Magnetic resonance imaging investigations of position of conus medullaris in adolescent idiopathic scoliosis as a peripheral neuropathy

Adolescent idiopathic scoliosis (AIS) is a structural 3-dimensional deformity the spine, which is occurring between 10 years of age and skeletal maturity and it mostly affects prepuberbal girls. The etiology of AIS remains unknown and seems should be multifactorial. According to the theories, there could be a shorter spinal cord or a higher location of the conus medullaris and disproportionate growth in neuro-osseous system. This study wants to investigate the position of the conus medullaris in AIS patients with a large curve magnitude in comparison with healthy adolescents. 94 AIS patients consisting of 25 males and 69 females between 11 and 25 years old, based on physical examination and standing posteroanterior roentgenography of the total spine with a Cobb angle more than 40 degrees was chosen. The main curve magnitude of every AIS patient was measured by the Cobb method. Apex of deformity was determined based on SRS definition. Patients' deformity were calcified based on Lenke classification. Magnetic resonance imaging examinations of the total spine were performed in the AIS group, by means of a 1.5-T magnetic resonance imaging system. The position of conus medullaris was defined according to the method by saffiudin et al and was assessed based on the age, sex, type of deformity, severity of deformity, kyphosis, lordosis, flexibility, apical vertebra, stable vertebra. The mean age of patients were 16.34 with 6.77 of conus medullaris position in mean, which was lower one-third of L1. Our study showed no significant correlation between the position of conus medullaris with age, weight, preoperative curve, flexibility, types of deformity based on Lenke classification and degree of kyphosis and lordisis. In conclusion, there is the same mean and the distribution of the conus medullaris locations for AIS patients and normal populations.