Sever’s disease—Does it effect quality of life?

Abstract

Background

Sever’s disease is a condition which has been described inconsistently in the literature with respect to pathology, aetiology and management. In particular, the impact of this condition has been overlooked, probably because it is usually self-limiting.

Method

This study used a prospective comparative design study to determine the impact of Sever’s disease on the quality of life of its sufferers.

Results

Three scales – Happiness, Satisfaction with symptoms and Pain/comfort scale – from the POSNA musculoskeletal questionnaire showed significant differences between the symptomatic and control groups.

Conclusion

Although the condition may resolve with time, these results show that it has a considerable impact on children’s lives.

Introduction

Sever’s disease, also known as calcaneal apophysitis, is an inflammation of the apophysis of the heel, which is open in childhood [1], [2]. It is a condition which has been commented upon and looked at in a retrospective fashion, but has not to date been examined in a systematic manner.

The generally accepted anecdotal clinical picture of Sever’s disease is that of an active sport-playing child aged between 10 and 12 years, more often male, often presenting at the beginning of a sport season, often in the midst of a growth spurt, and experiencing pain over the apophyseal area of one or both heels [3], [4], [5], [6], [7]. The child will generally be found to have limited ankle joint dorsiflexion, an underlying biomechanical deformity of variable nature and increased activity will worsen the pain [3], [4], [6], [7], [8], [9], [10], [11], [12], [13]. The pain is often severe enough so that at the end of a sporting activity the child will actively limp to take weight off the affected heel[s] [3], [4], [6], [7], [8].

The actual effect of Sever’s disease on the patient’s quality of life [QoL] has not been investigated in the literature at all, consequently it is not really known if this condition actually impacts on the quality of life of those individuals with this condition and if this condition is truly worth committing resources for treatment.

The aim of this study, as part of a larger project, was to determine if Sever’s disease actually produced any change in the QoL of patients compared to a non-symptomatic cohort.

Sever’s disease, being a self-limiting condition [4], affects quality of life rather than affecting life expectancy [14]. Establishing the effect of this condition on the individual is important in the determination of allocation of health services for treatment. While simple measures such as visual analogue scales can measure individual components of pain, such data does not offer a holistic or global picture of the quality of life effects of a condition [15], [16]. Comparison to an asymptomatic population provides a more appropriate picture of the impact this condition has on children with Sever’s disease. An accepted tool to capture such effects includes questionnaires that can compare the quality of life between the asymptomatic and symptomatic populations. Selection of an appropriate questionnaire was also influenced by the need to capture the musculoskeletal effect of this disorder on QoL factors.

Selection of an appropriate questionnaire began with a literature review of databases using key terms to identify possible QoL measurement tools. From this exercise, 31 questionnaires/health measures were identified and examined for suitability. Of these 31 questionnaires, 27 were subsequently discarded for the reasons outlined in Table 1.

Adult designed questionnaires were discarded as it has been reported that tools designed for adults were inappropriate for administration to children due to their inability to measure known differences in health status and ceiling effects being exhibited in the scales [14]. In addition to this, most of these questionnaires were validated and assessed for sensitivity exclusively on adult populations. Therefore, they could not be assumed to accurately carry over to a paediatric population. Similarly, those designed for specific conditions such as asthma or juvenile rheumatoid arthritis were discarded due to their testing on these specific populations. A Dutch pain measure had not been translated into English and was thus ruled out, and those designed for pain assessment only were thought to give too focused a view on this component of the QoL continuum. The final study listed in Table 1 was still being tested for validity and was therefore considered inappropriate until such testing was complete.

The four questionnaires considered were:

• POSNA paediatric musculoskeletal functional health questionnaire [POSNA] [17].

• Activities scale for kids [ASK] [18].

• Child health questionnaire [CHQ] [19].

• Paediatric quality of life inventory version 4.0 [PedsQL] [20].

The specific attributes of each instrument are presented in the following table (Table 2). The final choice of questionnaire was based upon consideration of these attributes, so that the final questionnaire contained all the elements necessary to accurately measure the baseline level of QoL and allow comparison between the Sever’s and non-Sever’s disease populations.

A comparison of the POSNA, ASK and CHQ [21] displayed less floor and ceiling effects for the ASK and POSNA questionnaires compared to the CHQ and identified that slightly different parameters were measured in their scales. The POSNA questionnaire was chosen as a QoL measure for this research as it was specific for musculoskeletal disorders, and as such would be more sensitive to change than a more generic scale such as the CHQ or PedsQL. As the POSNA questionnaire was designed to be filled out at the assessment point, it was deemed more likely to have a better response rate and less missing items in comparison to the ASK. It was also deemed more appropriate to have a functional health measure rather than a disability measure per se, as many respondents may not consider their condition to be ‘disabled’.

The POSNA questionnaire is a reliable and valid tool [17] designed specifically for assessing quality of life effects of musculoskeletal disorders in child and adolescent populations. Comprising 108 Likert-style items, it produces eight scales relating to various parameters as well as assessing co-morbidities apart from the musculoskeletal disorder in question. Designed for use from the ages of two to eighteen, the questionnaire exists in two versions becoming a self-answering document from the age of eleven; until that age it is designed to be filled in by parents or guardians. Advice sought from the American Academy of Orthopedic Surgeons, the owners of the questionnaire, suggested that use of the older child questionnaire would be appropriate for children under 11, as it was to be administered in an interview format in this study. This was done to satisfy a requirement of Department of Education and Children Services (DECS) and because there were several colloquial American terms within the wording which may have been hard for the subjects to understand. Four of the scales were selected for this study, consisting of:

• Satisfaction with symptoms scale.

• Pain/comfort scale.

• Happiness scale.

• Sport and physical functioning scale.

The other four scales related to upper body motion and transfers, treatment expectations and a global scale that included the upper body components, and hence were deemed irrelevant for the current study.

Satisfaction with symptoms—is a single item comprising a five-point scale asking how the subject feels about spending the rest of their life with their current musculoskeletal condition at the time of the questionnaire.

Pain/comfort scale—is a three-item scale with questions relating to how much pain the subject had in the last week and how much this pain interfered with their activities, both in sporting and daily activities.

Happiness scale—is a five-item scale with questions relating to how happy the subject is with their body, looks, clothes they can wear, general health and ability to do what their friends can do.

Sport and physical functioning scale—is a twelve-item scale with questions relating to whether the subject has been able to take part in normal activities such as climbing stairs, walking various distances and running short distances. Other questions assess participation in various levels of sport such as Physical Education, playing with friends at recess, competitive sports and general playing with friends. The remaining questions relate to whether assistance is necessary for walking or climbing activities.