Structural vs. Functional

Non-structural (functional) scoliosis 

A non-structural (functional) curve disappears when the patient is lying down or bending to the side. Temporary scoliosis is not unheard of and clinical experience has shown it is most commonly seen in the lumbar spine as a result of an injury to an intervertebral disc with secondary muscle spasm.

“Controlled clinical studies are consistent with the possibility that nonstructural and structural scolioses are functionally interchangeable at least in early stages of spinal deformity.”¹

Structural Scoliosis

Typically, structural curves are associated with a loss of spinal flexibility of the rotated vertebrae. Vertebrae become fixed and the rib cage can become rigid, especially when the thoracic vertebrae are involved. When x-rays are taken of a structural scoliosis, the curve is always present regardless of position. Cobb angle variation can occur over time.

X-rays for Scoliosis

Regarding x-ray, most physicians recommend a full scoliosis series. This is two views of the full spine: AP/Lateral scoliosis series – standing.  X-rays that do not depict the full spine do not allow for an accurate representation or assessment of a scoliosis.

 

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¹Hawes, Martha C., Ph.D., Scoliosis and the Human Spine: A critical review of clinical approaches to the treatment of Spinal deformity in the United States, ansd a proposal for change, Tuscon, Arizona: West Press, 2003.