This study compares the clinical outcomes of treating pediatric Type 1 supracondylar fracture with a long arm soft cast and no clinical or radiographic follow-up versus the standard treatment in a long arm cast with clinical follow-up.

This is the first multicenter randomized control trial looking at the clinical effectiveness, safety and parental satisfaction of managing inherently stable Type I supracondylar fractures without clinical or radiological follow-up. If found to be safe; children can be managed effectively without in-person follow-up, freeing clinic appointments to children on the waiting list and in these COVID times avoiding unnecessary contacts.

PURPOSE The purpose of this study is to compare the clinical outcomes and parental satisfaction of treating pediatric Type I supracondylar fractures with a long arm soft cast and no clinical or radiographic follow-up versus standard treatment in a long arm cast with clinical follow-up.

HYPOTHESIS We propose that with clear instructions given to parents in the form of a clinical consultation at soft cast application and written instructions, a Type I supracondylar fracture can be managed with no significant change in pain, without formal in-person clinic consultation, that the treatment will proceed without any negative consequences and the treatment will be met with high parent satisfaction.

JUSTIFICATION The limiting of unnecessary patient visits, X-rays and interactions has taken on a new importance with the ongoing COVID-19 pandemic. Any research that can limit unnecessary risk to our patients, parents and families in terms of contacts should be considered and implemented now more than ever.

OBJECTIVES Our objective is to determine whether Type I supracondylar fractures can be managed safely and effectively without clinical and radiographic follow-up x-rays.

With the COVID-19 pandemic, there has been an increased need to minimize patient interactions for the safety of patients and healthcare workers alike. Typically, these fractures can be managed with minimal intervention. A cast is applied primarily to alleviate pain and the child is required to return to the hospital to have the cast removed.

A soft cast provides adequate immobilization of the fracture but can be removed at home by parents. If this can be shown to provide equivalent pain relief and a similar safety profile then there will be clear benefits at this time in limiting in-person visits and thus potential COVID-19 contacts. In a non-COVID-19 period, there will also be secondary health economic benefits by reducing out-patient follow-up visits.

If our study proves there are no negative consequences then this treatment regime could be simply and rapidly implemented at centers around the world. Additionally if successful it could also be potentially applied to the management of other undisplaced and stable fractures, which would have a considerable impact on the interactions and unnecessary contacts.

RESEARCH DESIGN This study is a prospective multicenter randomized control trial evaluating patients treated with a consistent protocol assessing clinical effectiveness, safety and parental satisfaction with the management of Type I supracondylar fractures with a period of casting and no in-person clinical or radiographic follow-up compared to cast and routine follow-up (standard current practice).

STATISTICAL ANALYSIS All baseline and relevant center and demographic information will be summarized between trial arms via appropriate summary statistics (medians and IQRs for continuous variables and counts for categorical variables).

The primary outcome and any other continuous outcomes will be assessed with a mixed effects model with a random intercept for study center, and a single covariate for treatment group. The coefficient from this model represents the estimated mean difference between groups and will be reported with a 95% confidence interval. Binary outcomes such as unplanned return to hospital will be analyzed similarly with mixed effects logistic regression and odds ratios and 95% confidence intervals will be reported.

As the objective is to show that no follow up is not inferior to standard of care, we prespecify a 20% margin of difference as clinically equivalent for the primary outcome of difference in the pain scale between groups (i.e. 2 points on 10-point scale). Therefore, if the lower bound of the 95% confidence interval from the mixed effects model lies above 20% of the mean, we will treat this as confirmation of non-inferiority. If the entire interval lies within +/- 20% this will be taken as equivalence.

Effect modification of the comparability in the primary outcome between groups will be assessed by including interaction terms with relevant baseline risk factors. Sensitivity analyses will be based on the inclusion of patient and center level covariates thought to impact the primary outcomes and multiple imputation for missing outcomes due to possible differential follow up between groups.

Analyses will be conducted using R statistical software, and a significance level of 0.05 will be used for all analyses. A formal statistical analysis plan will be finalized by all investigators prior to.

Inclusion Criteria:

- Children 3 to 8 years of age with a diagnosed supracondylar humerus fracture Type 1 (undisplaced).

Exclusion Criteria:

• Children diagnosed with a Type II or III supracondylar fracture or any other elbow injury
• Children who present with neurovascular compromise associated with their fracture
• Children who have been previously diagnosed with a metabolic or structural bone disease that predisposes them to fractures

Diagnostic criteria for a Type I supracondylar fracture will include either:

A) A clear fracture line through the supracondylar region with no displacement or angulation of the distal humerus (including a normal anterior humeral line that intersects the capitellum) OR B) The absence of a clear fracture line but history of an extension injury to the arm AND tenderness at the elbow AND local swelling AND presence of a posterior fat pad on plain radiographs.