Goal of the Study?
In this cross-sectional study from the International Journal of General Medicine1 the authors’ goal was to determine the diagnostic accuracy of grip strength in determining the presence of Degenerative Cervical Myelopathy.
Why are they doing this study?
If Degenerative Cervical Myelopathy (DCM) could be easily screened for in primary care, surgery at an appropriate time may prevent exacerbation of this disease and improve activities of daily living. Clinical tests and measures to rule out DCM include the Hoffman Test, Finger Escape Sign, Babinski Test, Lherminitte’s Sign and the 10 second Grip and Release Test. According to the authors, these tests are not in widespread use in many primary care settings. Grip strength is used in many orthopedic practices to assess DCM and evaluate sarcopenia, a condition characterized by a loss of skeletal muscle mass and strength in older adult patients. Grip strength tests are inexpensive, repeatable over time and easily administered by multiple levels of health practitioners, but according to the authors, the diagnostic accuracy of grip strength in DCM remains unknown.
What was done?
Over the years 2005 to 2017, a total of 368 patients aged 40 to 89 who underwent DCM surgery at the Orthopedic Department of the Fukushima Medical University in Japan had their grip strength measured just prior to surgery. After exclusions for a range of conditions, 249 DCM patients were compared to a similarly aged control group of 735 patients. Grip strength measurements in kilograms were taken. The minimum, maximum, average and laterality between left and right grip strength of the DCM and control groups by age categories and genders were plotted on ROC charts and the area under the ROC curves calculated. A Receiver Operating Characteristic (ROC) curve is a statistical classification tool used to determine the best cutoff value for a test. To create a ROC curve you simply plot the true positive rate and the false-positive rates of a test. Then the area under the curve determines the strength of the test. If the area under the ROC curve is 100% then you have a perfect test. If the area is 50% then the test has no ability to distinguish between true and false positives.
What did they find?
Diagnosis using the minimum right and left handgrip strength had the highest area under the ROC curve in all age categories and for both males and females, around 90%. As such it was the test that the authors used to calculate the various cutoff values to best determine the presence of DCM for each gender and age group. Generally, DCM causes bilateral muscle weakness, but in its early stages, it may affect one side more than the other, thus making minimum grip strength the best indicator test. The ROC cutoff values and urea under the curve for each gender and age group are replicated below.
|Gender||Age Group||Cut Off Value (kg)||Area Under Curve|
Why do these findings matter?
Minimum grip strength has significant diagnostic value for DCM. In primary care settings if a patient complains of numbness or difficulty using their hands minimum grip strength test could be easily administered. If their minimum grip strength is below the cut-off value for their gender and age group then the presence of DCM may be suspected.
At Dynamic Disc Designs, we craft dynamic cervical models to help professionals explain what the stages of degeneration looks like within a dynamic disc platform. Our cervical spinal stenosis model is an example of these 3d anatomical models.