PELVIC FRACTURE case1
What does this radiograph show, and how would you manage this?
This radiograph shows a vertical shear type injury to the pelvis. This is typically the result of a highenergy injury, such as a road traffic accident or a fall from heights, and the possibility of other lifethreatening injuries must be actively searched for using an ATLS approach to systematic diagnosis and management.
- What would you expect to find on examination?
As part of the ATLS assessment it is possible that embarrassment to any and several body systems might be identified during the concurrent assessment and resuscita tion of the patient. If there is an isolated injury to the pelvis, the patient may very well be distressed due to pain and potentially confused or agitated due to haemor rhagic shock. Additionally, there may be tachypnoea, tachycardia and hypotension.
On inspection, there may be an apparent leg length discrepancy in a vertical shear fracture where one hemipelvis is displaced proximally.
With regard to urogenital and rectal examinations, I would inspect for blood at the urethral meatus, as well as scrotal/labial/perineal haematoma, which may sug gest significant urological trauma.
I would also inspect the state of the soft tissues in order to rule out an open frac ture and to exclude a Morel–Lavallée lesion.
Moving onto palpation, a vaginal examination and rectal examination (in the supine position) to rule out a surreptitious open fracture is mandatory. I would pal pate for a highriding prostate (another sign of significant urethral injury) and anal tone/sensation to assess the sacral nerve roots.
I would also perform a full neurovascular examination of the lower limbs.
I would advise against ‘springing’ the pelvis as a method of diagnosing a pelvic fracture as this is painful, may disrupt a clot which is preventing torrential haemor rhage and is superfluous in the presence of an AP pelvic radiograph taken as part of a trauma series.
- In the absence of a CT, what additional radiographs might give you a better appreciation of the bony injury, and how would you obtain these?
Two views are utilised to better visualise the pelvic ring. Although rarely used for diagnostic purposes given the ready access to modern CT scanning, these are the views that can be achieved with an image intensifier in theatre.
The first of these is an inlet view: The xray beam is angled approximately 45 degrees caudal, and an adequate image is obtained when S1 overlaps S2. This view is ideal for diagnosing widening of the SI joints, sacral ala impaction fractures, subtle pubic symphyseal injuries, as well as internal/external rotation or anterior/ posterior translation of a hemipelvis.
The second is the outlet view: To obtain this, the xray beam is angled approxi mately 45 degrees cephalad. An adequate image is obtained when the pubic symphy sis overlies the S2 body. Conversely, this is ideal for visualising vertical translation of a hemipelvis, as well as flexion/extension of a hemipelvis. As this is a true AP radio graph of the sacrum, it is ideal for diagnosing sacral fractures and their location in relation to the foramina.
- How would you classify pelvic fractures?
I would classify these using the Young and Burgess classification of pelvic fractures. This define pelvic fractures into three categories, with subtypes of each. The catego ries are I – anterior posterior compression (APC); II – lateral compression (LC); and III – vertical shear (VS).
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- APC I – Pubic symphysis widening <2.5 cm. This can be difficult to assess in the presence of a pelvic binder however. Can be managed conservatively.
- APC II – Pubic symphysis widening >2.5 cm. There has been disruption of the sacrospinous and sacrotuberous ligaments, as well as the anterior SI ligaments. The strong posterior SI ligaments remain intact and subsequently there is no loss of vertical stability.
- APC III – As per APC II but with disruption of the strong posterior SI liga ments. This results in loss of vertical stability and is indistinguishable from a vertical shear injury radiographically.
- LC I – Oblique or transverse pubic rami fractures, in addition to crush/ compression fracture of the ipsilateral sacral ala.
- LC II – In addition to the pubic rami fractures, there is a characteristic ‘crescent’ fracture of the iliac wing.
- LC III – There is an ipsilateral lateral compression injury and a contralateral open book injury, known as a ‘windswept pelvis’.
- VS – There is complete discontinuity of the sacral attachment to the lower limb. The posterior sacral ring may fail through the SI joint, the sacrum, or the ilium.
- What are the common sources of bleeding in a pelvic fracture?
The most common source of bleeding (approximately 80%) in pelvic fractures is secondary to a shearing injury to the thinwalled posterior venous plexus. Fractures may result in clinically significant blood loss from cancellous bone surfaces.
Arterial injury is a less common source but the arteries most frequently impli cated include the superior gluteal artery (APC pattern), the internal pudendal artery (LC pattern) and the obturator artery (LC pattern).
Although there are several specific sites for bleeding in association with pelvic fractures, one must remain vigilant for other sources associated with the high energy mechanism of injury (intraabdominal, intrathoracic, limbs)