Sacral and coccyx radiographs may have limited diagnostic yield in detecting fractures

1. In a retrospective review of over 650 adult patients, radiographs of the sacrum and coccyx demonstrated an overall low positivity rate for detecting fractures and did not appear to alter management or decrease the occurrence of advanced imaging within 30 days, such as computed tomography (CT) or magnetic resonance imaging (MRI).

2. Among patients that demonstrated positive sacral and coccygeal fractures, none required surgical intervention.

Evidence Rating Level: 3 (Average)

Study Rundown: Sacral and coccygeal fractures are often associated with high-energy trauma, particularly in young adults. However, previous literature has demonstrated that sacral and coccygeal radiographs exhibit limited accuracy due to intrinsic anatomical variations, as well as overlying fecal material, and body habitus. Computed tomography is the current imaging standard in cases of high-energy trauma given its increased accuracy for traumatic bony abnormalities, calling into question the use of less sensitive sacral and coccygeal radiographs. The purpose of this retrospective cohort study was to evaluate the clinical value of routine sacral and coccygeal radiographs in the emergency department at both level-1 and level-2 trauma centers in cases of both traumatic and non-traumatic pain.

The study retrospectively reviewed over 650 adult trauma patients from different emergency departments who underwent sacrum and coccyx radiographs. At the conclusion of the trial, the overall positivity rate for fracture was only 8.4% in this cohort. Of all the positive fracture cases, none required surgical intervention. Additionally, there were no significant associations between a positive finding on sacral and coccyx radiographs and analgesia prescription or follow-up clinic referrals, and no significant differences in immediate or 30-day rates of advanced imaging by CT or MRI. This study highlights that sacral and coccyx radiographs for trauma patients are associated with overall low diagnostic yield and subsequent low clinical impact for patient care. The study is limited by its retrospective nature and the relatively small sample size, however, the study supports the elimination of this imaging modality in the emergency department evaluation of sacral and coccygeal fractures.

Click to read the study in AJR

Relevant Reading: Emergency Department Extremity Radiographs in the Setting of Pain Without Trauma: Are They Worth the Pain?

In-Depth [retrospective cohort]: This study retrospectively reviewed all consecutive cases of sacrum and coccyx radiographic examinations between 2009 and 2014 in four hospitals in the United States. All 4 hospitals had either Level I or Level II trauma capabilities. Each radiograph was reviewed for the presence of fracture as positive or negative and a follow-up plan. Overall, 687 patients (mean age: 48.1 years) were reviewed. At the conclusion of the study, 8.4% (n = 58) of sacrum and coccyx radiographs were positive for fracture. Of the 58 patients that demonstrated a positive fracture on the radiographs, no patients received a surgical intervention within 60 days of presentation. Within Level I trauma centers, there were no association between a positive fracture finding on radiograph and clinic follow-up referral or analgesia prescription compared to patients without fracture (OR: 2.3; 95%CI: 0.81 to 6.20). Within Level II trauma centers, a positive fracture finding was associated with increased analgesia prescriptions and clinical referrals (OR: 7.0; 95%CI: 0.94 to 52.50). There were no association between sacrum and coccyx radiographs and the need for advanced imaging within the same emergency department visit.

Image: PD

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