Preoperative and Postoperative Imaging in Idiopathic Scoliosis: What the Surgeon Wants to Know

Abstract

The term idiopathic scoliosis covers a broad spectrum of spinal deformities in the pediatric population without an underlying congenital anomaly of the spine. Depending on the age of presentation, it has both characteristic clinical and imaging features and a different prognosis. The radiologist should provide the surgeon with critical information to assess the degree of deformity and eventually plan surgery. Thoracic deformities and lung volume must also be part of the preoperative assessment. Imaging has a critical role in postsurgical follow-up and in surgical complications. This review highlights the importance of common terminology and measurement methods to avoid incongruences. The different imaging modalities are discussed with their indications and limitations. We pay special attention to imaging modalities that can help the surgeon assess skeletal maturation reliably and thus predict the prognosis of scoliosis. Radiation protection and the risk of cumulative radiation exposure in these patients is emphasized.

The Adolescent Spine

“…Normal thoracic kyphosis is between 21 and 42 degrees, and normal lumbar lordosis is between 31 and 50 degrees. 7 These values do not change with age, sex, height, or BMI. 50…”

“…Hence imaging plays a key role in unraveling conditions that can lead to spinal deformity including congenital spinal anomalies, posttraumatic conditions, myopathies, metabolic disorders, and neoplasms. 7…”

“…The position of the curve is determined by the vertebra that deviates most from the center line and with the highest degree of rotation. 7…”

“…It is the angle formed by the intersection of a line drawn along the center (midpoint) of the head and neck of each rib and a vertical line drawn perpendicular to the upper or lower end plates of the vertebra. 7 The RVA is usually smaller on the convex side of the curve. The RVA predicts the brace treatment outcome in Risser grade 0 and premenarchal girls with AIS.…”

“…The position of the curve is determined by the vertebra that deviates most from the center line and with the highest degree of rotation. 7 The Cobb angle is the reference method for assessing scoliosis. It is obtained by intersecting a line parallel to the upper end plate of the most tilted cephalad vertebra with a line parallel to the lower end plate of the most tilted caudad vertebra.…”