Radiation-Free Surface Topography Is Highly Correlated With X-Ray Outcomes and Self-Image in Adolescent Idiopathic Scoliosis

Peer Reviewed

Improvements in body shape assessed using radiation-free surface topography following scoliosis surgery were highly correlated with x-ray outcomes and self-image in adolescent idiopathic scoliosis, according to findings from a prospective observational study presented at the American Academy of Orthopaedic Surgeons 2018 Annual Meeting held March 6-10 in New Orleans, Louisiana.

“Use of this technology will provide [spine surgeons] with information that can be used to counsel patients and their families about the improvements in their body shape that can be expected with surgery,” explained lead author Baron S. Lonner, MD, Professor of Orthopaedics at the Icahn School of Medicine at Mount Sinai, New York, NY. “Surface topography also can be used to modify corrective strategies as needed to improve body shape and by extension, self-image of the patient,” he added.

“I believe further study will show this zero-radiation tool to be very valuable in screening and observing patients with mild scoliosis over time,” said Dr. Lonner, who is also President of the Surface Topography Study Group.

Body Image Is a Big Issue for Adolescents With Scoliosis

“For adolescents with spinal curvatures that require surgical treatment, body image and self-esteem are big issues, as they are for all adolescents going through developmental stages,” Dr. Lonner told SpineUniverse. “Scoliosis has an impact on body shape, which is seen by the affected individual when looking in the mirror as well as by their peers and others around them. This can lead to self-esteem and body image disturbance issues.”

“We set out to explore the body shape distortions that occur with scoliosis, that are not depicted by x-rays standardly used to assess curvatures of the spine, and the improvements in parameters of body shape that occur with corrective surgery,” Dr. Lonner said. “We can assess body shape directly through surface topography imaging that is light-based and, thus, does not involve x-ray exposure. This technology (Diers Formetric) uses the same scientific methodology that is used to create modern topographical maps through satellite imagery.”

The study included 23 consecutive patients with adolescent idiopathic scoliosis (19 females; median age, 15 years) who underwent posterior spinal fusion (n=17), anterior scoliosis correction (n=3), or a combination of posterior-anterior approaches (n=3). X-rays and posterior surface topography were taken before and after surgery. The researchers assessed the association of surface topography improvements with surgical correction.

Improvements in scoliosis angle, T2-T12 kyphosis, surface rotation, sagittal imbalance, and coronal imbalance assessed using surface topography were significantly correlated with improvements assess using x-ray (Table and Figures A, B). In addition, waist asymmetry measured using surface topography was significantly correlated with the following post-operative measures: satisfaction (P=0.0143), self-image (P=0.0333), total post-operative domains (P=0.0298), and improvement in pain scores (P=0.0414). Furthermore, sagittal balance was significantly correlated with improved function (P=0.0237).

Table. Correlation Between Surface Tomography and X-ray MeasurementsTable. Correlation Between Surface Tomography and X-ray Measurements

Pre-operative and post-operative images taken using surface tomography in a patient with adolescent idiopathic scoliosisFigure A. Pre-operative and post-operative images taken using surface tomography in a patient with adolescent idiopathic scoliosis. Images courtesy of Baron S. Lonner, MD

Pre-operative and post-operative images taken using x-ray in a patient with adolescent idiopathic scoliosisFigure B. Pre-operative and post-operative images taken using x-ray in a patient with adolescent idiopathic scoliosis. Images courtesy of Baron S. Lonner, MD.

Is Surface Topography as Reliable as X-Ray?

Previous research by Dr. Lonner and colleagues found that 3D spinal measurements of thoracic and lumbar curves made using surface topography were reliable and highly correlated with x-ray parameters.1

“Surface topography could be used post-operatively as a primary measure of the patient’s outcome once the patient has reached full recovery by 6 months or so, and x-rays reveal implants to be in desirable position,” Dr. Lonner said, “Surface topography can then be used at various routine follow-up time points with x-rays only being used in the case of new onset of symptoms. The use of surface topography in lieu of x-ray will require further study.”

Is Use of Surface Topography Practical?

“My team and I routinely use surface topography before surgery and at one time point after surgery to document the change in the patient’s body shape,” Dr. Lonner told SpineUniverse.

“We use the Diers Formetric system, which has a relatively limited footprint,” Dr. Lonner explained. “The equipment is approximately 6 feet high and 1.5 feet square, and a distance of 6 feet from the patient is required to perform the scan. Most clinical settings permit the space to make this test routinely available.”

Future Research

“We are in the process of assessing the distortions of body shape in the frontal view (what the patient directly sees in the mirror) and the body shape improvements of those asymmetries,” Dr. Lonner concluded. “We have collected information on over 50 patients already, and intend on collecting this data on all patients going forward.”

Dr. Lonner has no relevant disclosures.

Updated on: 03/12/19
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Effective Value-Based Initiatives for Complex Spine Surgery
Baron S. Lonner, MD
Director, Scoliosis Associates
Professor of Orthopaedic Surgery
Icahn School of Medicine at Mount Sinai
New York, NY

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