Magnetic resonance imaging abnormalities of neural axis in Lenke type 1 idiopathic scoliosis

Study Design. Patients with Lenke type 1 single thoracic idiopathic scoliosis were included in this prospective study. All patients had preoperative magnetic resonance imaging (MRI). Objective. To examine the frequency of neural axis abnormalities and the need for preoperative MRI in this group of patients. Summary of Background Data. Because of the increasing use of MRI, neural axis abnormalities have been reported in association with certain clinical and radiologic findings in idiopathic scoliosis cases. Methods. A total of 104 patients (49 juvenile onset and 55 adolescent onset), older than 10 years, were included in the study. The association of neural axis abnormalities with pes cavus, abnormal deep tendon reflexes, age of onset, presence of pain, severity of the frontal plane deformity, and sagittal contours were investigated. Results. All 7 patients with a neural axis abnormality on MRI had an early onset disease, and 6 of them had back pain. Thus, age of onset and back pain seem to be predictive of these abnormalities. Frequency of MRI abnormalities was as high as 45% for patients with back pain in addition to a type IC curve. Conclusion. In patients with juvenile idiopathic scoliosis and back pain, preoperative MRI should be performed to eliminate the risk of postoperative neurologic deficits, even if the scoliosis is Lenke type 1. However, in patients with Lenke type 1 idiopathic scoliosis, preoperative MRI studies seem unnecessary if intraoperative neural monitoring is to be performed.