ORIGINAL ARTICLE Predicted cervical canal enlargement and effective cord decompression following expansive laminoplasty using cervical magnetic resonance imaging Mohd Imran Yusof • Eskandar Hassan • Shafie Abdullah Received: 17 September 2009 / Accepted: 14 July 2010 / Published online: 24 July 2010 Ó Springer-Verlag 2010 Abstract Background Posterior translation of the spinal cord occurs passively following laminoplasty with the pres- ence lordotic spine and availability of a space for the spinal cord to shift. This study is to predict the distance of posterior spinal cord migration after expansive laminopl- asty at different cervical levels based on measurement of posterior translation of the spinal cord in normal cervical morphometry. Methods Measurements were performed from C34, C45, C56 and C67 disc using magnetic resonance imaging (MRI) images. Apical level of the cervical curve, lordotic angle, spinal cord diameter, spinal canal diameter, space anterior to the cord and spinal canal/cord ratio were determined before and after postulated laminoplasty. Sta- tistical analysis was performed to assess the significance of the canal enlargement and effective spinal cord decom- pression at each level. Results The predicted spinal canal decompression achieved at C34, C4C5, C56 and C67 levels were 48.8, 71.9, 84 and 86.5%, respectively. The mean measurement of spinal canal after laminoplasty was 16.7 mm with spinal canal diameter increased between 3.5 and 5.6 mm. Space anterior to the cord after laminoplasty increased to between 8.6 and 10.9 mm. There was significant correlation between Cobb’s angle and spinal canal diameter post laminoplasty at C45, C56 and C67 but no significant cor- relation between Cobb’s angle and space anterior to the cord post laminoplasty was found. Conclusions Laminoplasty may produce larger canal expansion at the lower cervical spine compared to the upper cervical area; therefore, the outcomes of those who have predominantly higher cervical myelopathy were inferior to those who have lower cervical myelopathy. Keywords Cervical myelopathy Á Laminoplasty Á Spinal canal expansion Á Magnetic resonance imaging Introduction Cervical laminoplasty has been performed widely for multiple level myelopathy. Since it was firstly reported, various modifications had been done to improve the effectiveness [6, 21]. Long term outcome of the procedure had been published and favorable results had been reported [5, 15, 18, 19]. Complications following cervical lamin- oplasty were also known and associated factors leading to failure of this surgery had been recognized [11–13]. The mechanism of cord decompression following laminoplasty was due to posterior translation of the spinal cord following expansion of the spinal canal [2]. Kimura et al. [9] reported that kyphotic and sigmoid cervical spines had poorer operative results, because the spinal cord was draped over the posterior aspect of anterior compressing structures. Therefore, presence of cervical lordosis is an important factor for the effectiveness of this procedure. Loss of cer- vical lordosis following laminoplasty had been reported leading to neurological deterioration [14]. M. I. Yusof (&) Á E. Hassan Spine Unit, Department of Orthopaedics, School of Medical Science, USM, 16150 Kubang Kerian, Kelantan, Malaysia e-mail: drimran@kb.usm.my; drimran93@yahoo.com S. Abdullah Department of Radiology, School of Medical Science, USM, 16150 Kubang Kerian, Kelantan, Malaysia 123 Surg Radiol Anat (2011) 33:109–115 DOI 10.1007/s00276-010-0704-7