/Update_2011/2011_44.pdf. Accessed April 30, 2015.
  7. Tu P, Bytomski JR. Diagnosis of heel pain. Am Fam Physician 2011;84(8):909-916.
  8. LaBella CR. Overuse injuries unique to young athletes. The Ann & Robert H. Lurie Children’s Hopital of Chicago website. http://www2.luriechildrens.org/ce/online/article.aspx?articleID=101. Published 2005. Accessed April 30, 2015.
  9. Scharfbillig RW, Jones S, Scutter S. Sever’s disease: a prospective study of risk factors? J Am Podiatr Med Assoc 2011;101(2):133-145.
  10. Perhamre S, Lazowska D, Papageorgiou S, et al. Sever’s injury: a clinical diagnosis. J Am Podiatr Med Assoc 2013;103(5):361-368.
  11. Elengard T, Karlsson J, Silbernagel KG. Aspects of treatment for posterior heel pain in young athletes. Open Access J Sports Med 2010;1:223-232.
  12. Rachel JN, Williams JB, Sawyer JR, et al. Is radiographic evaluation necessary in children with a clinical diagnosis of calcaneal apophysitis (Sever disease)? J Pediatr Orthop 2011;31(5):548-550.
  13. Micheli LJ, Ireland ML. Prevention and management of calcaneal apophysitis in children: an overuse syndrome. J Pediatr Orthop 1987;7(1):34-38.
  14. Perhamre S, Lundin F, Norlin R, et al. Sever’s injury; treat it with a heel cup: a randomized, crossover study with two insole alternatives. Scand J Med Sci Sports 2011;21(6):e42-e47.
  15. Perhamre S, Lundin F, Klässbo M, et al. A heel cup improves the function of the heel pad in Sever’s injury: effects on heel pad thickness, peak pressure, and pain. Scand J Med Sci Sports 2012;22(4):516-522.
  16. James AM, Williams CM, Haines TP. Effectiveness of interventions in reducing pain and maintaining physical activity in children and adolescents with calcaneal apophysitis (Sever’s disease): a systematic review. J Foot Ankle Res 2013;6(1):16.
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