| Part I Autopsy and imaging studies on the minimally invasive treatment for thoracolumbar fractureObjective: Through the autopsy and imaging studies of adult thoracolumbar vertebral pedicle,to clarify the anatomical and imaging characteristics of the vertebral pedicle,and to provide anatomical and imaging evidence for the minimally invasive treatment for thoracolumbar fracture.Methods:(1)To understand the anatomical and imaging characteristics of the vertebral pedicle through the autopsy and imaging studies of adult thoracolumbar vertebral pedicle:a.Six thoracic and lumbar spine specimens were selected,and the vertebral pedicle was sliced serially in coronal plane by an ultrathin electric saw,to investigate the anatomical morphology of the vertebral pedicle in coronal plane;another 6 thoracic and lumbar spine specimens were selected,and the whole vertebral pedicle was resected and dissociated for sagittal section,to observe the anatomical morphology of the vertebral pedicle in sagittal plane.b.A steel wire was used to tightly wound around the cortex of the narrowest vertebral pedicle in 12 thoracic and lumbar spine specimens for fluoroscopy with a C-arm machine,to understand the imaging morphology of the vertebral pedicle under X-ray fluoroscopy.(2)To explore the best entry points in thoracolumbar pedicle screw placement under X-ray fluoroscopy: Anatomic study was conducted in the thoracic and lumbar spine specimens(T6-L5),and the best entry points under direct vision were fixed by miniscrews for X-ray fluoroscopy,to analyze the position relation between the best entry points under X-ray fluoroscopy and the development of the vertebral pedicle,and thereby seeking for the best entry points under X-ray fluoroscopy.(3)To study the best needling angle for thoracolumbar pedicle screw placement: the mean angle between the central axis of the vertebral pedicle and the sagittal line of the vertebral body of adult thoracic and lumbar spine specimens(T6-L5)was measured by autopsy and CT scanning,respectively.Experimental data were analyzed using statistical software SPSSl3.0,to seek for the best needling angle for thoracolumbar pedicle screw placement.Results:(1)The anatomical morphology of the vertebral pedicle presented a similar round in coronal plane,and whole showed a similar tubular structure;the surface projection of the vertebral pedicle under radiation displayed a circular structure.? The best entry points in thoracolumbar pedicle screw placement under X-ray fluoroscopy: : the left pedicle projection 9 area,right pedicle projection 3 area.?The best needling angle for thoracolumbar pedicle screw placement: L1-L4 of 5 to10 degrees,and the L5 is generally 20 degrees,not more than 25 degrees,thoracic T6-T12 is about 5 degrees.Conclusion:The anatomical characteristics of the vertebral pedicle show a similar tubular structure,and its coronal plane under the radial projection presents a similar circular structure;The best entry points in thoracolumbar pedicle screw placement under X-ray fluoroscopy: : the left pedicle projection 9 area,right pedicle projection 3 area.The best needling angle for thoracolumbar pedicle screw placement: L1-L4 of 5 to 10 degrees,and the L5 is generally20 degrees,not more than 25 degrees,thoracic T6-T12 is about 5 degrees.research on these anatomical characteristics provides an anatomical basis for minimally invasive percutaneous pedicle screw placement for thoracolumbar fracture.Part II: Basic study of the screw track in computer navigation-assisted percutaneous hollow pedicle screw placementObjective: Respectively from the Angle of body anatomy and imaging to study under the navigation design of precision of the orbit,nailing under computer navigation to prove the feasibility of percutaneous pedicle screw orbit design.Methods:(1)Ten bone specimens(T10-L3,a total of 120 vertebral pedicles)were randomly selected,and the preliminary track for pedicle screw was designed based on the best entry points and the best needling angle under computer navigation.The maximum distance from pedicle screw track to the central axis of the vertebral pedicle was measured and recorded.Cases with excellent and good pedicle screw track were treated as positive,while cases with poor track as negative.The number of positive and negative vertebral pedicles among the thoracic and lumbar spines was counted,and the accuracy of pedicle screw track under navigation was analyzed;the number of left and right vertebral pedicles showing positive and negative was counted among the thoracic and lumbar spines.Statistical methods were applied to analyze the positive rate of pedicle screw track for the thoracic and lumbar spines and the difference in the positive rate of pedicle screw track between left and right thoracic and lumbar spines.(2)Ten spinal bones(T10-L3,a total of 40 vertebral pedicles)were randomly selected.Cases treated with computer navigation-assisted percutaneous pedicle screw placement were set as experimental group.Meanwhile,cases treated with screw placement method under direct vision with naked eyes were assigned into control group.The excellent and good rate of screw placement count among the bone specimens of corpses in both groups was counted and analyzed,respectively.Results(1)The measurement of 60 vertebral pedicles in the thoracic spine group,and the design of pedicle screw track: there were 52 excellent cases,3 good cases and 5 poor cases;and positive rata was counted to be 91.67%.The measurement of 60 vertebral pedicles in the lumbar spine group: there were 55 excellent cases,2 good cases and 3 poor cases;and positive rata was counted to be 95.00%.Comparison of the positive rate between thoracic and lumbar spines showed a P > 0.05,suggesting no statistical significance;comparison of the positive rate between left and right thoracic and lumbar spines demonstrated a P > 0.05,indicating no statistical significance.(2)CT scanning was carried out on a total of 30 vertebral pedicles in the navigation experimental group,with an excellent and good rate of screw placement of 96.67%;a total of 30 vertebral pedicles were scanned in the control group,with an excellent and good rate of screw placement of 90.00%.Comparison between these two groups showed a P > 0.05,suggesting no significant difference in the excellent and good rate between the navigation group and the control group,that is,there was no obvious difference in the excellent and good rate of screw placement under navigation and direct vision with naked eyes.Conclusion:(1)The screw track of computer navigation-assisted percutaneous pedicle screw placement for thoracic and lumbar spines is extremely close to the central axis of the vertebral pedicle or located at the central axis of the vertebral pedicle,and the pedicle screw track designed under navigation is ideal.(2)The excellent and good rate of screw placement among the bone specimens of corpses shows no apparent difference under navigation and direct vision with naked eyes.Therefore,it can be inferred that the pedicle screw track designed with computer navigation-assisted percutaneous placement is feasible.Part III Efficiency analysis of navigation-assisted minimally invasive screw placement and conventional percutaneous minimally invasive screw placement in the treatment of thoracolumbar fractureObjective: To compare and evaluate the efficiency of navigation-assisted minimally invasive and conventional percutaneous minimally invasive methods in the treatment of thoracolumbar fracture in young adults.Methods: From August 2013 to August 2015,a total of 41 patients were screened for our study and divided into experimental group(computer navigation-assisted percutaneous long-tail hollow pedicle screw technique group)and control group(conventional X-ray fluoroscopy-guided percutaneous minimally invasive pedicle screw technique group).Mean operative time,hemorrhage,the excellent and good rate of screw placement,and mean frequency of X-ray fluoroscopy of the two groups were recorded;and postoperative incision pain of the two groups were observed using VAS scoring.Results: The frequency of intraoperative X-ray in the experimental group was evidently lower than that in the control group(P < 0.01);the excellent and good rate of screw placement in the experimental group was superior to that in the control group(P <0.05);mean hemorrhage and operative time showed no statistical significance between the experimental group and the control group;postoperative incision pain of both groups was evaluated using VAS scoring,demonstrating no statistically significant difference.Conclusion: As compared with conventional X-ray fluoroscopy-guided percutaneous minimally invasive pedicle screw technique,navigation-assisted percutaneous minimally invasive hollow pedicle screw technique has multiple advantages,such as less trauma,lower frequency of X-ray exposure,and higher excellent and good rate.In addition,navigation-assisted minimally invasive screw placement is safer and worthy of clinical application.Part IV Efficiency analysis of computer navigation-assisted minimally invasive and conventional open surgery in the treatment of thoracolumbar fractureObjective: To compare and evaluate the efficiency of navigation-assisted minimally invasive and conventional open surgery in the treatment of thoracolumbar fracture in young adults.Methods: From September 2013 to December 2015,a total of 38 patients were screened for our study and randomly divided into minimally invasive group and open surgery group.The minimally invasive group was treated with computer navigation-assisted percutaneous minimally invasive long-tail folded hollow pedicle screw placement and percutaneous reduction and internal fixation;while the open surgery group was treated with conventional posterior open reduction and internal fixation with pedicle screw.Mean operative time,hemorrhage,incision length,the excellent and good rate of screw placement,and mean frequency of X-ray fluoroscopy of the two groups were recorded;postoperative incision pain of the two groups were observed using VAS scoring;preoperative and postoperative Cobbs angle recovery of the two groups were observed.Results: Mean operative time,the amount of hemorrhage,the frequency of X-ray exposure and incision length were all less in the minimally invasive group as compared with the open surgery group(P < 0.01);the excellent and good rate of screw placement showed no statistically significant difference between the navigation-assisted minimally invasive group and the open surgery group(P > 0.05).Comparison of postoperative pain(VAS score at postoperative day 2)presented a significant difference between the navigation-assisted minimally invasive group and the open surgery group(P < 0.05).To be more specific,postoperative pain symptoms were apparently improved in the minimally invasive group as compared with the open surgery group.Changes in Cobbs angle before and after the operation of the two groups were examined by the paired t-test,which showed that P < 0.05 and there is an obvious difference in the changes of Cobbs angle before and after the operation in the two groups,suggesting the surgery treatment had marked significance.In addition,comparison of the changes in preoperative and postoperative Cobbs angle between the minimally invasive group and the open surgery group was examined by the t-test,demonstrating P > 0.05 and no statistical significance in Cobbs angle improved value between the two groups.Conclusion: Computer navigation-assisted minimally invasive hollow pedicle screw technique is characterized by less trauma,ability to reduce soft tissue complication,good accuracy in screw placement,and excellent efficiency in the treatment of thoracolumbar fracture in young adults;moreover,this technique can reduce the iatrogenic radiation injuries caused by minimally invasive surgery,and is a safe,reliable and effective minimally invasive treatment technology. |
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