HIgh Intensity Zone

HIgh Intensity Zone

HIgh Intensity Zone

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What is a High Intensity Zone?

In relationship to the spine,  it is a term that has been used on and off for the past 20 years.

Initially described by Drs’ April and Bogduk in 1992,  it is a  MRI finding  identified on a specific sequence called T2.  A High Intensity Zone (HIZ) is defined as an increased white signal in the margins of the disk annulus.   Dr.’s April and Bogduk  opined that it represented  an acute annular disruption, and thus a source of pain.  In the study (hyperlink above),  presence of this signal intensity was  associated with a painful grade 4 annular tear, and therefore, a reliable marker for back pain.

Armed with this information,  many physicians utilized this sign as an indication for potential spinal fusion surgery.  Unfortunately,  the increased surgical rates did not yield better clinical outcomes. In plain English,  this finding did not mean surgery would help.

In the December 2000 Article in Spine, by Dr. Carragee,  the author wanted to compare the results of discography in patients with and without the findings of these High Intensity Zones (HIZ). His study concluded the following:

“The presence of a high-intensity zone does not reliably indicate the presence of symptomatic internal disc disruption. Although higher in symptomatic patients, the prevalence of a high-intensity zone in asymptomatic individuals with degenerative disc disease (25%) is too high for meaningful clinical use. When injected during discography, the same percentage of asymptomatic and symptomatic discs with a high-intensity zone were shown to be painful.”

This study was awarded the 2000 Volvo Award for Clinical Studies.  And,  this study may have identified why the clinical results of surgical management of HIZ lesions was less than predicted.

Since these early studies,  there have been numerous studies on this topic.  Some studies compared the “acuteness” of these findings.  These studies suggest a HIZ lesion cannot be used to determine the recentness of the findings.  In other words,  HIZ cannot determine if the findings just developed, or was there for several years.

Other studies have even disputed the clinically significance of discography itself.

Not to be an alarmist,  but recent studies suggest the act of disography on a normal disk  (control level) will cause that disk to degenerate at a faster rate that if it had never have the study.

With all these controversies at hand,  a prudent clincian needs to determine if the information is relevant to the individual patient.  The clinician must also weigh the risks of the diagnostic procedure versus the benefit of the information.

In patients that are considering spine surgery,  the great unknown is whether the findings on the studies are the true cause of the pain or dysfunction.  That is because there is such a high prevalence of these findings in asymptomatic people.   The surgeon,  along with the patient, and yes,  the payors of the procedure ( it is not always the patient) must determine if the information from tests  is causing the condition of the patient.   Everyone must assess the risks,  benefits and potential for a positive outcome.

And,  unfortunately, these rational decisions  must be formulated with a patient is in alot of pain, with significant frustration, and fear of uncertainly. Sometimes,  the severity of the situation may sway the group to make a risky decision that may not be the best one.   In the end,  it will always come down to a calculated risk.  Better clinicians know when to take that risk, and for which circumstance.  Better clinicians weigh the information, both scientific and clinical, to make the best decision.

 

 

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Author and Contributor to www.Spine-Health.com – July, 2015

www.Spine-Health.com/author/john-h-shim-md-facs

Chief of Surgery, Mease Countryside and Mease Dunedin Hospitals, Safety Harbor and Dunedin, Florida. 2014-2016.

Orthopaedic Section Chief Mease Countryside Hospital; Safety Harbor, Florida Mease Dunedin Hospital; Dunedin, Florida.2008-2013

Board Member Morton Plant Mease Research Council

Co-Director of Mease Neuro-Ortho Spine Center Mease Dunedin Hospital; Dunedin, Florida.

One of “6 Spine Physicians Ranked #1 on Google” – December 2016

Top Ten Most Liked Spine Surgeons on the Internet – July 2016

2016 Spine Surgeons to Know list – January 2016

2014 Spine Specialists to know list – September 2014

One of Ten Leaders of Certified Spine Programs – December 2011

 

The Best Orthopedics in Tampa

The information provided on this website does not provide or should be considered medical advice. It is not a substitute for diagnosis or treatment of any condition. The information provided is for informational purposes only. You should not rely solely on the information provided on this website in making a decision to pursue a specific treatment or advice. You should consult directly with a professional healthcare provider.

As a condition of using the information on this website, ShimSpine and its physicians are not responsible for any advice, diagnosis, treatment or outcome you may obtain.

ShimSpine.com is completely self-funded. No outside funds are accepted or used. This website does not utilize paid advertising as a source of revenue.
Outpatient Spine Surgery Considerations. www.Spine-Health.com. January 2016.

What is Spinal Stenosis? www.Spine-Health.com. October 2015.

Surgeon insights on the Changing Landscape of Orthopedic Care. OrthopedicToday. June 2014

Chapter 33: Interspinous Spacers. Shim JH, Mazza JS, Kim DH Published in Minimally Invasive Percutaneous Spinal Techniques. Elsevier Health Sciences, Philadelphia, Pennsylvania. (Published 2011)

Chapter 35: Minimally Invasive Percutaneous Lumbar Fusion Technique.Shim JH, Mazza JS, Kim DH Published in Minimally Invasive Percutaneous Spinal Techniques. Elsevier Health Sciences, Philadelphia, Pennsylvania. (Published 2011)

March 2010 Minimally Invasive Transforaminal Lumbar Interbody Fusion American Academy of Orthopaedic Surgeons Annual Meeting New Orleans, Louisiana February 2010

February 2010 A Review of Dynamic Stabilization in the Lumbar Spine Selby Spine Symposium; Park City, Utah

November 2009 Lumbar Spinal Stenosis Community Based Lecture; Tampa, Florida

September 2009 Instructor/Proctor Minimally Invasive Lumbar Cadaver Lab; Tampa, Florida

February 2009 New Spinal Technology: Cervical Disc Replacement and Interspinous Spacers. Selby Spine Symposium; Park City, Utah

February 2008 The Degenerative Spine: The Role of Dynamic Lumbar Stablization and Interspinous Spacers Selby Spine Symposium; Park City, Utah

October 2008 Emerging Technology and Techniques in Spinal Surgery Orthopaedics in the 21st Century Symposium; Morton Plant Mease Healthcare; Largo, Florida

September 2007 Emerging Technology in Spinal Surgery Orthopaedics in the 21st Century Symposium; Morton Plant Mease Healthcare; Largo, Florida

October 2006 Emerging Technology and Techniques in Spinal Surgery Orthopaedics in the 21st Century Symposium; Morton Plant Mease Healthcare; Largo, Florida

May 2005 The Role of Kyphoplasty in the Treatment of Vertebral Compression Fractures Mease Neurosciences Symposium; Clearwater, Florida
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