OrthoticS for TReatment of symptomatic flat feet In CHildren (OSTRICH): a randomised controlled trial.

Background: Children and young people with symptomatic pes planus (flat feet) often seek treatment from healthcare professionals. There are various treatment options, but there is a lack of high-quality evidence about which is most effective.

Objectives: To assess the clinical and cost-effectiveness of prefabricated orthoses, plus exercise and advice, compared with exercise and advice alone on physical function, measured using the physical domain of the Oxford Ankle Foot Questionnaire for Children, among children with symptomatic pes planus.

Design and methods: A pragmatic, multicentre, two-armed individually randomised controlled trial with an internal pilot, economic evaluation and qualitative study.

Setting and participants: Children and young people aged 6-14 years with symptomatic flat feet were recruited from hospital or community healthcare facilities in England and Wales. Participants were randomised 1 : 1 using a secure web-based randomisation system and followed up for up to 12 months.

Interventions: We planned to provide all participants with advice and exercises, with the intervention group also receiving a prefabricated orthosis. Due to the nature of the study treatments, blinding of participants or the research team was not possible.

Main outcome measures: The primary outcome was the physical domain subscale of the Oxford Ankle Foot Questionnaire for Children over the 12-month follow-up. Secondary outcomes included the physical domain subscale at 3, 6 and 12 months, and the 'School and Play' and 'Emotional' domains of the Oxford Ankle Foot Questionnaire, pain scores, healthcare resource use, EQ-5D-Y and Child Health Utility 9D at all time points. The qualitative study drew on health literacy and health belief perspectives and examined fidelity and explored the experiences of being in the trial for those receiving and delivering the study treatments.

Results: COVID-19 severely delayed trial set-up and recruitment and the study closed before meeting its recruitment target. Of 549 participants assessed for eligibility, 134 were randomised (intervention n = 70, control n = 64). The mean age of participants was 10.6 years (range 6.3-14.8) and 55.2% were male. No adverse events were reported. The planned statistical and health economic analyses could not be fully conducted due to the limited data. The qualitative study identified pain, posture and gait as the most common concerns by participants with pain relief as the primary motivator for seeking health care. Participants generally reported little understanding of their condition with barriers including misattribution (e.g. growing pains). Misinformation was common emphasising a need for accessible accurate education materials and structured follow-up care. There was a common belief that orthoses were superior to exercises leading to high levels of adherence, satisfaction and outcomes with orthoses compared with poor adherence, and low perceived efficacy with exercises linked to challenges incorporating these into daily routines.

Limitations: We could not deliver the study objectives as planned. Due to the limited data available, we were unable to undertake the planned analysis.

Conclusions: The COVID-19 pandemic significantly impacted trial set-up and recruitment. Extending the study was not feasible due to cost and time constraints.

Future work: The evidence for the clinical and cost-effectiveness of orthotics for the treatment of symptomatic flat feet in children remains inconclusive and an area for further research.

Funding: This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR127510.