Here’s a quick primer on grading spleen injury. It’s only 4 minutes long, so enjoy!
Pelvic bony injury requires substantial force, and there are several distinct fracture patterns seen. Today, I’ll briefly review the so called A-P force mechanism and its grading.
The anterior-posterior (A-P) mechanism frequently results in what many call an “open book” pelvis on x-ray evaluation. It most commonly occurs when something heavy rolls over or crushes the pelvis. We see this in patients who have a vehicle roll over their torso, or are crushed by heavy machinery. The force is applied to the sacrum posteriorly and the anterior portions of the iliac crests. This fulcrum effect displaces one or both iliac wings posteriorly. The flexion point is typically the sacro-iliac joint or the sacral wings. The pubic symphysis pulls apart as the iliac wings move away from their anatomic position.
The usual grading system assigns a type subclassification based on the amount of disruption:
- Type I – less than 1 inch (2.5cm) of pubic diastasis, or rami are fractured; no significant posterior injury
- Type II – more than 1 inch of diastasis; one or both SI joints widened; posterior SI ligament intact; anterior SI, sacrospinous and sacrotuberous ligaments torn
- Type III – all anterior and posterior ligaments disrupted
How is this grading system useful? It is generally predictive of hemodynamic instability, resuscitation requirements, and the possibility of concomitant vascular and/or neurologic compromise. However, you can also get a pretty good idea of all of that just looking at the x-ray. But it is helpful in describing the injury to your orthopedic colleagues.
Tomorrow: What to do about it in your trauma bay.
We love our CT scans! They’re so high tech, with such detailed images popping up on the monitor so quickly. To take advantage of the detail, we’ve come up with fancy grading systems that can be used to direct care. But are they all they’re cracked up to be?
CT grading of spleen injury is a prime example. We’ve got a nice, detailed system that looks at laceration depth, subcapsular hematoma size and vascular injury. We can use it to predict the likelihood of needing an operation and where we should admit someone in the hospital (ICU vs ward). And when we see the injury on the screen, we believe that we can accurately apply the scoring system to these beautiful images.
But unfortunately, it’s not that simple.Scanning obtains multiple images in an axial plane and lays them out for us to look at. However, the spleen (and most other organs) and not shaped like a cube. It is curved, with complex nooks and crannies that can look like cracks. Moderate to large hematoma around the spleen can obscure lacerations. And the hilum is even more complicated and variable in shape.
Because of this, CT scans of the abdomen tend to underestimate the true extent of injury, especially in the higher grades. Grade I and II injuries are usually accurate, but in Grades III-V, the scan tends to undergrade by 1 (30% of cases) or 2 grades (45% of cases) when re-graded at surgery.
Bottom line: Grade I and II injuries are generally managed in a lower intensity setting and almost never require operation. But beware of the higher grades! It is very likely that it’s higher than you think. This means that if your patient slowly becomes tachycardic or their blood pressure softens, believe the clinical evidence. Don’t rely on a CT scan that was done hours ago that may be hiding a more severe injury than you think! (This applies to liver injuries as well)
Reference: Correlation of operative and pathological injury grade with computed tomographic grade in the failed nonoperative management of blunt splenic trauma. Euro J Trauma Emerg Surg – Online First 2 Mar 2012.
Spleen injury grading is not as complicated as people think! The grading system ranges from Grade I (very minor) to Grade V (shattered, devascularized).
There is one nuance that people frequently don’t appreciate: multiple injuries can increase the grade. Technically, multiple injuries advance the maximum grade by one point, up to a maximum of Grade 3. So Grade 1 + Grade 1 = Grade 2, but Grades 2+2 = 3! Weird arithmetic!
The vast majority of injuries are Grades 1 to 3, and they are actually the easiest to grade. I use this simple rule: 1 and 3, 10 and 50.
The first set of numbers indicates the depth of a laceration in centimeters.
- Grade 1 – < 1 cm laceration depth
- Grade 2 – 1-3 cm laceration depth
- Grade 3 – >3 cm laceration depth
The second set of numbers refers to size of a subcapsular hematoma in percent of the total surface area of the spleen. Hint: most of these low grades are determined by laceration depth. Very few actually have sizable subcapsular hematomas. So memorize the 1-3 rule first!
- Grade 1 – <10% subcapsular hematoma
- Grade 2 – 10-50% subcapsular hematoma
- Grade 3 – >50% subcapsular hematoma
Grades 4 and 5 use other criteria, but in general if it looks completely pulped it’s a 5, and if it’s a little less pulped, it’s a 4.
- Grade 4 – hilar injury with >25% devascularization OR contrast blush (active bleeding)
- Grade 5 – shattered spleen, or nearly complete devascularization
That’s it! Tomorrow I’ll talk about the real significance of the contrast blush.