Back Braces: Are They Really Needed?

October 3, 2023 The Trauma Pro Leave a comment

Back braces have always confused me. There are so many types: TLSO, LSO, backpack, extension, and even the lowly abdominal binder can function as a brace. And I have never been able to predict which brace my spine colleagues accurately would prescribe for a specific condition or injury.

Many vertebral fractures can be treated non-operatively. And it seems intuitive that there would be some benefit from splinting the spine to limit the range of motion to enhance healing. So I would like to concentrate on some papers that examined the use of back braces on patients who underwent pedicle screw fixation of their thoracic and/or lumbar spine fractures.

I found two systematic reviews and a ten-year prospective clinical trial. First, the reviews.

The first was published in 2016 and examined papers comparing postop bracing vs. no postop bracing. It looked at loss of deformity correction, return to work, functional improvement, instrumentation failure rate, pseudoarthrosis, and postop complications. A total of 76 studies were included.

The average wear time for the braces was just over three months. There was no difference in pain, return to work, functional outcome, or instrumentation failure. Interestingly, there was a significant increase in the number of patients who lost kyphotic reduction from the procedure and a significant increase in the number of complications. Unfortunately, the authors did not break out specific complications other than wound infections. Although these were higher in the braced group (2.8% vs. 1.8%), this difference was not significant. One real positive for the brace: the number of pseudoarthroses was significantly less (2.4% vs. 6%).

The next review looked at postoperative bracing from a cost-effectiveness standpoint. It considered adverse events such as infections and hardware failure and examined a total of 1957 patients across 48 papers. Non-braced patients were somewhat older. Braced patients had significantly fewer reoperations for non-union or hardware failure (1.3% vs. 1.8%). There was no difference in wound dehiscence or infection. Overall, there was no cost benefit to applying a back brace in these patients after pedicle screw fixation.

The last paper was a prospective clinical trial that enrolled 144 patients randomized to brace or no brace after their surgical procedure. They underwent multiple postop evaluations to monitor quality of life, success of the fusion, pain, mobility, and return to previous activities.

Here are the factoids:

Mean age was only 34 years, and only fractures of T11 to L5 were included
Two-thirds of the injuries were due to falls, and most of the remaining ones were from car crashes
Three-quarters were burst fractures, and the remaining were wedge or fracture-dislocation injuries
There were no differences in early mobilization, residual pain, return to previous activities, quality of life, or success of the fusion after one year

The authors concluded that the use (or non-use) of a TLSO brace after pedicle screw fixation of these fractures does not affect treatment. They state that TLSO braces are not required in the postop period for these patients.

Bottom line: Interesting, yet slightly confusing. The systematic reviews show a significant increase in pseudoarthrosis in patients without braces. This was not seen in the prospective study. The discrepancy could be due to the quality of the papers included in the reviews or insufficient power in the prospective study. So it may be too early to fully know the difference. But it appears to be so small that the question of whether a brace is really necessary needs to be asked.

Most braces are expensive and uncomfortable. I have seen several patients in follow-up who basically stopped wearing their brace as soon as they were out of the hospital. And anecdotally, they did fine.

A large, multicenter study in progress in the Netherlands will analyze the same factors listed above. Unfortunately, the listing on clinicaltrials.gov indicates they are only recruiting 45 patients, which may not add much to what is already known due to low statistical power.

In the meantime, consider discussing with your spine surgeons reviewing the current literature on back bracing. It may be possible to reduce the number of eligible patients who take their brace home and use it as a chew toy for the dog.

References:

Bracing After Surgical Stabilization of Thoracolumbar Fractures: A Systematic Review of Evidence, Indications, and Practices. World Neurosurg 93:221-228, 2016.
Post-operative bracing after pedicle screw fixation for thoracolumbar burst fractures: A cost-effectiveness study. J Clin Neurosci 45:33-39, 2017.
Evaluation of postoperative bracing on unstable traumatic lumbar fractures after pedicle screw fixation. Int J Burns Trauma 12(4):168-174, 2022.
Is postoperative bracing after pedicle screw fixation of spine fractures necessary? Study protocol of the ORNOT study: a randomised controlled multicentre trial. NCT03097081. Listed in 2017, to be completed Nov 2026.

Complications

How Much Fetal Radiation Exposure In Imaging Studies?

September 26, 2023 The Trauma Pro Leave a comment

I periodically publish a chart that shows how much radiation exposure our patients get from various trauma imaging studies. For reference, here it is:

Test	Dose (mSv)	Equivalent background radiation
Chest x-ray	0.1	10 days
Pelvis x-ray	0.1	10 days
CT head	2	8 months
CT cervical spine	3	1 year
Plain c-spine	0.2	3 weeks
CT chest	7	2 years
CT abdomen/pelvis	10	3 years
CT T&L spine	7	2 years
Plain T&L spine	3	1 year
Millimeter wave scanner (that hands in the air TSA thing at the airport)	0.0001	15 minutes
Scatter from a chest x-ray in trauma bay when standing one meter from the patient	0.0002	45 minutes
Scatter from a chest x-ray in trauma bay when standing three meters from the patient	0.000022	6 minutes

One of the issues that trauma professionals gnash our teeth about is how much radiation the baby gets when we perform these studies on pregnant women. Well, here is just what you need. Another chart! In order to avoid confusion, I will list effective doses to the fetus in milligrays (mGy), which is how much radiation is deposited in a substance. This is a little confusing, since doses are frequently listed in millisieverts which takes the specific organ and type of radiation into effect. In general, these two units are very similar for x-rays.

A useful rule of thumb is that if the fetal dose is less than 50 mGy during any trimester, the risk of an abortion or fetal malformation is about the same as from other risks to the pregnancy. The American College of Radiology notes that exposures less than 100 mGy are “probably too subtle to be clinically detectable.”

To help in your clinical decision making, I’ve added some extra information to the table regarding fetal exposure:

Test	Adult Dose (mSv)	Fetal Dose (mGy)
Chest x-ray	0.1	negligible
Pelvis x-ray	0.1	negligible
CT head	2	<1
CT head and C-spine	4	10
CT chest	7	<1
CT abdomen/pelvis	10	25
Pan Scan (CTA chest, abdomen, and pelvis)	up to 68	up to 56
CT pulmonary angiogram	up to 40	<1

Bottom line: We still have to think hard about how we image pregnant patients! There are some alternatives available to us, including the good old physical exam, conventional x-rays, and ultrasound. MRI is possible, but is a pain in the ass for many reasons.

CT of the head and cervical spine are fine for both mother and baby, and non-contrast imaging of the torso is within accepted limits of fetal exposure. However, the whole point of the torso scan in CT is to identify critical injuries that may lead to exsanguination like solid organ and aortic injuries. In general, those scans should always be ordered with contrast.

If clinical suspicion is high, it may be necessary to order these higher-dose studies anyway. If the mother has an unrecognized and potentially fatal injury, the baby will not survive either. There are many, many permutations of injuries and diagnostics. These cases will put your clinical judgment to the test, for sure!

References:

Imaging Pregnant and Lactating patients. RadioGraphics 35:6, 1751-1765, 2015.
Imaging of the pregnant trauma patient. RadioGraphics 34:3, 748-763,2014.
Fetal doses from radio logical examinations. Br J Radiol;72(860): 773–780, 1999.

Abstracts, Resuscitation

Best Of AAST #8: Whole Blood At The Scene Of Injury

September 21, 2023 The Trauma Pro Leave a comment

Here’s another abstract with a promising title that suffers from low subject numbers. Whole blood is the new darling of trauma resuscitation. Assembling a unit of whole blood from the components it was broken down into produces an inferior product from the standpoint of resuscitation.

It makes sense from a coagulation standpoint, but there are a few pesky issues that need to be considered, such as antibody titers. So I understand the enthusiasm to get some papers out there that describe the value of it.

A group in the Czech Republic performed a prospective study that assigned patients to receive scene resuscitation with either one unit of packed cells plus one unit of plasma, or two units of low titer group O whole blood. They had a host of primary outcomes, including feasibility, 24-hour and 30-day mortality, 24-hour blood use and fluid balance, and initial INR. They compared the two groups to matched cohort controls from a trauma registry. The study was performed over a three year period.

Here are the factoids:

Three groups of about 50 patients each were enrolled
There was no difference in 24-hour mortality, but the authors claimed that the 30-day mortality was “better.” However, the numbers were not statistically significant.
They found a statistically significant decrease in 24-hour transfusion volume of about 500cc, which is not clinically significant
Similarly, there was an increase in fluid balance of about 2L
They also found a “significant” decrease in INR from 1.17 to 1.10, which is also not clinically significant
There were no transfusion reactions

The authors concluded that whole blood was safe to give at the scene and that there were improvements in the measured parameters.

Bottom line: Sorry, but the abstract does not really support the title. This study is woefully small, and confusing to read. The purpose of the registry control cohort was not clear, and the extra results further muddied the picture. The statistical analyses were not included, and I am skeptical that they fully support the conclusions. There is just no statistical power to achieve significance with the number of subjects in this study. And many of the differences, even if they were statistically significant, were not clinically significant.

I don’t want to be a downer here. I do believe that whole blood is a good thing. Unfortunately, the whole blood in this study could have been better used doing a much bigger, multicenter study to truly show us the benefits.

Reference: Whole blood on the scene of injury improves clinical outcome of the bleeding trauma patient. AAST 2023, Plenary paper #28.

Abstracts, Resuscitation

Best Of AAST #7: How Do You Like Your Platelets – Warm Or Cold?

September 20, 2023 The Trauma Pro Leave a comment

Until the last few years, massive transfusion in trauma consisted of component therapy, an admixture of packed red cells, plasma, and platelets. Whole blood transfusion is making inroads again, but it is used in a minority of centers.

Of the three components, platelets have classically required different handling than the others. They are generally kept at room temperature, while the red cells and plasma are kept very cold to preserve their shelf life. A few centers have toyed with the use of cold platelets, but there have been concerns about their ability to clot and their useful life after transfusion.

Researchers from the US Army performed a retrospective registry study on a sample of military casualties over four years. They identified soldiers who received either room-temperature or cold-stored platelets. The primary outcome was mortality, and secondary outcomes included the need for surgery, fluid and blood infusions, and the use of a massive transfusion protocol.

Here are the factoids:

A total of 300 patients were identified, nearly equally split between room temp platelets and cold-stored
Demographics of the two groups were similar, but the ISS was somewhat higher in the cold-stored platelet group
Significantly fewer cold-stored platelet patients underwent surgery (13% vs. 24%)
Survival was the same at 87-88%
Blood and product administration was significantly higher in the cold-stored group, as was the use of the MTP (54% vs. 34%)

The authors concluded that the use of cold-stored platelets were not inferior to room temperature platelets.

Bottom line: Huh?? Yes, survival was the same despite a higher ISS in the cold platelet group. But they required more blood and needed massive transfusion significantly more often.

I see two major issues with this study. The most important is that it is a non-inferiority study. To believe that both arms are equal, a power analysis is required. The sample size here is too small to achieve significance unless differences are extreme, like the transfusion and MTP numbers.

The second problem is that this is an association study. Attempting to show that the type of platelets used is a major determinant of survival, need for surgery, or blood product use is shortsighted. There are a myriad of other factors that have more of an impact.

Far more subjects need to be studied, and a retrospective study with limited data points is not enough. I’m surprised that a military registry could only come up with 75 patients a year to analyze. These low numbers and the nature of this particular registry could inject significant bias as well.

Stay with the room temp platelets for now, and wait for a well-powered prospective analysis before changing your MTP.

Reference: An analysis of the use of cold-stored platelets in combat trauma. AAST 2023 Plenary paper #29.

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