Vol.:(0123456789) 1 3 Surg Radiol Anat DOI 10.1007/s00276-017-1813-3 ORIGINAL ARTICLE Level of conus medullaris termination in adult population analyzed by kinetic magnetic resonance imaging An Liu 1,2  · Kaixiang Yang 1,3  · Daling Wang 1,4  · Changqing Li 1,5  · Zhiwei Ren 1,6  · Shigui Yan 2  · Zorica Buser 1  · Jefrey C. Wang 1   Received: 8 September 2016 / Accepted: 4 January 2017 © Springer-Verlag France 2017 third of T12 (T12U), and 12 = upper third of L3 (L3U)]. All parameters were collected for neutral, fexion and extension positions. Results The level of CMT had the highest incidence (17.61%) at L1 lower (L1L) in neutral position, 17.44% at L1 upper (L1U) in fexion, and 16.92% at L1 middle (L1M) in extension with no signifcant diferences among three positions (p > 0.05) in weight-bearing status. Moreover, the level of CMT was not correlated with age (p > 0.05). In terms of gender, the level of CMT was lower in women than in men in neutral position, fexion, and extension (p < 0.05). Furthermore, when divided by age in decades, there was a signifcant diference between females and males in the age group 60–69 years in neutral, fexion and extension position, respectively (p < 0.05). Abstract Purpose To investigate the change of conus medullaris termination (CMT) level in neutral, fexion and extension positions and to analyze the efects of age and gender on the CMT level. Methods The midline sagittal T2-weighted kinetic mag- netic resonance imaging (kMRI) study of 585 patients was retrospectively reviewed to identify the level of CMT. All patients were in an upright position. A straight line perpen- dicular to the long axis of the cord was drawn from the tip of the cord and then subtended to the adjacent vertebra or disk space. The CMT level was labeled in relation to the upper, middle and lower segments of adjacent vertebra or disk space and assigned values from 0 to 12 [0 = upper A. Liu and K. Yang contributed equally. * Zorica Buser zbuser@usc.edu An Liu liuan@zju.edu.cn Kaixiang Yang yangkxdr@hotmail.com Daling Wang wangdarling@163.com Changqing Li changqli@163.com Zhiwei Ren zwren1980@163.com Shigui Yan zrjwsj@zju.edu.cn 1 Department of Orthopaedic Surgery, Keck School of Medicine, Elaine Stevely Hofman Medical Research Center, University of Southern California, HMR 710, 2011 Zonal Ave, Los Angeles, CA 90033, USA 2 Department of Orthopaedic Surgery, Second Afliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China 3 Department of Orthopedics, The First Afliated Hospital of Soochow University, Soochow University, Suzhou 215006, China 4 Department of Orthopaedic Surgery, Nanjing First Hospital, Nanjing Medical University, Nanjing 210006, China 5 Department of Orthopedics, Xinqiao Hospital, The Third Military Medical University, Chongqing 400037, China 6 Department of Orthopaedic Surgery, The First Afliated Hospital of Xi’an Jiaotong University, Xi’an 710061, China