Presenter: Dr. Casey Jones (RCPSC EM PGY1)
Host: Dr. David Lewis
Ultrasonography or radiography for suspected pediatric distal forearm fractures
Snelling et al., for the BUCKLED trial group
PICO
- Research Question: Is ultrasonography non-inferior to X-ray with respect to ..
- Population: Children and adolescents between 5–15 years old presenting to an ED with an isolated, acute, clinically non-deformed distal forearm injury
- Intervention: Randomization to either POCUS by a trained ED practitioner or radiography for injury evaluation
- Comparison: POCUS vs Radiography
- Outcome: Self-reported physical function of affected arm at 28 days
Background
- Forearm fractures represent 40-50% of all childhood fractures
- Distal third of forearm accounts for ~75% forearm fractures and 20-25% of all pediatric fractures
- Most fractures are buckle fractures, treated conservatively with a wrist splint
- Other pediatric fracture patterns include greenstick, Monteggia, Galeazzi, and Salter-Harris fractures
- POCUS for distal forearm fractures is accurate, timely, and confers no radiation.
- Ultrasonography may be more accessible in low and middle-income countries.
- Is POCUS just as good as x-ray in diagnosing distal forearm fractures in pediatric patients?
Methods
- Bedside Ultrasound Conducted in Kids with Distal Upper Limb Fractures in the Emergency Department (BUCKLED) trial
- Study Design: Multi-center, open-label, noninferiority, randomized controlled trial
- Setting: Four centers in Queensland, Australia (large tertiary pediatric hospital, two large mixed academic hospitals with dedicated pediatric treatment areas within their emergency departments, and one mixed hospital without a dedicated pediatric treatment area)
- Inclusion criteria
- Age 5-15
- Distal forearm injury requiring radiological evaluation
- Ability to follow up (distance from centre, telephone, internet access)
- Exclusion criteria – many, but namely:
- Obvious angulation
- Injury sustained >48 hr prior to presentation
- Compound / open fracture, neurovascular compromise, known bone disease
- Suspicion of non-accidental injury, additional injuries
- Imaging modalities
- X-Ray – minimum 2 views performed by radiography. Classified by treating clinician (not radiologist) into either: no fracture, buckle fracture, other fracture
- POCUS – 6-view forearm POCUS protocol with assessment of secondary signs (Snelling et al., 2020, BMJ)
- POCUS credentialling
- Scans in the study were done by either: nurse practitioner, physiotherapist, or emergency physician
- Training course – 2 hour simulated course with lectures and staged learning (scanning)
- 3 proctored scans on actual patients
- Logbook of total 20 patients with a mix of at least 10 buckle and cortical breach fractures, then image interpretation quiz
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Outcome measures:
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Statistical analysis
- Assumed true between-group difference in PROMIS score of 0 at 4 weeks, with noninferiority margin of 5 points (chosen by experts from trial group)
- Power: 300 participant enrollment outcome data for 224 participants (112 per group) 90% power with one-sided alpha of 0.025
- Primary outcome of PROMIS score at 4 weeks was analyzed for noninferiority of ultrasonography to radiography
- Primary analysis was with linear regression modeling to assess noninferiority of POCUS to radiography
Results
- Participant characteristics (Table 1)
- Well randomized groups for ultrasound and radiography (n=135 each group)
- Primary outcome:
- PROMIS (physical function score) at four weeks showed no difference between ultrasonography and radiography
- Secondary outcomes:
- No difference in physical function scores at week 1 or 8 between POCUS/X-ray
- Parent / caregiver-reported satisfaction (5-point likert scale) appeared to be greater in POCUS group vs X-ray at 4 weeks (0.19 points) and 8 weeks (0.20 points)
- Patients in POCUS group had shorter length of stay in the ED (median difference: 15 minutes), and shorter treatment time (median difference: 28 minutes) versus X-ray group
- No substantial difference between groups in number of follow-up radiography films obtained up to week 8
Authors Discussion and Conclusions
- The authors show that point-of-care ultrasound can be used as an initial diagnostic test in distal forearm injury in pediatric patients, with XR reserved for features suggestive of a diagnosis that leads to casting and follow-up (i.e. POCUS best suited for diagnosing buckle fractures)
- Reduced initial radiography at initial ED presentation, especially in patients with buckle fracture or no fracture.
- A diverse group of health care practitioners (physicians, nurse practitioners, physiotherapists) were trained to use ultrasound for this purpose
- “The present randomized trial examined the feasibility, safety, acceptability, and timeliness of using an ultrasonography-first approach to the diagnosis of clinically non-angulated distal forearm injury in children and adolescents who presented to the emergency department.”
Discussion at journal club
Strengths
- Well powered trial to study their question of non-inferiority of POCUS to XR
- Feasible approach to imaging distal radius, and transferrable to many health professions
- Showed that simple fractures can be initially imaged with POCUS only
Weaknesses
- Children with features of a more concerning fracture (i.e. anything more than a buckle) received x-ray anyway (122 films were obtained in POCUS group vs 375 in XR group)
- To that end, does this study show that POCUS may only be appropriate for simple fractures?
Bottom Line
This was a well-designed and executed study by this group in Australia. This method of diagnosing distal forearm injuries would be helpful in rural or resource-limited settings that don’t have readily accessible X-ray. I will certainly be using this more at the bedside in children with this injury pattern!
Further Reading
View the author’s webinar here
