Author: Louisa Weindruch, DO (Baylor University Medical Center), Allison Harmsworth Smith, MD (Baylor University Medical Center), Chase Forehand, MD (Baylor University Medical Center), Jonathan Brewer, MD, FACEP, FPD-AEMUS (Baylor University Medical Center), and Whitney Potomac, DO, MS, FACEP, FPD-AEMUS // Reviewed By: Jonathan Warren, MD; Steve Field, DO; Alex Koyfman, MD (@EMHighAK); Brit Long, MD (@long_brit)
History of Present Illness:
An eight-year-old female with no significant past medical history presented with her parents to a local emergency department (ED) with left wrist pain after falling from monkey bars onto an outstretched hand. She was given over-the-counter pain medication at home with minimal relief. She continued to report left wrist pain and swelling, prompting the family to bring her to the ED for evaluation. She was otherwise at her baseline state of health.
Physical Exam:
Vital signs included a blood pressure of 114/98 mmHg, heart rate of 114 beats per minute, temperature of 99.1 degrees Fahrenheit, respiratory rate of 22 breaths per minute, and SpO2 99% on room air. On physical exam, the patient was overall well-appearing and in no acute distress. She had swelling and tenderness to palpation over the left distal radius with no evidence of open wounds. Sensation was intact to light touch along the radial, median, and ulnar distributions. She had a 2+ radial pulse and brisk capillary refill. She had pain with movement and limited range of motion of her wrist, however motor function of the radial, median, and ulnar nerves was grossly preserved.
Point-of-Care Ultrasound:
Point-of-Care Ultrasound (POCUS) of the left distal radius was performed. A linear probe was placed over where the patient had maximum area of point tenderness. POCUS revealed disruption of the hyperechoic bony cortex concerning for an acute fracture (Figure 1 and 2).
Figure 1: Sagittal View of Fracture with Surrounding Hematoma. White arrow points to area of cortical bone disruption consistent with fracture.
Figure 2: Transverse view of fracture. White arrow points to area of cortical bone disruption consistent with fracture.
Diagnostic Imaging:
A three-view x-ray of the left wrist was obtained and revealed non-displaced fractures to the left distal radius and left distal ulna. No additional workup was completed.
Figure 4a: Lateral X-Ray, Fractures of Distal Radius and Ulna. Arrow points to an area of cortical bone disruption consistent with fracture. 4b: Anterior Posterior X-Ray, Fractures of Distal Radius and Ulna
How To Perform:
When obtaining images of musculoskeletal structures with POCUS, a linear probe is the ideal probe to use. Its higher frequency allows for easy identification of highly reflective, shallow structures. Bone will appear as a well-defined, hyperechoic line with posterior shadowing on sonographic imaging. We propose utilizing a 6-view protocol, as described in Snelling et. al. The POCUS operator uses the linear probe to visualize the radius in 3 views (dorsal, volar, and medial) and ulna in 3 views (dorsal, volar, and lateral)[1,2]. With the indicator oriented distally, the operator scans proximally and distally in the longitudinal axis to evaluate the bony cortex, looking for any deformities that would suggest a fracture.
Discussion:
Forearm fractures are the most common fracture in the pediatric population, making up 25% of all pediatric fractures, and are frequently seen in emergency departments worldwide [3]. While x-ray has previously been the standard diagnostic test, in recent years evidence has emerged suggesting POCUS may be used as an adjunct. Ultrasound is quick, cost effective, and can easily be performed at bedside. It provides no additional ionizing radiation, an important consideration in pediatric emergency medicine. Additionally, with increased accessibility of handheld probes, ultrasound has also become an important diagnostic tool in resource-limited and austere environments.
There are many advantages to performing POCUS for suspected fractures in children. The interface between bones and the surrounding soft tissue is highly reflective of sound waves, making ultrasound an ideal modality for imaging fractures [4]. Using a linear probe, the operator can easily visualize the hyperechoic bony cortex and evaluate for any cortical abnormalities [4]. In addition to cortical disruptions, literature suggests that there may be other secondary signs to indicate a distal radius fracture, such as a pronator quadratus hematoma or periosteal hematoma [5,6].
A systematic review of 23 studies with over 3,000 children found that ultrasound is both sensitive and specific for identifying forearm fractures [4]. In this review, sensitivity ranged from 91.5% to 100% with the majority of studies achieving sensitivity >95%. Specificity ranged from 84% to 100% [4]. In a similar systematic review of 7 studies, authors found that in the United States, sensitivity ranged from 85% to 100% and specificity ranged from 73% to 100% [7]. They were ultimately able to conclude that the overall accuracy of ultrasound in diagnosing fractures was between 78.6% to 99.5% [7]. Morello et. al also found that ultrasound decreased length of stay in emergency departments, with an ultrasound-first approach shortening the stay by an average of 15 minutes [4]. This is particularly relevant as many emergency departments continue to face long wait times and boarding crises. In another study, patients had fewer missed days of school over a 4 week period compared to the radiographic group [8]. Lastly, 7 of the 23 studies looked at patient discomfort during POCUS and found that it was similar or even less than the pain experienced during x-ray [4]. It is worth noting that there was a broad range of clinicians – including emergency physicians, nurse practitioners, residents, and orthopedic surgeons – who received focused training in performing POCUS for this indication. This highlights the potential for POCUS to be taught to a variety of different clinicians who may evaluate patients within the emergency department.
Notably, some of the strongest data for the use of POCUS in pediatric fractures comes from a randomized-controlled trial out of Australia where 270 children ages 5-15 years old presented with suspected forearm fractures [2]. Utilizing a panel of expert clinicians including emergency physicians, orthopedic surgeons, and radiologists as the reference standard with clinical longitudinal follow-up, POCUS was found to outperform x-ray for the diagnosis of fracture with an accuracy of 97.8% and 83% respectively [2]. Those patients in the POCUS group had greater accuracy, often due to overcalling of fractures in the x-ray group. This led to an important mean of 28 days in plaster casts for 10 children from the x-ray group that may have otherwise been avoided. It is important to note that patients with obvious angulation were excluded and those with abnormalities on ultrasound received additional radiographic evaluation.
Limitations:
The main limitation identified in this study came from occult fractures that were missed on ultrasound imaging. However, no clinically relevant fractures were missed based on longitudinal participant assessment and evaluation of physical functionality at 4 weeks. POCUS is also limited in its ability to determine degree of angulation, which may lead to changes in management. In this study, ultrasound showed increased specificity compared to radiographs (97.9% versus 79.5%) when identifying the presence of any fracture versus no fracture [2]. This suggests that POCUS may be most useful as an initial screening tool, with additional imaging utilized if POCUS is negative or if any complicating factors are present. POCUS was also found to be more sensitive when identifying fracture versus no fracture, as compared to identifying specific subtypes such as cortical breach fractures like Salter-Harris. This is relevant as simple buckle fractures may be managed conservatively, while cortical breach fractures may require reduction, casting, and other management [6]. It is also important to note that POCUS cannot be performed when a splint is in place, thus radiographs are necessary post-reduction. Other limitations may include patient discomfort, soft tissue swelling, operator dependent image acquisition and interpretation, as well as perceived logistical feasibility in a busy emergency department.
Conclusion:
The patient’s fractures were immobilized in a sugar-tong splint which was placed by emergency department staff. She was discharged with outpatient orthopedic surgery follow-up at a local children’s hospital. This case adds to the emerging body of literature suggesting that POCUS may be a clinically significant and impactful tool for diagnosing pediatric fractures. Studies have shown that it can be performed accurately, even with limited training and may be an ideal tool to be implemented even for younger clinicians such as medical students and residents.
Not only is ultrasound important diagnostically, but it has the potential to improve the patient experience by limiting discomfort and decreasing length of stay. In settings with limited resources, POCUS could be used to facilitate shorter wait times and decrease cost. It could also be used in rural or austere environments, where other imaging modalities are not available prior to transport. Future studies could explore the cost benefit of initial POCUS versus radiographic imaging, as well as time to splint in POCUS versus radiographic imaging. Ultimately, this case highlights how POCUS may be used as an adjunct to traditional radiographs in the diagnosis of pediatric distal radius fractures. While more research is needed, current data suggests that using a POCUS-first approach may improve identification of pediatric fractures and lead to improved ED wait times and patient satisfaction.
Consent was obtained from patient’s parent for use of x-ray and ultrasound images.
References:
- Snelling PJ, Jones P, Keijzers G, Bade D, Herd DW, Ware RS. Nurse practitioner administered point-of-care ultrasound compared with X-ray for children with clinically non-angulated distal forearm fractures in the ED: a diagnostic study. Emerg Med J. 2021;38(2):139-145. doi:10.1136/emermed-2020-209689
- Snelling PJ, Jones P, Bade D, et al. Diagnostic Accuracy of Point-of-Care Ultrasound Versus Radiographic Imaging for Pediatric Distal Forearm Fractures: A Randomized Controlled Trial. Ann Emerg Med. 2024;83(3):198-207. doi:10.1016/j.annemergmed.2023.10.008
- de Putter C, van Beeck E, Looman C, Toet H, Hovius S, Selles R. Trends in wrist fractures in children and adolescents, 1997–2009. J Hand Surg. 2011;36(11):1810-1815.e2. Published 2011 Oct 26. doi: 10.1016/j.jhsa.2011.08.006
- Morello R, Mariani F, Snelling PJ, Buonsenso D. Point-of-care ultrasound for the diagnosis of distal forearm fractures in children and adolescents: a scoping review. Eur J Pediatr. 2024;184(1):19. Published 2024 Nov 16. doi:10.1007/s00431-024-05877-w
- Snelling PJ, Jones P, Bade D, Gillespie A, Keijzers G, Ware RS. Ultrasound Secondary Signs for the Diagnosis of Pediatric Distal Forearm Fractures: A Diagnostic Study. Ultrasound Med Biol. 2024;50(6):898-907. doi:10.1016/j.ultrasmedbio.2024.02.015
- Snelling PJ, Keijzers G, Ware RS. Point-of-Care Ultrasound Pronator Quadratus Hematoma Sign for Detection of Clinically Non-Angulated Pediatric Distal Forearm Fractures: A Prospective Cohort Study. J Ultrasound Med. 2022;41(1):193-205. doi:10.1002/jum.15695
- Ahmed AS, Abdelhady AE. Ultrasonography in the diagnosis of pediatric distal forearm fracture: a systematic review. J Ultrason. 2024;24(97):1-8. Published 2024 Nov 8. doi:10.15557/jou.2024.0019
- Snelling PJ, Jones P, Bade D, Bindra R, Byrnes J, Davison M, George S, Moore M, Keijzers G, Ware RS. Ultrasonography or Radiography for Suspected Pediatric Distal Forearm Fractures. N Engl J Med 2023;388:2049-2057. Published 2023 May 31.DOI: 10.1056/NEJMoa2213883
- Waterbrook AL, Adhikari S, Stolz U, Adrion C. The accuracy of point-of-care ultrasound to diagnose long bone fractures in the ED. Am J Emerg Med. 2013;31(9):1352-1356. doi:10.1016/j.ajem.2013.06.006
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