SGEM#415: Buckle Down for some Ultrasound to Diagnosis Distal Forearm Fractures

Reference: Snelling et al. Ultrasonography or radiography for suspected pediatric distal forearm fractures. New England Journal of Medicine June 2023 Date: July 19, 2023 Guest Skeptic: Dr. Casey Parker is a Rural Generalist that includes in his practice emergency medicine, anesthesia, and critical care. He is also a fully-fledged ultrasonographer. Casey currently splits his time between Broome, a small rural hospital in the remote Kimberley region of Western Australia, and a large tertiary ED in sunny Perth. He has been a guest skeptic on the SGEM multiple times. He is also the creator of the amazing #FOAMed website, Broome Docs. Dr. Casey Parker Case: It is a steady Saturday afternoon in your rural emergency department (ED). The triage nurse calls you to have a look at a child who has arrived with his parents in ED after falling from a bouncy castle at a birthday party.  He is six years old and appears to be in pain with his left wrist swaddled in an ice pack.  He tells you that he was attempting “a double backflip like Spiderman” when he landed heavily on the outstretched hand - this happened about an hour ago. Clinically there is some swelling and tenderness over the distal radius but no deformity.  He has good perfusion and no neurological symptoms in the hand. Because it is a small, rural ED there is no radiographer on site but they can be called in if we would like to get an X-ray…. or there is a portable bedside ultrasound machine in the next room ready to go. The child’s mother tells you that the X-ray tech was also at the party having a great time with her children. So, the question is: should we call in our x-ray tech in and disrupt her party fun or just use the ultrasound machine to diagnose this possible fracture? Background: We have covered pediatric wrist fractures a few times on the SGEM. This includes SGEM#19 way back in 2013 reporting a bandage wrap is a safe alternative to traditional casting for children with greenstick fractures. More recently, the amazing Dr. Tessa Davis covered the FORCE trial on SGEM #372 which looked at buckle fractures and compared immobilization in a cast or splint vs. a soft bandage and they found no difference in pain scores or functional outcomes. The use of bedside ultrasound to diagnose uncomplicated wrist injuries in children has been studied in several diagnostic prospective, observational trials to compare its accuracy to traditional plain film X-rays [1-5].  Most of these trials have shown diagnostic sensitivity and specificity above 90% when compared to X-ray as a gold standard.  This same research team from Queensland in Australia have also published a paper describing the learning curve for novices in detection of forearm fractures in kids [6].  In 2022 Mobasseri et al published a review of 9 such diagnostic studies and concluded that from an orthopedic perspective that the accuracy was not acceptable, the lack of a randomized controlled trial meant that there was not enough data to support the use of ultrasound over X-ray as an initial diagnostic test [7]. There have been no randomized trials that have compared the patient-centered, functional outcomes after a wrist injury based upon the choice of initial diagnostic test modality. Clinical Question: In children with non-deformed distal forearm injuries, does the use of ultrasound as an initial diagnostic test result in inferior functional outcomes? Reference: Snelling et al. Ultrasonography or radiography for suspected pediatric distal forearm fractures. New England Journal of Medicine June 2023 Population: Children between 5 and 15 years of age who presented to the ED with an isolated, acute, clinically non-deformed, distal forearm injury for which imaging for a suspected fracture was indicated Excluded: obvious angulation/deformity (soft tissue swelling allowed), injury >48hr prior, external X-rays obtained, known bone disease, concern for non-accidental trauma, additional injuries requiring X-rays, congenital forearm abnormality, no credentialed clinician available, developmental delay or behavior prohibiting clinical assessment Intervention: Bedside ultrasound carried out and interpreted by a trained clinician (doctors, nurse practitioners and physiotherapists) Comparison: X-ray Outcome:  Primary Outcome: Functional outcome at four weeks (± 3 days) post injury as measured by the Patient-Reported Outcomes Measurement Information System (PROMIS) score Secondary Outcomes: PROMIS scores at 1 week and 8 weeks post injury.   They also analyzed the children by age cohorts 5 to 9 years and 10 to 15 years old There was also an analysis of the diagnostic accuracy of the ultrasound vs. X-rays. Satisfaction at 4 and 8 weeks (5-point Likert scale with lower scores indicating greater satisfaction) Pain at 1, 4, and 8 weeks using the FACES pain scale Frequency of complications Frequency of radiography Length of stay and treatment time in the ED Trial: Multicenter, open-label, noninferiority, randomized, controlled trial Authors’ Conclusions: “In children and adolescents with a distal forearm injury, the use of ultrasonography as the initial diagnostic imaging method was noninferior to radiography with regard to the outcome of physical function of the arm at 4 weeks.” Quality Checklist for Randomized Clinical Trials: The study population included or focused on those in the emergency department. Yes The patients were adequately randomized. Yes The randomization process was concealed. Yes The patients were analyzed in the groups to which they were randomized. Yes.  The study patients were recruited consecutively (i.e. no selection bias). No.  The patients in both groups were similar with respect to prognostic factors. Yes All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No All groups were treated equally except for the intervention. No Follow-up was complete (i.e. at least 80% for both groups). Yes  All patient-important outcomes were considered. Yes The treatment effect was large enough and precise enough to be clinically significant. No Financial conflicts of interest.  No Results: They randomized 270 patients. Primary outcome data at 4 weeks was available for 130 patients in the ultrasonography group and 132 patients in the radiography group. The average age of patients was around 10 years with 90% of them being right hand dominant. There were slightly more male patients in the radiography group (57% vs 50%). Most common mechanism of injury was fall on outstretched hand. Key Results: Ultrasonography was noninferior to radiography as a diagnostic test in terms of functional outcomes at 4-weeks following wrist injury in children. Primary Outcome:  Secondary Outcomes: Functional outcomes were not statistically different at each of the time points. Ultrasound did appear to be better than X-ray in terms of parental satisfaction, length of time in the ED and time away from school. Although the patients randomized to ultrasound initially had about one third as many X-rays on the initial visit, there was a similar number of x-rays performed at follow-up visits Patient Oriented Outcomes: We were pleasantly surprised at all the patient-oriented outcomes in this study: function, pain, satisfaction of both caregivers and patients, missed school days.  We were not quite sure about the satisfaction rating. This was rated on a Likert scale of 1 to 5 and they found that there was greater parent/caregiver satisfaction in the ultrasonography group at follow-up at 4 weeks and 8 weeks. But why? Were they happy because the person performing the ultrasound explained things nicely? Were they happy because ultrasound didn’t expose the child to radiation? Were they happy simply because someone spent more time with them while performing the ultrasound? Selection Bias: One of the exclusion criteria for this study was obvious angulation or deformity on clinical exam. There is a degree of subjectivity in determining deformity. Additionally, soft tissue swelling was allowed. Would we all agree? This study did end up including some patients with angulated fractures. Clinically deformed wrists are in a way easier. We know that they are going to be broken and might need manipulation.  So, by excluding this group the authors are selecting a cohort with more subtle injuries.  However, this is a subjective inclusion criterion.  It may not matter though as all the children got some form of imaging. Clinical Significance of Injuries: Forearm injuries occur on a spectrum from a little bone “bruise”, through a buckle and then the nasty dinner fork fractures.   We have learned from trials like the FORCE trial that there must be a point on this “injury spectrum” where interventions like plaster casts or splints will have no benefit over “do nothing care”.   However, splints are not benign, so applying them to every kid with a tiny cortical breach will almost certainly result in unnecessary immobilization and some degree of temporary loss of function. There’s also the possibility that a poorly applied splint may cause skin breakdown. Or if the child gets the splint wet, it results in them coming back to the ED. It may be that ultrasound is less sensitive than X-ray, but that this does not matter as the injuries we do not see on ultrasound are unlikely to benefit from immobilization. In this trial there were more splints placed on kids in the group who were X-rayed at the initial visit. However, the kids who were found to have a buckle or torus injury did receive a splint in this trial.  And yet there was no difference in functional outcomes. So, maybe it really does not matter what we do in the first instance? The BUCKLED TRIAL and the FORCE trail were recruiting kids at the same time.