www.clear-institute.org Jan/Feb 2009

CLEAR Institute Monthly Newsletter



Chiropractic Leadership, Educational Advancement, & Research

Jan/Feb 2009 Newsletter Content

An Overview of Cobb Angle, by Dr. Will Kalla
Test Your Cobb Angle IQ
CLEAR Clinic to Open in the UK; Doctors Needed!

Upcoming Seminars in 2009
Updated Exercise Protocols





An Overview of Cobb Angle
By Dr. Will Kalla, Precision Spine Center, Singapore

The term "Cobb Angle" is used worldwide to measure and quantify the magnitude of spinal deformities, especially in the case of scoliosis. It is used as the standard measurement to quantify and track the progression of Idiopathic Scoliosis. Cobb Angle was first expressed in 1948, by Dr. John R Cobb, where he outlined "how to measure the angle of the curve." Hence, the term "Cobb Angle" came about, bearing his name.
When the Adam’s Test that is used to screen for scoliosis proves to be positive, an X-ray will be performed on the patient and the Cobb angle measured on the X-ray according to the method prescribed below:
First, locate both the end vertebrae of the curve (the vertebrae with the most tilted endplates). Then, at the top of the curve, draw a parallel line to the highest vertebral endplate, and at the bottom, a parallel line to the lower vertebral endplate. The angle between these two lines (or lines drawn perpendicular to them) is the Cobb Angle for that curve.

To track the progression or improvement of scoliosis treatment on the curve, pre and post x-rays have to be taken so that the respective Cobb angles can be measured and compared. It must be stressed that the same two vertebral segments in both pre and post x-rays are used for measurements.

The Cobb Angle however, is not without a downside. Studies examining the reliability and accuracy of the Cobb Angle measurement have been conducted, and concluded that Cobb Angles can have a margin of error of between 6°-7° (refer to the table below summarizing findings) This is basically a result of trying to determine the spinal curvature of a three-dimensional structure using a two-dimensional basis for measurement. Nevertheless, despite its shortcomings, the Cobb Angle still remains the most popular measurement to express the magnitude of a scoliosis curve, as it is the simplest concept for doctors to articulate, and patients to relate to.


Additional References:


Shea KG, Stevens PM, Nelson M, Smith JT, Masters KS, Yandow S.

A comparison of manual versus computer-assisted radiographic measurement.

Intraobserver measurement variability for Cobb angles.

Spine. 1998 Mar 1;23(5):551-5.



Sevastikoglou JA, Bergquist E.

Evaluation of the reliability of radiological methods for registration of scoliosis.

Acta Orthop Scand. 1969;40(5):608-13.



Morrissy RT, Goldsmith GS, Hall EC, Kehl D, Cowie GH.

Measurement of the Cobb angle on radiographs of patients who have scoliosis.

Evaluation of intrinsic error.

J Bone Joint Surg Am. 1990 Mar;72(3):320-7.



Gross C, Gross M, Kuschner S.

Error analysis of scoliosis curvature measurement.

Bull Hosp Jt Dis Orthop Inst. 1983 Fall;43(2):171-7.



Beekman CE, Hall V.

Variability of scoliosis measurement from spinal roentgenograms.

Phys Ther. 1979 Jun;59(6):764-5.



Oda M, Rauh S, Gregory PB, Silverman FN, Bleck EE.

The significance of roentgenographic measurement in scoliosis.

J Pediatr Orthop. 1982 Oct;2(4):378-82.



Gstoettner M, Sekyra K, Walochnik N, Winter P, Wachter R, Bach CM.

Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools.

Eur Spine J. 2007 Oct;16(10):1587-92.






Test Your Cobb Angle IQ


"[Cobb angle] is an objective measure and is generally used to make decisions about the progression of a curve, as well as the need [for] and success of treatment." (Eur Spine J, 2007 Oct;16(10):1587-92)

For both people living with scoliosis and healthcare professionals working with it, everything revolves around the Cobb angle. After the diagnosis, x-rays are taken regularly to measure it. Once it hits 25, bracing begins; at 45, surgery is traditionally recommended. All forms of scoliosis treatment are judged primarily by their ability to reduce this important number.



To advance education regarding Cobb angle, CLEAR Institute has created a simple document which tests your ability to measure Cobb angle. It's designed for everyone; both doctors and laypeople are encouraged to download this short paper and test your Cobb angle IQ.

On the first page, there are two standard scoliosis x-rays, followed by a step-by-step description of how to analyze them. All you need is a protractor and a pencil or pen. After you have made the measurements, you are invited to share your results with CLEAR Institute, and everyone's measurements will be compiled & posted on our website. If there is enough interest in the topic of Cobb angle, CLEAR Institute has the capability of hosting a free animated, online program which will allow you to upload digital x-rays and either measure them yourself or have them measured by a CLEAR-certified doctor.

The document can be accessed & downloaded by clicking here:


http://drop.io/CobbAIQ

Whether or not you take the time to test your Cobb angle IQ, whenever the topic of Cobb angle comes up, please keep this statement from the aforementioned European Spine Journal in mind:

"One pitfall in angle measurement implies the Cobb angle itself. Until we develop a proper tri-dimensional measuring system, no matter how good the antero-posterior and lateral imaging results are, it is still only a two-dimensional picture. For the Cobb angle measurement the definition of end plate vertebrae introduces the main source of error. Digital radiography does not improve the measurement accuracy."


CLEAR Institute requires that our certified doctors measure Cobb angles on all of their patients, and detailed information about Cobb Angle is included in our scoliosis seminar series. However, the clinical decisions pertaining to what treatment each individual person with scoliosis will receive - such as what specific chiropractic adjustments are delivered, which rehabilitation exercises are prescribed, and so on - are not based upon this measurement, but rather on more precise analysis of several x-rays that are taken under standardized conditions.

Understanding the spine biomechanically, how it moves & functions in a gravitational environment, requires that we also examine what is happening above and below the Cobb angle. The spine is one dynamic unit, and does not function in isolation. Cobb angle is only a symptom of scoliosis, and by focusing purely upon the symptoms of any disease, the cause is neglected.






CLEAR Clinic to Open in the UK; Doctors of Chiropractic Needed!



CLEAR Institute has had an excellent response from the international community to our research & results, and now have quite a number of patients who fly to the USA from other countries to receive this treatment. One of these patients was so impressed with the improvements her daughter has made that she wants to invest in the first European CLEAR registered clinic, to be set up in the UK! She is looking for dedicated healthcare professionals who would be willing to pioneer this treatment in Europe and to help to make this the "gold standard" treatment for scoliosis patients. If you are receiving this newsletter then you are already interested in scoliosis and how we at CLEAR are making dramatic improvements to the quality of life of many people of all ages. If you are experienced in the chiropractic field & are based in the UK, or are willing to be based there and are interested in a future with this exciting new venture, then please contact us at care@clear-institute.org. The clinic is fully-equipped with all necessary CLEAR Scoliosis Equipment, and training & certification will be conducted on-site in the UK by a member of the CLEAR Board of Advisors.



Upcoming Scoliosis Seminar Opportunities

Parts 1 & 2 of the Scoliosis Correction Seminar are now available online! CE credits may be available in your state. Please contact care@clear-institute.org for more details.


Parker College of Chiropractic
Dallas, TX


Spring 2009 Series:
March 21-22, 2009 - Part I
April 4-5, 2009 - Part II
May 2, 2009 - Part III Workshop

Fall 2009 Series
October 10-11, 2009 - Part I
November 14-15, 2009 - Part II
December 5, 2009 - Part III Workshop

To register, please visit http://www.clear-institute.org/Resources/Seminars/tabid/240/Default.aspx, or call the Postgraduate Department of Parker College of Chiropractic at 1-800-GETMYDC.




Update to the Spinal Rehabilitation Exercise Protocols

With the advanced technology of Motion X-ray Imaging, CLEAR Institute has developed a new method of isolating & rehabilitating important muscles in the low back that demonstrates better structural corrections than the old Low Back Ball exercise.

If you have been treated by a CLEAR-certified doctor in the past and were prescribed this exercise as part of your home spinal rehabilitation program, please contact your doctor to receive important updates about the exercise protocols.


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