This This 44 year old male has presented to the Emergency Department following a fall from his roof. He has severe pelvic pain, particularly on the right side. The patient was referred for a pelvis X-ray examination.

Has the patient suffered any bony injury as a result of his fall? What supplementary views may be useful?

There is a clearly visible fracture of the right inferior pubic ramus (1). Pubic ramus fractures almost invariably occur in pairs. It is also noteworthy that there is asymmetry of the obturator foramen. The suspicion of a right superior pubic ramus fracture is very high. On close examination, there is a lucency lying medial to the right acetabulum (2). This is indeed the expected fracture of the right superior pubic ramus.

In much the same way as you would expect paired fractures to occur in the pubic bones, the pelvis also approximates a ring of bone and satisfaction syndrome should not prevent further examination of the bony pelvis. Fractures of the sacrum are the most commonly missed fractures in pelvic trauma and warrant close examination. The sacral foramen should appear with continuous smooth cortical margins. On close examination, there is a cortical step in one of the left sacral foramen which is almost certainly part of a larger sacral fracture (3)

The soft tissue outlines adjacent to the hip are asymmetrical. This may be associated with a distended right hip joint capsule (4).

The radiographer performed Judet’s views to provide further information as to the nature and extent of the acetabular component of the right superior pubic ramus fracture. Interestingly, these views hid the fracture spectacularly. This is not to decry the value of the Judet’s views, but rather to acknowledge that fractures can occur in almost any plane and that Judet’s views will not always provide new information.

A CT examination of the patient’s pelvis was performed confirming the plain film findings. In addition, a well defined lesion with sclerotic margins was seen adjacent to the right sacro-iliac joint(5).

The fractured sacrum was not as clearly revealed on the CT pelvis images (note circa 1997 CT scanner). The radiographer identified the sacral fracture and performed a dedicated AP sacrum view which, like the Judet’s views, did not help visualize the sacral fracture

Dr Lee Rogers has developed the “ring bone paired fractures rule’ into what he has described, with great wit, as the Pretzel-bagel Spectrum. If you google Pretzel-bagel Spectrum all will be revealed.