Objective To discuss the short-term effect of Sextant system fixation for thoracolumbar fractures without neurological deficit in the field comprehensive operation rescue shelter.Methods There were 32 patients with thoracolumbar fractures without neurological deficit which rescued by our hospital.Those patients included 18 males and 14 females, with average age of (25.54±2.86) years old.All patients were undergoing internal fixation with Sextant system in the field comprehensive operation rescue shelter.Clinical and surgical evaluation including surgery time,intraoperative blood loss,postoperative ambulation time and wound healing time were observed.Functional outcomes of pre-operation and postoperation 3-days were evaluated by visual analog scale(VAS) and Oswestry disability index(ODI).Cobb angle and front height of fracture vertebral body were compared between pre-operation and postoperation 3-days.Results The operation time was (96.55±14.15)minutes, intraoperative blood loss was (45.25±3.55)mL, postoperative ambulation time was (1.20±0.61)days.There were statistical differences in terms of Cobb angle,front height of fracture vertebral body,VAS and ODI between pre-operation and postoperation 3 days.Conclusion The Sextant system fixation in the field comprehensive operation rescue shelter is a timely,safe and effective method for thoracolumbar fractures without neurological deficit,which is deserved to utilize at the scene when war or disaster urgency treatment.

Objective The aim of this study was to provide methods for predicting ideal trajectory and position of C1 lateral mass screw (C1 LMS)from plain radiographs.Methods A total of 40 consecutive subjects (with 79 screws)who had undergone C1 LMS placement were enrolled.To evaluate the C1 LMS position,the positions of screw head and tips on anteroposterior radiographs,screw length,and height on lateral radiograph were graded as 0°,Ⅰ°,and Ⅱ°,respectively.On the postoperative computed tomography images,the lateral mass (LM) perforation,screw-thread engagement percent(%),bicortical fixation,extruded screw length,and violation of adjacent joints were analyzed. Results Screws with tip located medial to LM(tip 0)showed LMperforation in all cases.Polyaxial head located within the LM(head 0)or crossing the lateral margin of the LM(head Ⅰ)showed no LMperforation.Screw-thread engagement percent was the highest with head Ⅰ-tip Ⅰ (medial half of LM)position (97.6%),followed by head 0-tip Ⅰ (90.5%)and head Ⅰ-tip Ⅱ (lateral half of LM)(86.4%). Screws longer than the posterior half of C1 anterior arch (AA)showed bicortical fixation in all cases with mean extruded screw length of 1.9 mm.Adjacent joint was not violated in 98%,with the screw height below half of C1 AA.Conclusion On an anteroposterior radiograph, a C1 LMS with the screw head located on the lateral margin of the LMand with the screw tip in the medial half of the LMresulted in the safest and longest trajectory.On lateral radiograph,a screw tip that is placed within the anterior-inferior quadrant of the C1 AA results in safe bicorti-cal fixation without injury to the adjacent structures.These plain radiographic findings may be helpful bothpostoperatively and intraoperatively for assessing the trajectory and length of the screw.

Objective To evaluate the clinical and radiological factors which affecting the recovery duration of C5 palsy after cervical decompression surgery.Methods The datas of 710 patients with degenerative cervical spine surgery in departement of spine surgery of orthopaedics of general hospital of Shenyang military region were retrospectively analyzed.The demographics,radiology,clinical information were recorded to analyze the relationship with the recovery duration of postoperative C5 palsy.Results C5 nerve root palsy occurred in 36 cases,of which 33 cases completely recovered within 2 years after surgery(18 cases recovered within postoperative 6 months),3 cases did not completely recovered during the following period.Factors related to longer recovery(over 6 months) included postoperative limbs muscles strength ≤2(P＜0.01),presence of multi-segment paresis involving more than the C5 root(P =0.002),loss of somatic sensation with pain(P =0.008),and the degree of posterior spinal cord shifting (P =0.040).Furthermore,multivariate analysis revealed that postoperative limbs muscles strength ≤2(P =0.010) had a significant effect on a recovery duration beyond 6 months.Conclusion The postoperative limbs muscles strength ≤2,the presence of multi-segment paresis involving more than the C5 root,the loss of somatic sensation with pain,and the degree of posterior spinal cord shifting are main factors which significantly influence the duration of recovery from postoperative C5 nerve root palsy.

Objective To discuss the recent clinical efficacy of percataneous pedicle screw internal fixation for thoracolumbar fractures without neurological deficit in the new field comprehensive operation rescue shelter at the war or disaster treatment place.Methods Retrospectively analyzed the clinical data of 29 patients with thoracolumbar fractures who were rescued by our hospital.Those patients included 18 males and 11 females,with the average age of (31.54±2.86) years old.All these patients underwent percutaneous pedicle screw internal fixation in the new field comprehensive operation rescue shelter.Clinical and surgical evaluation including surgery time,blood loses,exercise time after operation and complications.Functional outcomes of pre-operation and post-operation were evaluated by visual analog scale (VAS) and Oswestry disability index (ODI).Cobb's angle and fracture vertebral body front height were compared before and after operation as well.Results All these patients were all successfully completed operation in the field comprehensive operation rescue shelter,and the general post-operation condition was well.The operation time was (86.55±16.15)min,the blood loss was (42.35±6.55)mL,the exercise time after operation was (1.20±0.61) days.There was no complications after operation, and pain of thoracolumbar after operation was obviously alleviated.There was statistical differences in terms of Cobb's angle,fracture vertebral body front height,VAS score and ODI score between pre-operation and post-operation (P<0.05).Conclusion The percataneous pedicle screw internal fixation in the new field comprehensive operation rescue shelter is a quite effective method for thoracolumbar fractures without neurological deficit, and this method is worthy of promoting at the scene when war or disaster urgency treatment.

Objective The purpose was to compare the biomechanical characteristics of new percutaneous guide wire and conventional wire in cadaveric spines,and to evaluate the new percutaneous guide wire's efficacy and safety in a clinical trial.Methods Compared the push-out and penetration forces of the new percutaneous guide wire and conventional wire in fresh cadaveric lumbar spines from L1 to L5.And analyzed the related complications of new percutaneous guide wire by clinical experiment.Results Push-out forces caused the spiral part of the new percutaneous guide wire to bend or spread,so as to resist the anterior migration of the guide wire.The mean push-out forces of the new percutaneous guide wire and conventional wire were (15.5-+ 1.9) N and (5.7 ± 0.8) N respectively (P ＜ 0.01),and the mean penetration forces were (69.1 ±4.2) N and (37.1 ±4.8) N respectively (P ＜0.01).There was no wire breakage or anterior-wall penetration in the clinical trial of 222 new percutaneous guide wire.Conclusion The mean push-out and penetration forces of the new percutaneous guide wire were approximately 2 to 3 times greater than those of conventional wire.The new percutaneous guide wire effectively prevented guide-wire anterior migration and penetration of the anterior vertebral-body wall.The new percutaneous guide wire device could effectively improve the safety of percutaneous pedicle screw insertion procedures for patient with osteoporosis.

Objective To compare the clinical complications between S2 alar-iliac(S2AI) screw and iliac screw(IS) fixation technique.Methods The data of 65 patients who were diagnosed as degenerative scoliosis and underwent spinopelvic fixation in our hospital from August 2010 to July 2012 were retrospectively reviewed.These patients were divided into the iliac screw fixation group (IS group) with 43 patients and the S2 alar iliac fixation group (S2AI group) with 22 patients according to different methods.The complications included screw loosening,screw breakage,acute infections,delayed wound infection and persistent pain over the gluteal region occurring longer than 3 months postoperatively were recorded.Results There were 8cases with screw loosening and 13 cases with gluteal pain in IS group,while there were no screw loosening and only 2 cases with gluteal pain in S2AI group.The average onset of gluteal pain were 11.8 months postoperatively in the IS group and 18 months postoperatively in the S2AI group.It showed that the absolute risk reduction(ARR) of screw loosening and late pain in the S2AI group was 18.6%,which was lower than 21.1% in the IS group. In the IS group, there were a total of 5 cases of delayed wound infection. Finally,3 caes of them were cured by irrigation and debridement only.and the other 2 cases were cured by irrigation and debridement with implant removal.There were no cases of delayed wound infection in the S2AI group.Conclusion The S2AI technique is associated with significantly less clinical and radiographic complications when compared with the iliac screws technique,it is a kind of internal fixation of spine and pelvis,which is worthy of being popularized by spine surgeons.

Objective:To compare the optimal gridpercutaneous vertebroplasty (PVP) and conventional PVP in the treatment of osteoporotic vertebral compression fractures (OVCFs).Methods:A retrospective cohort study was conducted of 102 patients with OVCFs who had underwent PVP between May 2016 and May 2019 at department of spine surgery, General Hospital of Northern Theater Command. According to the different surgical methods, they were divided into the optimalgrid PVP group (102 cases) and conventional PVP group (94 cases). In the optimal grid PVP group, there were 38 males and 64 females with an average age of 67.3±8.5 years old, and the course of disease was 2.3±1.2 days; the injured sites were lumbar vertebra, including 59 cases of L 1 vertebra, 31 cases of L 2 vertebra, 8 cases of L 3 vertebra, 3 cases of L 4 vertebra and 1 case of L 5 vertebra. In the conventional PVP group, there were 26 males and 68 females with an average age of 71.5±5.6 years old, and the course of disease was 2.1±1.1 days; the injured sites were lumbar vertebra, including 52 cases of L 1 vertebra, 33 cases of L 2 vertebra, 7 cases of L 3 vertebra and 2 cases of L 4 vertebra. The patients were prepared before operation. Then the best puncture point was selected, and the guide wire and working channel were inserted. Finally the bone cement was pushed. The operation time, intraoperative fluoroscopy times, bone cement dosage and bone cement leakage were compared between the two groups. Visual analogue scale (VAS), anterior heights and median heights of injured vertebra were compared between the two groups at postoperative 3 days, 3 months and the final follow-up. Results:There were no significant differences in the general clinical data between the two groups before operation ( P>0.05). All patients had no complications such as wound infection,pulmonary embolism,spinal cord embolism or death. The operation time, fluoroscopy times, bone cement dosage and bone cement permeability of the two groups were statistically significant different ( P<0.05), and the optimal grid group was better than the conventional group. VAS at 3 days, 3 months and the final follow-up was statistically significantlower in the optimal grid group than the conventional group ( P<0.05). There was no significant difference in the recovery of the anterior and middle edge heights of injured vertebra in the two groups 3 days after operation ( P>0.05), but there were statistical significant difference between the two groups3 months after operation and at the last follow-up ( P<0.05), whilethe optimal grid group was better than the conventional group. Conclusion:Compared with conventional PVP, the optimal grid PVP is safer and more effective in the treatment of osteoporotic vertebral compression fractures.

Objective To analyze the short-term clinical efficacy of percutaneous kyphoplasy in treating aged patients with osteoporotic vertebral compression fractures in a field comprehensive operation rescue shelter at the disaster site.Methods The clinical data of 43 aged patients with osteoporotic vertebral compression fractures (51 diseased vertebrae in total),who received treatment during the period from April 2013 to August 2016 in a field comprehensive operation rescue shelter at the disaster site,were retrospectively analyzed.After injury,the patients were immediately sent to the field comprehensive operation rescue shelter,which was developed by authors' institute,to receive percutaneous kyphoplasy.The average operation time,preoperative and postoperative pain visual analogue scale (VAS) scores,the manifestations of Cobb'angle of the corresponding segment that was determined on lateral radiography,and the changes in anterior,middle and posterior height of the vertebrae were documented.Results The average operation time was (52.34±14.76) min.The postoperative VAS scores were significantly decreased when compared to the preoperative ones (P＜0.01).After percutaneous kyphoplasy,the Cobb'angle of the coresponding segment of injured vertebrae was obviously improved (P＜0.01),moreover,the anterior,middle and posterior height of the injured vertebrae was remarkably restored (P＜0.01).Conclusion In treating osteoporotic vertebral compression fractures in aged patients,percutaneous kyphoplasy,that is used as an emergency treatment and is carried out in a field comprehensive operation rescue shelter,is quite effective.This treatment can reliably relieve the severe pain caused by compression fracture and improve the prognosis as well.

Objective To compare the biomechanical characteristics of a novel guide wire with that of the conventional guide wire by using cadaver specimen test,and to evaluate the safety and effectiveness of this new guide wire through clinical experiment.Methods By using cadaver specimen test,the average push-out force on the guide wire and the extra-force required to penetrate the anterior wall of the vertebral bodies,from L1 to L5,were determined,and the results were compared between the novel guide wire and the conventional guide wire.Results The definition of push-out force was a force that caused the tip of the guide wire to bend or disperse within the vertebral body and then the further moving of the wire to the front of the vertebral body was impeded.The average push-out forces for the novel guide wire and the conventional guide wire were (15.5±1.9) and (5.7±0.8) newton respectively (P＜0.001).The mean force required to penetrate the anterior wall of the vertebral body for the novel guide wire and the conventional guide wire were (69.1±4.2) and (37.1±4.8) newton respectively (P＜0.000 5).A total of 222 novel guide wires were used in clinical trial,and no penetration of vertebral anterior wall by the guide wire occurred.Conclusion The average push-out force within the vertebral body and the mean force required to penetrate the anterior wall of the vertebral body for the novel guide wire are about 2 times and 3 times greater than those for the conventional guide wire respectively.The use of this novel guide wire can effectively prevent the wire from moving forward in the vertebral body as well as from penetrating the vertebral anterior wall.Therefore,the use of this novel guide wire can reliably improve the safety for patients with osteoporosis receiving percutaneous pedicle screw insertion procedure.

Objective To evaluate the short-term efficacy of percutaneous S2-alar-iliac screw (S2AIS) fixation for the treatment of lower lumbar spondylodiscitis with no neurological symptoms in elderly patients.Methods The clinical data of 28 patients of lower lumbar spondylodiscitis with no neurological symptoms,who were admitted to the Ward of Spine,Department of Orthopaedics,General Hospital of Shenyang Military Region,China,to receive percutaneous S2AIS fixation,were retrospectively analyzed.The operation was performed by the same surgeon for all patients.A total of 56 S2AIS fixation procedures were accomplished.The patients' age varied from 71 to 79 years old.The spondylodiscitis was located at IAL5 or L5-S1.After the treatment,the patients were followed up for a mean of 6.67 months.The mean operative time,the amount of intraoperative blood loss,the postoperative bed time,the average hospitalization days and the postoperative wound healing were documented and analyzed.The Oswestry score,visual analogue score,erythrocyte sedimentation rate,C reactive protein level were determined before operation as well as at one week and 6 months after operation,and postoperative CT was performed to check the loosening of internal screw fixation.The results were compared and analyzed.Results The mean operative time was (158.12±4.32) min,the average amount of intraoperative blood loss was (25.34±3.23) ml,the average postoperative bed time was (1.34±0.35) d,and the average hospitalization time was (7.29±1.34) d.Poor surgical incision healing was seen in only one patient,and the postoperative wound healing rate was up to 96.42％.Loosening of right S2AIS was detected in one patient,with the screw loosening rate being 1.79％.The Oswestry scores determined at one week and 6 months after treatment were 32.21 and 23.20 respectively,which were significantly different from the preoperative score (P＜0.05).The visual analogue scores determined at one week and 6 months after treatment were 2.17 and 1.25 respectively,which were significantly different from the preoperative score (P＜0.05).At one week and 6 months after treatment,the erythrocyte sedimentation rates were 15.32 mm/h and 14.56 mm/h respectively,and the C reactive protein levels were 7.89 mg/L and 8.90 mg/L respectively,both of which were significantly different from the preoperative ones (both P＜0.05).Conclusion For the treatment of lower lumbar spondylodiscitis with no neurological symptoms in elderly patients,percutaneous S2AIS fixation has certain advantages,such as less trauma,less blood loss,early postoperative ambulation,remarkable improvement of clinical symptoms,etc.with satisfactory short-term clinical efficacy.