Is "routine" magnetic resonance imaging necessary in adolescent idiopathic scoliosis? A retrospective analysis in New Zealand.

Abstract

Study design: Retrospective case series.

Purpose: To determine the prevalence of neural axis abnormalities (NAA) in patients with adolescent idiopathic scoliosis (AIS) undergoing deformity corrective surgery and evaluate factors that may predict the presence of underlying NAA in these patients.

Overview of literature: There is no clear consensus regarding the use of magnetic resonance imaging (MRI) to screen for potential NAA in patients with AIS. Various clinical and radiographic risk factors predicting underlying NAA have been suggested, but these remain controversial.

Methods: This study included 282 patients with presumed AIS who underwent preoperative MRI to exclude NAA between 2010 and 2020 in multiple centers. Spinopelvic parameters, including Cobb angle, thoracic kyphosis, lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence, were measured on preoperative and postoperative radiographs. Additional clinical data were gathered on curve characteristics, symptomatic back pain, and abnormal preoperative neurological examinations.

Results: The median age was 14 years (range, 11-18 years). The cohort consisted of 49 males (17%), 217 patients (77%) of European ethnicity, 30 (10.6%) Māori, and 7 (2.5%) Pacific Islanders. Twenty-one patients (7.4%) had NAA, of which five required neurosurgical intervention. Among the NAA group, four were diagnosed with Chiari malformations, seven with syringomyelia, and four with both. The presence of NAA did not affect curve reduction with surgery. No significant association was found between NAA and any investigated variable.

Conclusions: Routine preoperative MRI is justifiable, as 7.4% of the cohort had NAA, with five patients requiring neurosurgical intervention, thereby altering operative management.