Non-inferiority of Ultrasound for the Diagnosis of Upper Extremity Fractures in Children

Fractures of the upper extremity are common in children. Approximately 200 children with a suspected upper extremity fracture are treated every month in the paediatric emergency room (pER) of the University Hospital of Basel-Stadt and Basel-Land (UKBB).

If a fracture is suspected in the emergency room, two separate X-ray images have to be obtained to diagnose or exclude a fracture, according to the current standard operating procedure (SOP). This procedure has several disadvantages as X-ray imaging exposes children to radiation and transfer to the X-ray facility is time-consuming. Depending on the suspected fracture, the broken limb needs to be positioned for the two separate perspectives of the images, resulting in pain.

Furthermore, this procedure is time-consuming as the work routine of the attending emergency room physician is interrupted once the child is sent to the imaging facility and then returns to the emergency room after the procedure. The time between the request of the examination and interpretation of the results is called therapeutic turnaround time or brain-to-brain time.

X-ray images are interpreted by the pER paediatrician, and treatment is based upon this interpretation. A secondary reading by a paediatric radiologist for quality control is only done later on. This procedure has been adopted by several hospitals internationally.

X-ray interpretation by pER paediatricians has been evaluated by various studies, and the accuracy compared to paediatric radiologist interpretation is around 90% in most studies, with extremes ranging from 84% to 99%. In the past few years, ultrasound diagnosis of upper extremity fractures in adults and children has been studied. However, the evidence of its effectiveness is still limited, and its application in routine care is uncommon.

Ultrasound has several advantages over X-ray imaging. It does not expose patients to radiation; devices are mobile, the examination can be performed in the child's preferred antalgic position without moving the affected limb, it is always available, and it can be executed directly by an emergency room physician.

We aim to demonstrate that ultrasound is at least as sensitive as X-ray imaging and is thus non-inferior to the standard-of-care diagnostics with X-ray.

Secondary outcomes include pain and time necessary for ultrasound vs X-ray If non-inferiority can be confirmed in this study, we expect a change in SOPs to replace initial X ray imaging by sonographic fracture diagnosis for simple fractures of the upper-extremity long bones.

Inclusion criteria

• Patients presenting to the emergency room of the UKBB with a history of acute trauma to the upper extremities and suspected fracture of a long bone
• Age 0-18 years

Exclusion criteria

• Patient needing immediate medical attention (triage score 1 or 2)
• Severely displaced or open fractures
• Patient with neurovascular compromise distally to the suspected fracture.
• Patient with imaging studies obtained prior to the emergency room visit
• Patient with prior fracture of the affected area
• Patient with known allergy to ultrasound gel.
• Patient with suspected 'battered child' diagnosis.
• Unavailability of a study investigator able to perform the ultrasound examination within a reasonable time frame (15 min; see also 3.2).