Ultrasound detection of an occult Rib fracture: A Differential in Left Upper Quadrant Pain - Diagnosis

Discussion:

A plain chest radiograph is the most common imaging modality utilised in patients presenting with chest trauma (1) and rib fractures are the most common thoracic injury sustained (1). However NICE guidelines do not advocate plain radiographs for the detection of non-complex rib fractures (2) due to the stochastic risks of exposure to ionising radiation outweighing the benefits of a radiological diagnosis of rib fracture as well as poor visualisation. Ultrasound is the modality of choice for patients presenting with left upper quadrant (LUQ) pain which includes the lower thoracic region; introducing a grey area in the clinical diagnosis of lower thoracic/hypochondrial pain.

We present a case where targeted ultrasound detected of an occult rib fracture in a patient with blunt force trauma to the left hypochondria.

Recent literature advises that fractured ribs should only be managed with surgical fixation in cases of five or more fractured ribs with a flail segment and on patients requiring continuous positive airway pressure management; however, this rule is not without exceptions (3). When there are no complications secondary to rib fractures then a clinical diagnosis of a fractured rib is sufficient (2). Although small, the stochastic risks of exposure to ionising radiation in non-complex rib fractures outweigh the benefits gained from a radiographically diagnosed fracture as the plain film findings will not change the patient’s management. Conversely multiple rib fractures and possibility of high impact or polyvisceral trauma warrant examination with computed tomography.

Ultrasound is a useful tool in assisting with the diagnosis of rib fractures with some studies claiming that 98.3% of rib fractures were detected on ultrasound in comparison to 45.8% being detected on Posterior-anterior chest radiographs (4). In recent years ultrasound has been of increasing value in the diagnosis of fractures (5) with some studies saying that the sensitivity and specificity in the detection of periosteal reactions can reach around 86.05% and 77.27% (6) which indicates early signs of stress fractures before they are visible on radiographs (6). Ultrasound appearances of fractures include; Discontinuity of cortical alignment, focal haematoma, elevation of the periosteum and increased colour Doppler signal (4,5,7).  The case presented here shows strong concordance with current literature in the sonographic features of fractures.

While ultrasound might be helpful in the detection of fractures (4,6,7) the impact on clinical management for the patient needs to be considered. In the case presented the clinical management remains unchanged – the patient will not require clinical intervention relating to the fractured rib. However, the information gleaned from this scan may increase the clinician’s confidence in their diagnosis and help establish a timeframe for the healing process. In the emergency setting there has been a rise in the use of bed side ultrasound and FAST scanning (8). In addition to the identification of fluid, this increased utility may help to rule out superficial injuries such as rib fractures (9) and underlying visceral injury. These applications both aid the clinicians in their diagnosis and increase confidence in their findings.

This case helps to highlight the importance of targeted ultrasound within the junctional zone of the lower thoracic / hypochondrial region when there is point tenderness and no other abnormality found.

Final Diagnosis: Simple rib fracture

Differential Diagnosis: Clinical Costochondritis

Differential Diagnosis: None

 

References:

  1. Abed-Al, N A., and Yasser, N. (2012) ‘Rib fracture: Different radiographic projections’, Polish Journal of Radiology, 77(4), pp. 1-8, Available at http://www.polradiol.com/fulltxt.php?ICID=883623 (Accessed: 4th October 2018)
  2. National Institute for Health and Clinical Excellence (NICE) Guidelines (2017) Fractures of the Ribs and Pelvis. Available at: http://www.ebm-guidelines.com/ebmg/ltk.free?p_artikkeli=ebm00947 (Accessed: 4th October 2018)
  3. De Moya, M., Ram, N., and Walter, B. (2017) ‘Rib fixation: Who, What, When?’, Trauma & Acute Care Open, 2(1), pp. 1-4 doi: 10.1136/tsaco-2016-000059
  4. Pihbin, E., Ahmadi, K., Foogardi, M., Salehi, M., Toosi, F T., Rahimi-Movaghar, V. (2017) ‘Comparison of ultrasonography and radiography in diagnosis of rib fractures’, Chinese Journal of Traumatology, 20(4), pp. 226-228 doi: https://doi.org/10.1016/j.cjtee.2016.04.010
  5. Amoako, A., Abid, A., Shadiack, A., Monaco, R. (2017) ‘Ultrasound-Diagnosed Tibia Stress Fracture: A Case Report’, Clinical Medicine Insights: Arthritis and Musculoskeletal Disorders, 10(1), pp. 1-3 doi 10.1177/1179544117702866    
  6. Rao, Akhilesh., Pimpalwar, Y., Sahdev, R., Sinha, Shilpa., Yadu, N. (2017) ‘Diagnostic Ultrasound: An Effective Tool for Early Detection of Stress Fractures of Tibia’, Journal of Archives in Military Medicine, 5(2), pp. 1-7 doi: 10.5812/jamm.57343.
  7. Lalande, É., Guimont, C., Émond, M., Parent, M C., Topping, C., Kuimi, B L B ., Boucher, V, Sage, N L S. (2017) ‘Feasibility of emergency department point-of-care ultrasound for rib fracture diagnosis in minor thoracic injury’, Canadian Journal of Emergency Medicine, 19(3), pp. 213-219 doi: 10.1017/cem.2016.383
  8. Smith, Z A., Postma, N., Wood, D. (2010) ‘FAST scanning in the developing world emergency department’, South African Medical Journal, 100(2), pp. 105-108 Available at http://www.samj.org.za/index.php/samj/article/view/3821/2683  (Accessed: 9th October 2018)
  9.  Iraj, G., Farzad, B., Seyyedeh, M P. (2018) ‘Role of Bedside Ultrasound in Detection Of Fractures in Pediatrics and Adults’, Journal of Ayub Medical College Abbottabad-Pakistan, 30(1), pp. 115-118 Available at http://jamc.ayubmed.edu.pk/index.php/jamc/article/view/370/1871 (Accessed: 9th October 2018)

 

Declaration of interests: None