Standard assessments of cervical spine instability are unreliable-computer QMA better

[herniated C6-7]

My doctors have split on whether I have spinal instability at C5-6. This led me to do a search of the medical literature at the Pubmed website PubMed home. I found the article cited below.

The article reports that in viewing flexion-extension Xrays for 75 cervical spine patients the usual way there was general agreement among 7 doctors only in 12 of the 75 cases, or 16% of the time. But when computer-assisted technology for quantitative motion analysis was used, there was unanimity among the 7 doctors in 57 of the 75 cases--an increase to 70% of the time. The increase in reliability is partly due to the imposition of a standard definition of stability/instability, partly due to the ability to hold points fixed at the ends of vertebra while superimposing another viewpoint for measurement of translation or rotation.

The computer assisted QMA technology is not yet used in everyday practice but widely used in clinical trials and cited in some 1300 medical journal articles. That means some doctors are familiar with it. You may be able to get a list of doctors familiar with the technology in your area by contacting the company that sells it: Medical Metrics in Houston, Texas. I have sent my imaging to one of the co-authors of the article cited below, Dr. Charles Reitman, for an opinion based on use of the technology.

Spine J. 2007 Nov-Dec;7(6):654-8. Epub 2007 Jan 12.
Observer agreement in assessing flexion-extension X-rays of the cervical spine, with and without the use of quantitative measurements of intervertebral motion.
Taylor M, Hipp JA, Gertzbein SD, Gopinath S, Reitman CA.
Department of Orthopedic Surgery, Baylor College of Medicine, Houston, TX 77030, USA

METHODS: Seventy-five flexion-extension X-rays of the cervical spine, obtained from several clinical practices, were assessed by seven practicing physicians who routinely assess these X-rays. Observers assessed the studies using the methods they routinely use, and then reassessed the studies, at least a month later, using validated computer-assisted methods. Agreement among clinicians with and without computer-assisted technology was assessed using kappa statistics.

RESULTS: Agreement was poor (kappa=0.17) with methods routinely used in clinical practice. Computer-assisted analysis improved interobserver agreement (kappa=0.77). With computer-assisted methods, disagreements involved cases with severe degeneration or static misalignment where motion was within normal limits, or in fusion cases where there was between 1 and 1.5 degrees of motion at the fusion site.

[Harrison]

Thx for sharing this interesting article...