Tag Archives: pelvic fracture

Pelvis

Early Operative Fixation of Pelvic Fractures And Functional Outcome

Leave a comment

Disruption of the pelvic bones takes a huge amount of energy, and results in significant bleeding and morbidity from other causes. Repair typically consists of surgical fixation, frequently with temporary external fixation in the interim. These patients require intensive therapy postoperatively, with inpatient rehab prior to discharge home.

How well do patients with severe pelvic fractures do in the longer term? The group at the University of Tennessee in Memphis did a lengthy followup study spanning 18 years of severe pelvic fractures treated at their hospital. These patients had sustained fractures with significant bleeding, an open book component, or SI joint disruption with vertical shear.

open book pelvis pre

The authors used phone interviews and a standardized measurement instrument (Activity Measure for Post-Acute Care, AM-PAC) to gauge daily activity of affected patients. They then looked for factors predictive of functional outcome.

Here are the factoids:

  • 401 patients were identified over the 18 year study period
  • Of these only 71% survived (285), and the study documented followup in 145 (51%)
  • Average ISS was 27 (fairly high) and patients tended to be older (mean 53 years)
  • Even after 8 to 20 years, mobility and activity were significantly impaired as measured by AM-PAC
  • Time to fixation was the only identifiable factor that had an impact on decreased mobility or activity

Bottom line: Early definitive fixation of the pelvis was the only variable found that had an impact on future mobility and activity. Frequently, external fixation is applied soon after admission. But remember, your trauma patient is at their healthiest as they roll through the doors of your ED. The sooner they get all of their problems fixed, the better (and safer).

Impact of early operative pelvic fixation on long-term functional outcome following sever pelvic fracture. AAST 2016, Paper 60.

Equipment

What’s The Best Pelvic Binder? Part 2

Leave a comment

Yesterday, I detailed some pelvic binders commonly available in the US. Today, I’ll go through the (little) science there is regarding which are better than others.

There are a number of factors to consider when choosing one of these products. They are:

  • Does it work?
  • Does it hurt or cause skin damage?
  • Is it easy to use?
  • How much does it cost?

It’s difficult to determine how well binders work in the live, clinical setting. But biomechanical studies can serve as a surrogate to try to answer this question. One such cadaver study was carried out in the Netherlands a few years ago. They created one of three different fracture types in pelvis specimens. Special locator wires were placed initially so they could measure bone movement before and after binder placement. All three of the previously discussed commercial binders were used.

Here are the factoids:

  • In fracture patterns that were partially stable or unstable, all binders successfully closed the pelvic ring.
  • None of the binders caused adverse displacements of fracture fragments.
  • Pulling force to achieve complete reduction was lowest with the T-POD (40 Newtons) and highest with the SAM pelvic sling (120 Newtons). The SAM sling limits compression to 150 Newtons, which was more than adequate to close the pelvis.

So what about harm? A healthy volunteer study was used to test each binder for tissue pressure levels. The 80 volunteers were outfitted with a pressure sensing mat around their pelvis, and readings were taken with each binder in place.

Here are the additional factoids:

  • The tissue damage threshold was assumed to be 9.3 kPa sustained for more than 2-3 hours based on the 1994 paper cited below.
  • All binders exceeded the tissue damage threshold at the greater trochanters and sacrum while lying on a backboard. It was highest with the Pelvic Binder and lowest with the SAM sling.
  • Pressures over the trochanters decreased significantly after transfer to a hospital bed, but the Pelvic Binder pressures remained at the tissue damage level.
  • Pressures over the sacrum far exceeded the tissue damage pressure with all binders on a backboard and it remained at or above this level even after transfer to a bed. Once again, the Pelvic Binder pressures were higher. The other splints had similar pressures.

And finally, the price! Although your results may vary due to your buying power, the SAM sling is about $50-$70, the Pelvic Binder $140, and the T-POD $125.

Bottom line: The binder that performed the best (equivalent biomechanical testing, better tissue pressure profile) was the SAM sling. It also happens to be the least expensive, although it takes a little more elbow grease to apply. In my mind, that’s a winning combo. Plus, it’s narrow, which allows easy access to the abdomen and groins for procedures. But remember, whichever one you choose, get them off as soon as possible to avoid skin complications.

References:

  • Comparison of three different pelvic circumferential compression devices: a biomechanical cadaver study. JBJS 93:230-240, 2011.
  • Randomised clinical trial comparing pressure characteristics of pelvic circumferential compression devices in healthy volunteers. Injury 42:1020-1026, 2011.
  • Pressure sores. BMJ 309(6959):853-857, 1994.
Equipment

What’s The Best Pelvic Binder? Part 1

Leave a comment

Several products for compressing the fractured pelvis are available. They range from free and simple (a sheet), to a bit more complicated and expensive. How to decide which product to use? Today, I’ll discuss the four commonly used products. Tomorrow, I’ll look at the science.

First, let’s dispense with the sheet. Yes, it’s very cheap. But it’s not easy to use correctly, and more difficult to secure. Click here to see my post on its use.

There are three commercial products that are commonly used. First is the Pelvic Binder from the company of the same name (www.pelvicbinder.com). It consists of a relatively wide belt with a tensioning mechanism that attaches to the belt using velcro. One size fits all, so you may have to cut down the belt for smaller patients. Proper tension is gauged by being able to insert two fingers under the binder.

Next is the SAM Pelvic Sling from SAM Medical Products (http://www.sammedical.com). This device is a bit fancier, is slimmer, and the inside is more padded. It uses a belt mechanism to tighten and secure the sling. This mechanism automatically limits the amount of force applied to avoid problems with excessive compression. It comes in three sizes, and the standard size fits 98% of the population, they say.

Finally, there is the T-POD from Pyng Medical (http://www.pyng.com/products/t-podresponder). This one looks similar to the Pelvic Binder in terms of width and tensioning. It is also a cut to fit, one size fits all device. It has a pull tab that uses a pulley system to apply tension. Again, two fingers must be inserted to gauge proper tension.

So those are the choices. Tomorrow, I’ll go over some of the data and pricing so you can make intelligent choices about selecting the right device for you.

Grading

Grading A-P Force Pelvic Injury

Leave a comment

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.

General

What’s The Best Pelvic Binder? Part 2

Leave a comment

Yesterday, I detailed some pelvic binders commonly available
in the US.
Today, I’ll go through the (little) science there is regarding which are better
than others.

There are a number of factors to consider when choosing one
of these products. They are:

  • Does it work?
  • Does it hurt or cause skin damage?
  • Is it easy to use?
  • How much does it cost?

It’s difficult to determine how well binders work in the live,
clinical setting. But biomechanical studies can serve as a surrogate to try to answer
this question. One such cadaver study was carried out in the Netherlands a
few years ago. They created one of three different fracture types in pelvis
specimens. Special locator wires were placed initially so they could measure bone movement
before and after binder placement. All three of the previously discussed
commercial binders were used.

Here are the factoids:

  • In fracture patterns that were partially stable or unstable,
    all binders successfully closed the pelvic ring.
  • None of the binders caused adverse displacements of fracture
    fragments.
  • Pulling force to achieve complete reduction was lowest with
    the T-POD (40 Newtons) and highest with the SAM
    pelvic sling (120 Newtons).
    The SAM sling limits compression to 150 Newtons,
    which was more than adequate to close the pelvis.

So what about harm? A healthy volunteer study was used to
test each binder for tissue pressure levels. The 80 volunteers were outfitted
with a pressure sensing mat around their pelvis, and readings were taken with
each binder in place.

Here are the additional factoids:

  • The tissue damage threshold was assumed to be 9.3 kPa
    sustained for more than 2-3 hours based on the 1994 paper cited below.
  • All binders exceeded the tissue damage threshold at the
    greater trochanters and sacrum while lying on a backboard. It was highest with
    the Pelvic Binder and lowest with the SAM sling.
  • Pressures over the trochanters decreased significantly after
    transfer to a hospital bed, but the Pelvic Binder pressures remained at the
    tissue damage level.
  • Pressures over the sacrum far exceeded the tissue damage pressure
    with all binders on a backboard and it remained at or above this level even
    after transfer to a bed. Once again, the Pelvic Binder pressures were higher. The
    other splints had similar pressures.

And finally, the price! Although your results may vary due to
your buying power, the SAM sling is about $50-$70, the Pelvic Binder $140, and
the T-POD $125.

Bottom line: The binder that performed the best (equivalent
biomechanical testing, better tissue pressure profile) was the SAM sling. It also happens to be the least expensive, although it takes a little more elbow grease to apply. In my mind, that’s a winning combo.
Plus, it’s narrow, which allows easy access to the abdomen and groins for
procedures. But remember, whichever one you choose, get them off as soon as
possible to avoid skin complications.

What’s the best pelvic binder? Part 1

References:

  • Comparison of three different pelvic circumferential
    compression devices: a biomechanical cadaver study. JBJS 93:230-240, 2011.
  • Randomised clinical trial comparing pressure characteristics
    of pelvic circumferential compression devices in healthy volunteers. Injury 42:1020-1026,
    2011.
  • Pressure sores. BMJ 309(6959):853-857, 1994.