All posts by TheTraumaPro

Physical Exam And Thoracolumbar Spine Fractures

The physical exam is an important part of the initial evaluation of trauma patients. Sometimes it actually makes the diagnosis, but much of the time it focuses further studies like x-rays or lab tests. But we can also use it as a tool to avoid further imaging. For example, consider clinical clearance of the cervical spine. A negative exam in a reliable patient allows us to remove the cervical collar.

Can we apply the same thinking to the thoracic and lumbar spines? Many of us do. No pain or tenderness equates to no imaging or log-roll precautions.

The trauma group at LAC+USC looked at this one a few years ago. They studied every blunt trauma patient over a 6-month period, and first determined if they were “evaluable.” This meant not intoxicated, head injured (GCS<15), and no distracting injury (determined very subjectively). All underwent a standard exam of the TL spine by a resident or attending surgeon.

Here are the factoids:

  • 886 patients were enrolled, and 218 (25%) were not evaluable using the criteria above
  • 11% of the non-evaluable patients were found to have a TL spine fracture by CT, whereas only 8% of the evaluable group did
  • Of the evaluable patients, half (29) had no signs or symptoms of fracture
  • Of those 29 without signs or symptoms, two had a “clinically significant” fracture. Both were younger (20 and 59). One had a T7 compression and a transverse process fracture, the other a T9 compression fracture. Both were treated with a TLSO brace.
  • Of the 27 who could not be examined, 11 had “clinically significant” fractures; 8 were treated with TLSO and 6 with surgery (obviously some overlap there)

Bottom line: So physical exam of the thoracic and lumbar spine sucks, right? Not quite so fast! First, this is a small-ish study, but with enough patients to be intriguing. The biggest issue is that we don’t really know what is “clinically significant.” Treatment of stable fractures of the spine is controversial, and our friendly neighborhood neurosurgeons vary tremendously in how they do it. Ask five neurosurgeons and you’ll get six different answers.

Braces are expensive, and the optimal choice is not clear yet. At my hospital, we are treating select ones with a binder for comfort or a simple backpack brace. The fancier ones like the TLSO easily cost over $1000!

At this point, I recommend that you use a good blunt imaging practice guideline like the one below, coupled with a good physical exam. If the patient has sufficient mechanism to break something (which decreases with patient age), then image them. If they don’t, but have an abnormal exam, image them anyway. And we’ll wait for the next bigger/better study!

Related posts:

Reference: Clinical examination is insufficient to rule out thoracolumbar spine injuries. J Trauma 70(1):174-179, 2011.

Do We Need Cervical MRI Scans If The CT Is Negative?

The debate on how to clear the cervical spine just never ends. We have finally come to some degree of agreement that certain patients (awake, alert, not impaired or head injured, without distracting injury) can undergo clinical clearance alone.

But if those criteria are not met, what next? Universally, adults receive a CT scan of the cervical spine. In the majority of centers, this is coupled with a good clinical examination. And if both are negative, the collar can be removed.

But recent literature suggest that a good, high-quality cervical CT read by a skilled neuroradiologist may be good enough. This has been demonstrated in several papers involving patients who are comatose or other-wise unable to participate with a clinical exam.

Many centers and trauma professionals are still reluctant to remove the cervical collar without that clinical examination. A new study asked the question: would an MRI provide additional, significant information over and above the CT scan in those patients who could not be examined or had persistent neck pain?

A consortium of 8 Level I and II trauma centers in New England participated in this study coordinated by Yale. Blunt trauma patients who underwent MRI after negative cervical CT were considered for the study. On further review, if they received the scan because they could not be clinically evaluated, or if they had complaints of persistent neck pain, they were enrolled. CT scanners with at least 64-slice capabilities were required. There was no mention of the qualifications or special experience of the radiologists reading the images at each center.

Here are the factoids:

  • 767 patients were enrolled in this 30-month study. A total of 43% were for persistent neck pain, 44% for inability to examine, and 9% for both.
  • Nearly a quarter had an abnormal MRI scan:
    • 17% ligamentous injury
    • 4% soft tissue swelling
    • 1% disk injury
    • 1% dural hematoma
  • The collar was removed in most (88%) patients with a normal MRI, but in only 13% with ab-normal MRI
  • 11 patients underwent a surgical procedure and half had neurologic signs or symptoms. 10 of them had ligamentous injury, 1 had dural hematoma, and 1 had both

Bottom line: Looks almost compelling, right? One would think that we had better get an MRI on all of these patients! But read more closely, please. Yes, injuries were found. But did they really “require” an intervention? For some injuries, it’s a chip shot. A three column ligamentous injury equals stabilization in any textbook. But management of lesser injuries is less clear. And could some of these injuries have been recognized by a skilled neuroradiologist reading the CT image?

So what to do? There is not enough data for a universal protocol yet. Unfortunately, you will need to develop your own institutional policy based on the experience and opinions of your spine and neurosurgeons. They are the ones who will have to deal with the decision making during and after these studies. Until the definitive study comes along.

Reference: Cervical spine MRI in patients with negative CT: A prospective, multicenter study of the Research Consortium of New England Centers for Trauma (ReCONECT). J Trauma 82(2):263-269, 2017.

Long-Term Experience With Endovascular Aortic Repair For Trauma

For decades, the treatment of blunt injury to the thoracic aorta was open repair. The big debate at the time was use of cardiac bypass vs fast clamp and sew. But starting in 1997 with the introduction of thoracic endovascular aortic repair (TEVAR) of this injury, we have rapidly moved to the point where most traumatic aortic injuries are repaired using this technique.

A report that was written nearly a decade ago indicated a relatively high complication rate for the procedure. Graft complications were reported in 18% of patients, with 14% showing endoleaks. Stroke and left arm ischemia were also reported.

The diagram above shows insertion for management of an aneurysm, but the technique is similar for trauma. Blunt aortic injury occurs closer to the left subclavian artery and care must be taken to place the endograft closer to but not covering its orifice.

As the insertion systems and stents improved, short term events have been on the decline. Unfortunately, long term followup data has been hard to come by.

Until now. An article that is not yet in print reports 11 years of experience and followup with patient undergoing TEVAR at the ShockTrauma center in Baltimore.

Here are the factoids:

  • 88 patients underwent TEVAR during the study period, all from blunt trauma
  • Average ISS was 38, showing these patients were severely injured
  • Overall mortality was 7%, but none was due to the TEVAR procedure
  • TEVAR-related complication rate was 9% Endoleaks at the ends of the graft occurred in 4 patients, and all required repair. There were 4 other minor leaks that resolved on their own.
  • 26 had all or part of the left subclavian orifice covered at initial operation. None developed ischemia, although 2 had a prophylactic carotid-subclavian bypass before TEVAR.
  • The longest followup imaging occurred 8 years after the procedure. No long-term complications were noted.

Bottom line: TEVAR has essentially replaced open repair of the aorta, except in special cases. We continue to learn from our experience, and the complication rate is still falling. Other than endoleaks recognized in the postop period, most other complications rarely occur. Long term followup is poor, but in the patients who do return, there were no complications. But remember, this is an expected sampling bias. If the patient had major problems and/or died, they would just be lost to followup. We would never know.

Duplex Ultrasound For DVT: How Does It Work?

Admit it. You’re curious. You order this test for your trauma patients all the time but you’ve never seen it done. It’s simple and noninvasive, but it does require access to all areas to be evaluated. This means that extremities that are casted or splinted, or that have extensive dressings in place may be incompletely evaluated.

The study is called “duplex” because it makes use of two modalities: traditional ultrasound and Doppler ultrasound. Traditional ultrasound is used to view the compressibility of the veins of interest at a number of locations. Doppler measures the speed of blood flow under the probe, and can show areas of sluggish flow.

The following diagram shows the traditional ultrasound technique being used to compress the vein of interest (femoral, popliteal, etc.). Part A shows the probe gently resting over the vessels. Part B shows a fully compressible vein (normal), and Part C shoes partial compression due to the presence of thrombus.

The following diagram shows what the actual ultrasound study looks like. The right side is normal, but the left side shows a venous thrombosis.