Diagnostic yield of multiple X-ray imaging requests of lower limb extremities.

Objectives: The diagnosis pathway for patients presenting in the emergency department with lower limb trauma injuries requires adequate medical imaging of the regions of interest. Due to concerns of concurrent injury or overlapping symptoms, X-rays of multiple lower extremity regions may be requested simultaneously. This paper explores the diagnostic yield of imaging multiple lower limb regions following trauma.

Methods: A retrospective audit of lower limb imaging requests for patients older than 18 years from two hospitals was conducted. Region requested, clinical history, and radiology findings for initial and secondary requests for adjacent body parts within 24 hours were collected and analysed using Chi square.

Results: There were a total of 1473 examinations with 646 patients. Initial X-rays were significantly more likely to diagnose new, suspicious, and other findings compared to secondary X-rays of adjacent regions (χ2(3)=377.504, p < 0.001). Overall, 12.4% (n = 183/1473) of X-rays detected abnormalities such as fractures, and 160 of these 183 abnormalities (87.4%) were detected on the initial X-ray with the remaining 23 abnormalities (12.6%) detected in secondary X-rays. Only 0.9% (n = 6/646) of patients had a concurrent injury.

Conclusion: X-ray imaging of multiple lower extremities adjacent to injured areas has low diagnostic yield. Thorough clinical assessment is needed to reduce low-value imaging in lower limb trauma.

Advances in knowledge: Concurrent injury in lower limbs injuries is rare. When multiple X-ray requests are made of adjacent regions, 87.4% of all abnormalities were detected on initial imaging. The diagnostic yield of secondary X-rays is very low particularly when patients are asymptomatic.