The Role of Routine Preoperative Magnetic Resonance Imaging in Idiopathic Scoliosis: A Ten Years Review

STUDY DESIGN: Prospective study. PURPOSE: To determine the role of routine preoperative magnetic resonance imaging (MRI) to detect the incidence and risk factors for intraspinal anomalies in patients with idiopathic scoliosis. OVERVIEW OF LITERATURE: The incidence and risk factors for intraspinal anomalies in patients with idiopathic scoliosis are controversial, and the indications for preoperative MRI in these patients vary among centers. METHODS: Information on patients with idiopathic scoliosis who were surgical candidates over 10 years (age at presentation, sex, magnitude and apex of major curve, intraspinal anomalies detected by MRI, and neurological examination results) were recorded, the patients were grouped according to the intraspinal anomaly, and the data were analyzed. RESULTS: Of the 271 patients with idiopathic scoliosis, 27 had neuroaxial abnormalities (9.9%). Of these 27 patients, 14 (52%) underwent a neurosurgical procedure. Significant differences were observed in the frequency of early disease onset and male sex (p<0.05) between the group of patients with neuroaxial abnormalities on preoperative MRI and those who did not have a cord anomaly. No difference was detected in the magnitude or direction of the curve. CONCLUSIONS: Neuroaxial abnormalities in patients with idiopathic scoliosis and a normal neurological examination were highly frequent (9.9%). Missing these abnormalities before surgery could inflict catastrophic postoperative complications. The incidence of neuroaxial abnormalities was higher in male patients and in those with early onset disease. Thus, MRI is essential for all patients with idiopathic scoliosis who require medical intervention.

prevalence of distal junctional kyphosis following posterior instrumentation and arthrodesis for adolescent idiopathic scoliosis

Distal junctional kyphosis [DJK] is a radiographic finding in patients that undergo spinal instrumentation and fusion, since there is an abrupt transition between fixed and mobile spinal segments.The true incidence of DJK is variable in literature and seems that has a multifactorial etiology. A consecutive series of 130 patients [mean age 15.6 years] with Adolescent Idiopathic Scoliosis who underwent posterior spinal fusion and instrumentation were evaluated by analyzing coronal and sagittal angulation and balance measurements from standing radiographs obtained pre-operatively, within 6 weeks post-operation, at two years postoperative and at the latest follow-up. There was 35 male and 95 female. The mean time of followup was 36 months. The incidence of DJK at latest follow-up was 6.9% [9 patients]. In DJK group, distal junctional angle from pre-operative of-12.5 lordosis [-30 to 0] reached to-5.5 [P=0.015] at 6 weeks postoperation and to-1.4 [-20 to 12] [P=0.000] at 2 years follow-up, with mean of 12.1 kyphotic change [10-20]. In non DJK group, distal junctional angle from pre-operative angle of-7.5 reached-8.1 at 2 years follow-up [P=0.43]. The mean age of DJK group at surgery was 17 years and for non-DJK group was 15.4 years [P=0.022]. Distal junctional kyphosis was less common in this study than previous reports and stabilized after two years. The magnitude of coronal cobb angles or multiplicity of coronal curves had no effect in developing DJK that may be prevented by incorporation of the first lordotic disc into the fusion construct