Article Text

Foot orthoses in children with juvenile idiopathic arthritis: a randomised controlled trial
1. Andrea Coda1,
2. Peter W Fowlie2,
3. Joyce E Davidson3,
4. Jo Walsh4,
5. Tom Carline5,
6. Derek Santos5
1. 1Department of Podiatry, The University of Newcastle, New South Wales, Australia
2. 2Ninewells Hospital and Medical School, Dundee, UK
3. 3Royal Hospital for Sick Children, Edinburgh, UK
4. 4Royal Hospital for Sick Children (Yorkhill), Glasgow, UK
5. 5Department of Podiatry, Queen Margaret University, Edinburgh, UK
1. Correspondence to Dr Andrea Coda, Podiatry Lecturer, Health Precinct Building, BE154, PO Box 127, School of Health Science, Faculty of Health Medicine, University of Newcastle, Ourimbah, NSW, 2258, Australia; Andrea.Coda{at}newcastle.edu.au

## Abstract

Introduction There is limited evidence supporting the podiatric treatment of children with juvenile idiopathic arthritis (JIA). This multicentre randomised controlled trial aimed to determine whether preformed foot orthoses (FOs) impacted on pain and quality of life (QoL) in children with JIA.

Methods Eligible children were randomised to receive either ‘fitted’ FOs with customised chair-side corrections or ‘control’ FOs made without corrections. Changes in pain and QoL were measured using a visual analogue scale and Paediatric Quality of Life questionnaire, respectively. JIA children were assessed at baseline, 3 months and 6 months.

Results 60 children were recruited. 179 out of a possible 180 assessments (99.4%) were completed. A statistically significant greater difference in pain reduction (baseline—6 months) was seen between the two groups favouring fitted FOs (p=0.029). The reduction in pain in the fitted FOs group was clinically important (8 mm). Significant differences in QoL favouring fitted FOs were also identified as measured by the children and independently by their parents/carers.

Conclusions Fitted FOs may reduce pain and improve QoL in selected children with JIA.

Trial registration number NCT02001844.

• Rheumatology
• Paediatric Practice

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### What is already known on this topic

• Foot orthoses appear to be effective for children with lower limb pathologies. Currently, there is limited evidence supporting the podiatric treatment of children with juvenile idiopathic arthritis.

• This research adds new evidence on the effectiveness of foot orthoses in treating lower limb issues with juvenile idiopathic arthritis children.

## Introduction

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood and adolescence and may generate short-term and long-term disability.1 Gait analysis in children with JIA has shown significant difference compared with healthy children with regard to kinematics and temporal data.2 Children with arthritis have been shown to be physically less active compared with healthy children.3

In children, foot orthoses (FOs) have been found to improve parameters of gait although little research has been carried out on participants specifically with JIA.4 The use of preformed semirigid FOs may represent a cheaper option than plaster of Paris (POP) casted FOs. Previous studies with JIA reported that POP custom-made FOs were very expensive and that it took between 1 and 2 months before the fitting appointment.5 In contrast, preformed FOs can be supplied to children on the same day as the initial biomechanical assessment.

Current good clinic practice in JIA management supports early active intervention in an attempt to minimise long-term deformities.6 If of proven benefit, early provision of FOs would be in line with this approach.

### Hypothesis

The study aimed to test the hypothesis that in children with JIA, fitted FOs are more effective at reducing pain and improving quality of life than control orthoses.

## Methods

This was a multicentre single-blinded randomised controlled trial (RCT). Ethical approval was obtained from Queen Margaret University, NHS Lothian and NHS Tayside (REC ref no: 09/S1101/21). Children were eligible if they met defined criteria (box 1).

Box 1

### Trial inclusion and exclusion criteria

Inclusion criteria

• Diagnosed with juvenile idiopathic arthritis (any subtype) according to International League of Associations for Rheumatology criteria

• Lower extremity joint involvement with disease onset ranging from 5 to 18 years

• Previous failure of orthotic management in which the patient has not worn any foot orthoses (FOs) for a period of at least 3 months

• Ability to walk a minimum of 15 m or more without assistive devices

• At least 6 months after start of disease modifying antirheumatic drug therapy

Exclusion criteria

• Inability to walk barefoot or shod

• Concomitant musculoskeletal disease, central or peripheral nerve disease and endocrine disorders

• Previous foot surgery

• Currently using FOs

• Where supply of FOs is contraindicated

The participants were recruited from the Paediatric Rheumatology Department of the Royal Hospital for Sick Children, Edinburgh, and from the Paediatric Rheumatology Clinic in Ninewells Hospital, Dundee, in 2011 and 2012. After obtaining informed consent, children were randomised in blocks of 10 each by an online computer random number generator (http://www.randomization.com) to wear fitted FOs or control FOs. Slimflex-Plus(Slimflex-Plus: Algeos (UK), Sheridan House, Bridge Industrial Estate, Speke Hall Road, Liverpool, L24 9HB, UK) FOs were adopted as the intervention ‘fitted’ FOs. The control FOs was made with leather board (1 mm) without corrections. Both FOs had the same black-ethylene vinyl acetate (EVA) top-cover (0.75 mm) to allow for blinding and monitoring the level of adherence to wearing the FOs. The same chief researcher made the fitted FOs at the time of enrolment into the trial. Patients were advised to wear their FOs gradually for the first few days and then to use them in all footwear at all times including during exercise.

The primary outcome was pain reduction as measured by a visual analogue scale (VAS). The VAS for pain is a horizontal line, 100 mm in length. The parents/carers of the participating children were asked to mark on the line the point representative of the current pain level experienced by their children.7 A clinically important change in pain is said to have occurred if there is more than 8 mm difference in recorded VAS between different intervals.8 Change in quality of life as measured by questionnaire was also considered using Paediatric Quality of Life questionnaire (PedsQL), a validated tool for use in children with arthritis and their parents/carers. The children and their parents/carers completed questionnaires independently. Scores closer to 100 reflect a better quality of life. A clinically important change in quality of life is said to have occurred if the PedsQL changes by more than 5 points between different intervals.9 Outcomes were assessed at baseline, 3 months and 6 months.

For a 5% two-sided t test with α=0.05 and power 80% for a RCT design with baseline and two postintervention observations, and a moderate effect size, it was estimated that a total of 46 JIA children would be required (23 controls and 23 trial).10 ,11 The study was overpowered to an estimated 30 participants per group to allow for potential dropouts during the 6-month data collection period. Given uncertainty around the potential for recruiting to the trial, block randomisation was used to limit the risk of biased allocation in light of either poor recruitment or the study finishing early.

### Data analysis

Statistical differences between the control and trial groups were compared at three time points (baseline, 3 and 6 months). All data showed a non-parametric distribution and hence a Mann–Whitney U test was used for the pairwise comparisons. χ2 Test was undertaken only for nominal drugs data.

## Results

Funding allowed recruitment to take place over 1 year. In all, 60 children were recruited in that time: 31 were randomised into the fitted FOs group and 29 into the control FOs group. At baseline, there was no statistical difference between the two groups (table 1). Overall, 179 out of a possible 180 assessments were completed (99.4%) and accounted for statistical analysis.

Table 1

Juvenile idiopathic arthritis (JIA) children characteristics

A statistically significant greater difference in pain reduction between control FOs and fitted FOs favouring the fitted FOs group was achieved between all three intervals. A clinically important reduction in pain was seen between baseline and 6 months in the fitted FOs group of children (tables 2 and 3). A statistically significant greater improvement in quality of life between control FOs and fitted FOs favouring the fitted FOs group was achieved between some intervals (table 2). A clinically important improvement in quality of life was seen between baseline and 6 months in the fitted FOs group of children (tables 2 and 3).

Table 2

Comparison of the change in scores for pain and QoL between the two groups

Table 3

Descriptive statistics indicating the median (IQR) data at 3rd and 6th month for visual analogue scale (VAS), PedsQL paediatric rheumatology and PedsQL parent rheumatology

## Discussion

This was a randomised trial with an appropriate blinding and a virtually complete follow-up of 60 children with JIA. The results are likely to be valid and as well as reaching statistical significance have also shown clinically important differences that favour the use of fitted FOs.

Pain investigation using VAS reached clear statistical and clinical significance over the 6-month period favouring fitted FOs. Although it is noted that the baseline pain score in the fitted FOs group of children appears higher than in the control group—median VAS 14 versus 6.5—this difference does not reach statistical significance and does not necessarily invalidate the finding of a greater reduction in pain in the fitted FOs group of children. A small unequal number of recruited children at baseline within different JIA subtypes, particularly for the Oligoarthritis group, can be noticed. However, statistical analysis was conducted accounting all the subgroups together, and not stratifying each JIA subtype individually, which would have otherwise required a significant higher number of participants for this RCT. In addition, although multiple outcome measures were recorded and this is sometimes regarded as a feature that might compromise the findings in clinical trials, all the other comparisons that showed significant differences between the two groups of children favoured fitted FOs thereby strengthening the conclusion that fitted FOs are potentially of benefit in managing children with JIA. The ‘positive’ findings also included outcomes assessed by both the children and their parents/carers again adding weight to the conclusion that fitted FOs are of benefit.

The fitted FOs used in this study were supplied at chair-side on the day of the initial biomechanical assessment. The participants received podiatric intervention immediately compared with previous studies that used the older style of POP custom-moulded FOs, where the participants had to wait 1 or 2 months before the fitting appointment.5 In a previous study of children with JIA, the cost of the POP custom-made FOs was $250–$350 (£160–£230) for each pair12 whereas in this study the estimated cost of the FOs used was £10–£15. It was therefore possible for the patients in this study to benefit from the FOs’ apparent positive effect immediately and at minimal cost, complying with the philosophy of early intervention adopted by the multidisciplinary team in paediatric rheumatology. Finally, a double-blind or triple-blind randomised methodology would have been more robust, compared with a single-blinded RCT. Further research is needed into the effects of FOs for a longer period of time and with more JIA children.

## Conclusions

Fitted FOs may reduce pain and improve quality of life in children with JIA. This pragmatic study provides new evidence that supports early management in JIA children with chair-side customised FOs that are cheap and can be fitted quickly. With this approach, children with JIA can receive immediate podiatric intervention, which is well tolerated by the children, on the same day as the initial biomechanical assessment. Further research is however required into the potential long-term benefit of fitted FOs beyond 6 months.

## Acknowledgments

Dr Andrea Coda would like to thank all the children and their parents who took part in this research for their precious time.

## Footnotes

• Contributors All authors have made substantial contributions to all of the following: conception and design of the study, acquisition of data, analysis and interpretation of data, drafting the article, critically revising the article for important intellectual content, and final approval of the version to be submitted.

• Funding Queen Margaret University—Edinburgh (part of PhD scholarship).

• Competing interests None.

• Patient consent Obtained.

• Ethics approval NHS Lothian; Queen Margaret University, Edinburgh; NHS Tayside.

• Provenance and peer review Not commissioned; externally peer reviewed.

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