Résumé
[Objective]To study the method of multi-spiral CT(MSCT) 3D reconstruction technique assisting cervical pedicle screw fixation(PSF) and double-door laminoplasty in the treatment of multilevel degenerative stenosis with traumatic instability(MDSTI) of lower cervical spine.[Method]From September 2006 to August 2007,PSF combined with double-door laminoplasty were performed in 9 patients with MDSTI of lower cervical spine.MSCT 3D reconstruction techniques,including volume rendering(VR) and multi-planar reconstruction(MPR),were used to assist preoperative diagnosis,plan and measurement to guide procedure.Postoperative MPR was used again:through coronal format,the degree of screws perforation was measured precisely and the different positions of pedicle screws were divided into three grades according to Richter's method;through axial format,the increase in sagittal diameter and canal area of every laminoplasty level were measured precisely.A comparison between pre- and postoperative ASIA scores was used to present neural function recovery.[Result]Nine patients with MDSTI of lower cervical spine underwent PSF and total 44 screws.According to the classification of Richter,grade 1 were 72.7%(32/44),grade 2 were 27.3%(12/44).No screw perforation occurred(grade 3) and no screws revision resulted from misplacement.No iatrogenic damage occurred.Double-door laminoplasty was performed in total 42 volumes.The postoperative cervical spinal canal sagittal diameter and traverse area were significantly improved(P