Objective Method discussion of measuring curvature of cervical endplate based on reverse engineering software.Methods The CT scan images data (From C2 to C7) of 8 normal males were selected and inputted into Mimics 10.0 software for 3D reconstruction and separation (cervical spine is divided into C1-C7 isolated reconstructed 3D images).Another software NX Imageware 13.2 is used for further curvature measuring in lines named left,middle,right,anterior,middle,posterior which are derived from each superior and inferior endplate.In each line,15 different points which can perfectly show morphologic characters of the endplate are selected for statistic comparing between different points in the same endplate,different lines in the same endplate,different endplates in the same individual and the same endplate in different individuals.In addition,the correlation between the concavity and the width and depth of endplate is also analyzed.Results From inferior endplate of C2 to that of C6,except superior endplate of C7,there is significant difference between different points in the same line (P＜0.05),while it is opposite in the compare between lines in the same endplate,different endplates in the same individual and the same endplate (except inferior endplate of C4) in different individuals (P＞0.05).It showed significant correlation between the concavity and the width and depth of endplate.Conclusion Reverse engineering software is feasible to be used in evaluate morphologic characters of normal cervical endplate as a new method for measuring the detail parameters of them,it also explore the laws of the curvatures of cervical endplate initially and both of them will be of great use for cervical interbody cage design.

Objective To investigate causes and treatment strategy of cage retropulsion after lumbar interbody fusion.Methods Data of 11 patients with cage retropulsion after lumbar interbody fusion from December 2005 to October 2011 in our hospital were retrospectively analyzed.There were 7 males and 4 females.Their age ranged from 36 to 78 years (average,52.3 years) at the time of the primary operation.Six cases occurred cage retropulsion 0.5 to 3 months after the primary operation,while 5 cases occurred cage retropulsion 14 to 36 months after the primary operation.The causes of cage retropulsion were analyzed.Moreover,corresponding managements were performed and results were recorded.Results The early cage retropulsion was associated with mismanagement of intervertebral space,too much residual of nucleus pulposus,insufficient erasion of cartilage end plate,too small size of cage,malposition of cage,insufficient fixation and so on.The late cage retropulsion was associated with improper choice of surgical strategies,multi-level fusion,preoperative unsteady of vertebrae,advanced age,osteoporosis,diabetes and so on.Three patients underwent conservative treatment and 8 patients underwent revision surgery.All 11 patients were followed up for 6 to 72 months (average,34 months).There was no re-migration of cage,fusion failure,pedicle screw loosening and other complications during the follow-up period.Conclusion The causes of cage retropulsion after lumbar interbody fusion were complex and diverse,and the time of cage retropusion had some clinical value for the cause analysis.It was more advisable to make an individualized treatment program based on the causes of cage retropulsion,clinical manifestations and imaging results.

ObjectiveTo evaluate the surgical techniques and 2-year follow-up results of Mast Quadrant-assisted modified transforaminal lumbar interbody fusion (TLIF).MethodsFrom September 2006 to October 2008,54 patients with single-level lumbar degeneration disease were treated by Mast Quadrantassisted modified TLIF.Under the guidance of C-arm,the Mast Quadrant's retractor was placed and the lower articular process of the upper vertebrae and 1/2-2/3 of the lamina,flavum ligament and hyperplastic cohesive part of the lower articular process were removed,the nerve roots and the central canal were decompressed.After cleaning up intervertebral disc space,bone grafting and pedicle screw fixation were achieved.Visual analogue scale(VAS) and Oswestry disability index(ODI) results,as well as the fusion rate at the last follow-up were analyzed.ResultsAll patients were treated by Mast Quadrant-assisted modified TLIF,in which 51 patients were followed up for 2 years.An average operating time was(178.7±63.2) min,and an average blood loss was (224.2±136.5) ml; an average postoperative drainage loss was (117.2±91.4) ml,and an average postoperative stay was(5.8±3.6) d.There were statistic significances between pre- and post-operative ODI and VAS scores,respectively.At last follow-up,51 patients were achieved radiographic fusion without internal fixation failure and other complications.ConclusionMast Quadrant-assisted modified TLIF had a good vision,was relatively safe and easy to be acceptable by surgeons,and which had a good clinical results for the patients with single-level lumbar degenerative disease.

Objective To explore the electrophysiological charaterstics of upper extremities nerves on the patients with Hirayama disease (HD),amyotrophic lateral sclerosis (ALS),and distal cervical spondylotic amyotrophy (DCSA).Methods The data of electrophysiological examination of the upper limbs of 87 patients with HD,83 with ALS and 28 with DCSA were reviewed retrospectively.Seventy-two patients with HD among 87 had unilateral upper limb's amyotrophy and the other 15 ones had bilateral amyotrophy.There were 30 patients had unilater upper limb's amyotrophy and 53 ones had bilateral amyotrophy from the group of patients with ALS; 20 patients with DSCA were affected unilaterally and 8 ones were bilaterally affected.Results Compound muscle action potential (CMAP) evoked by ulnar stimulation had a lower ampititude compared with that evoked by median stimulation in HD patients.In ALS cases that was just the opposite.However,the CMAPs were similar in DCSA cases.The mean ratio of CMAP amplitude by ulnar stimulation to by median stimulation was 0.58±0.40 in HD group; 2.28±1.25 in ALS and 1.31±0.63 in DCSA.The differences in the three groups were statistical significance.The U/M CMAP ratio was less than 0.6in 62 patients with HD,3 with ALS and 1 with DCSA,and more than 1.7 in 73 cases (57 ALS,12 HD and 4 DCSA).Conduction velocities (CV) of the sensory and motor nerves,the amplitude of the sensory nerve action potential in bilateral limbs,and the CMAP amplitude of the unaffected limb were normal in all cases.Conclusion This study could concluded that the severity of amyotropy in hypothenar mucles were higher than that in thenal muscles in patients with HD; there was just opposite in ALS cases and similar in DSCA.