Spinal Cord and Spine
The correlation between lumbosacral sagittal alignment and drift of conus medullaris after transection of the filum terminale in patients with single tethered cord syndrome and its significance
Han Yunfeng, Lai Xuan, Zhang Hua, Sun Jianjun, Han Hongbin, Yang Jun
Published 2020-04-28
Cite as Chin J Neurosurg, 2020, 36(4): 380-384. DOI: 10.3760/cma.j.cn112050-20190809-00348
Abstract
ObjectivesTo investigate the drift of conus medullaris in patients with simple tethered cord syndrome after transection of filum terminale, and to analyze the relationship between the drift of conus medullaris and lumbosacral sagittal alignment and its significance.
MethodsClinical data of 20 patients with tethered cord syndrome admitted to Neurosurgery Department of Peking University Third Hospital from January 2014 to June 2019 were analyzed retrospectively. Lumbosacral angle (LSA), lumbar lordosis angle (LLA), lumbosacral disc angle (LSDA) were measured in all patients′ lumbosacral sagittal MRI before and after operation to evaluate the lumbosacral sagittal alignment. Bending angle (BA) was defined as the acute angle between the longitudinal axis of the conus medullaris and the longitudinal axis of the lumbar spinal cord. The change of BA (△BA) before and after operation was defined as the drift of conus medullaris. The differences of LSA, LLA, LSDA before and after surgery were compared. Pearson correlation was used to analyze the relationship among the △BA, LSA, LLA and LSDA.
ResultsThe preoperative LSA, LLA and LSDA of 20 patients were 69.3°±7.4°, 30.0°±9.5°, 12.0°±4.5°, and the postoperative LSA, LLA, LSDA were 69.8°±7.0°, 30.3°±9.1°, 11.9°±4.5° respectively. There were no significant differences between the preoperative and postoperative angles (all P>0.05). BA was decreased from preoperative 22.3°±6.8° to 20.1°±6.7° after operation (t=9.353, P<0.001). Preoperative LSA of 20 patients was positively correlated with LLA (r=0.576, P<0.01). The △BA was 2.3°±1.1°, which was negatively correlated with preoperative LSA (r=-0.610, P<0.01) and highly negatively correlated with preoperative LLA (r=-0.812, P<0.01).
ConclusionsTo some extent, the drift of conus medullaris could reflect the release of tethered cord after transection of filum terminale in patients with single tethered cord syndrome. Lumbosacral sagittal alignment may affect the drift of conus medullaris, which is helpful for preoperative judgment of the release degree.
Key words:
Neural tube defects; Neurosurgical procedures; Filum terminale transection; Spinal alignment; Conus medullaris drift
Contributor Information
Han Yunfeng
Department of Neurosurgery, Peking University Third Hospital, Beijing 100191, China
Lai Xuan
Department of Geriatric, Peking University Third Hospital, Beijing 100191, China
Zhang Hua
Department of Clinical Epidemiology Centre, Peking University Third Hospital, Beijing 100191, China
Sun Jianjun
Department of Neurosurgery, Peking University Third Hospital, Beijing 100191, China
Han Hongbin
Department of Radiology, Peking University Third Hospital, Beijing 100191, China
Yang Jun
Department of Neurosurgery, Peking University Third Hospital, Beijing 100191, China
