Post pelvic binder radiograph can identify bladder injury associated with pelvic trauma: A multi-centre observational...

As per current British Orthopaedic Association Standards for Trauma (BOAST), all patients presenting with pelvic fractures should undergo a contrasted Computer Tomography (CT) scan and post binder removal X-ray (PBXR). According to those guidelines, retrograde cystography is recommended to investigate suspected bladder injury. However, retrograde cystography is an invasive procedure that is not easy to perform in polytrauma patients. We hypothesise that timely PBXR can show contrast accumulation in the bladder which may help detect bladder or urethra injuries.

This paper evaluates whether patterns of contrast within the bladder or extravasating on the PBXR indicate associated urological injury. It also examines if catheterisation and timing of the PBXR affects diagnostic ability.

Patients with pelvic ring and/or acetabulum fractures were retrospectively identified from Electronic Patient Records of two Level 1 Trauma centres (July 2021 to December 2024). PBXRs were analysed to determine the contrast pattern and to look for extravasation. Patterns were correlated with bladder injury findings from urological investigations or intra-operative findings. Catheterisation and CT-PBXR time interval were recorded.

Of the 601 patients with pelvic fracture, 186 underwent a CT scan followed by PBXR. Five (2.69%) patients had confirmed bladder injury. Contrast extravasation was visible on PBXR in 4 (80%) patients with bladder injury (p < 0.001). Of the 181 patients without bladder injury, none of them showed contrast extravasation and 122 (67%) had contrast visible within the bladder. In patients without bladder injury, 47 (25.97%) were catheterised, which was associated with less commonly seeing contrast filling the bladder when compared to those without a catheter (p = 0.005). PBXR performed within 10 h of CT scan was associated with a significantly higher rate of contrast-filled bladder (85.82%) than those performed more than 10 h after CT scan (14.89%) (p < 0.001). There was also significant correlation between those with a catheter and having a bladder injury (p = 0.021).

Visible contrast extravasation on PBXR correlates strongly with bladder injury associated with pelvic trauma. This is more reliable when patients are not catheterised and PBXR is performed within 10 h of CT scan. Timely PBXR after contrasted CT can identify patients who would benefit from expedited urological referral. Further prospective investigation is warranted.