Objective To investigate the effect of percutaneous lordorizing screws fixation for correcting kyphosis in thoracolumbar burst fractures and treatment strategies.Methods A retrospective case control study was designed to analyze data of 97 patients with single-level thoracolumbar burst fractures without neurological deficits undergone percutaneous lordorizing screw fixation from April 2010 to March 2015.According to the different surgical procedures,the patients were divided into Group A (percutaneous transpedicle fixation,n =47) and Group B (percutaneous transpedicle fixation combine lordorizing screw fixation,n =50).Each group was subdivided based on the preoperative segmental kyphosis:Group A consisted subgroups A1 (kyphosis angle≤ 10°,n =11),A2 (kyphosis angle between 10° and 20°,n =20) and A3 (kyphosis angle ≥ 20°,n =16),and Group B consisted of subgroups B1 (kyphosis angle ≤ 10°,n =16),B2 (kyphosis angle between 10° and 20°,n =16) and B3 (kyphosis angle ≥ 20°,n =18).Length of hospital stay,operation time,blood loss,visual analogue scale (VAS) and Oswestry disability index (ODI) were compared between groups.Segmental kyphosis angle and vertebral wedge angle were compared between subgroups before operation,after operation and at the final follow-up.Results All patients were followed-up for 12-37 months (mean,21.2 months).There were no significant differences between the two groups in aspects of length of hospital stay,blood loss,VAS and ODI (P ＞ 0.05).Operation time was (60.62 ± 9.59) min in Group A,significantly less than that in Group B [(74.78 ± 17.66) min] (P ＜ 0.05).No breakage or malfunction of fixation occurred.There were no significant differences between the two groups in preoperative segmental kyphosis angle (P ＞ 0.05),while the correction of segmental kyphosis angle in Group B was better than Group A at the final follow-up [(7.97 ± 5.09) ° vs.(3.76 ± 1.67) °] (P ＜ 0.05).At the final follow-up,the correction of segmental kyphosis angle was similar between Group A1 and Group B1 (P ＞ 0.05),but the correction in Group B2 was better than GroupA2 (P ＜0.05) and the correction in Group B3 better than Group A3 (P ＜ 0.05).Besides,the correction of vertebral wedge angle was similar between Group A1 and Group B1 (P ＞ 0.05),but the correction in Group B2 was better than Group A2(P ＜0.05) and the correction in Group B3 was better than Group A3 (P ＜ 0.05).Loss of segmental kyphosis angle and vertebral wedge angle in Group A were greater than these in Group B (P ＜ 0.05).Conclusions Combined use of lordorizing screw with percutaneous transvertebral fixation improves the correction of thoracolumbar kyphosis angle in single-level thoracolumbar burst fractures.When the preoperative segmental kyphosis over 20°,lordorizing screw fixation should be recommended so as to achieve better correction of kyphotic deformity.

Objective To determine the appropriate size of the tube for the thoracic drainage in good efficiency by the experimental study in the influence of the tube size on the flow rate of the fluid with different properties.Methods Three groups were divided according to the different components in the fluid:group A,whole blood with 30％ hematocrit; group B,2.5％ albumin solution; and group C,0.9％ normal saline.The total volume of the fluid was 1000 mL in each group in the experiment.Different sorts of fluids were drained with the chest tubes with different diameters (6F,8F,10F,12F,14F,16F,18F,20F,22F,24F,26F,28F,30F,32F,34F,36F of French F) separately,and the flow rate was calculated.ANOVA was used for the comparison of the differences in flow rate among the groups with given fluid property.Twofactor analysis of variance was used for the analysis of flow rates of fluid with different fluid properties.Curve fitting was performed according to the Poiseuille formula.Results The flow rate was positively correlated with the size of the chest drainage tube.The difference in flow rate among the tubes with difference in size was statistically significant (P ＜ 0.05) but there was no noticeable difference in flow rate between 6F and 8F (P =0.513).The flow rate of the 6F and 8F tubes was higher than that of the control (3.33 mL/min) but there was no significant difference between them (P ＞ 0.05).The flow rate of the tubes in 10F and above was obviously higher than that of control (P ＜ 0.05).The curve was estimated that group A was Q =0.002 9x4,R2 =0.991; group B Q=0.003 2x4,R2 =0.981; group C Q =0.003 4x4,R2 =0.975.When the flow rate was fixed at 3.33 mL/min,the estimated curve in group A was X ≈ 5.82F.Conclusions Our experiment indicated that the chest tube with small diameters (6F-14F) could meet the demand of high efficient drainage in the patients with hemothorax or pleural effusion.

Objective To establish the method for the content determination of sinomenine in Qiwei Tongbi oral liquid. Methods Sinomenine ofQiwei Tongbi oral liquid was determined by HPLC, with the column being Waters XTerra column temperature setting at 25℃, flow rate being 1.0 ml/min, and the detective wavelength being 262 nm. Results There was a good linearity of sinomenine in the range of 0.248～2.480 μg, and the average recovery was 98.82% with RSD of 0.13%. Conclusion This method was simple, accurate, reproducible, and thus could be used for quality control of Qiwei Tongbi oral liquid.

Objective To investigate the relationship between the facet angle (FA) and facet violation in percutaneous pedicle screw placement in lumbar vertebrae.Methods From December 2013 to November 2016,atotal of 115 lumbar fracture or degenerative disease patients who had undertaken percutaneous pedicle screw operation was retrospectively analyzed.There were 56 males and 59 females,with an average age of 53.71±12.19 years (ranged from 15 to 77 years).Measure the FA at the level of pedicle through CT scan,diagnosis and evaluate the grade of facet joint violation after the operation.Analyzed the effect of variant FA and lumbar segment (L-L5) on the facet violation (FV) with two-way analysis of variance,and evaluate the correlation between the FA and FV in percutaneous pedicle screw placement.Results There was no significant difference between the two groups on age,gender,and body mass index.476 percutaneous pedicle screws were operated in this study:L1 144 screws,L2 136 screws,L3 64 screws,L,72 screws and L5 60 screws.The total FV rate was 30.46％ (145/476).344 screws in the upper lumbar group,and the FV rate was 28.78％ (99/344);132 screws in lower lumbar group,and the FV rate was 34.85％ (46/132).There was no significant difference of FV rate between the two groups (x2=1.66,P=0.20).The result of two-way analysis of variance indicated that the FV rate increased dramatically when FA ＞ 35° (F=20.12,P ＜ 0.001),but FV rate was not related to the lumbar segment statistically (F=0.93,P=0.45).Spearman rank correlation analysis was performed between FA and FV rate,FV grade.The result was both positive (r=0.25,P ＜ 0.001 and r=0.27,P ＜ 0.001).Conclusion The traditional C-arm fluoroscopy percutaneous pedicle screw placement technique has a high rate of FV,and the size of FA significantly affects the incidence and severity of FV.

OBJECTIVE: To investigate the potential risk of approach-related complications at different access angles in minimally invasive lateral lumbar interbody fusion.METHODS: Eighty-six axial magnetic resonance images were obtained to analyze the risk of approach-related complications. The access corridor were simulated at different access angles and the potential risk of neurovascular structure injury was evaluated when the access corridor touching or overlapping the corresponding structures at each angle. Furthermore, the safe corridor length was measured when the corridor width was 18 and 22 mm.RESULTS: When access angle was 0°, the potential risk of ipsilateral nerve roots injury was 54.7% at L4–L5. When access angle was 45°, the potential risk of abdominal aorta, contralateral nerve roots or central canal injury at L4–L5 was 79.1%, 74.4%, and 30.2%, respectively. The length of the 18 mm-wide access corridor was largest at 0° and it could reach 44.5 mm at L3–L4 and 46.4 mm at L4–L5. While the length of the 22 mm-wide access corridor was 42.3 mm at L3–L4 and 44.1 mm at L4–L5 at 0°.CONCLUSION: Changes in the access angle would not only affect the ipsilateral neurovascular structures, but also might adversely influence the contralateral neural elements. It should be also noted to surgeons that alteration of the access angle changed the corridor length.
Aorta, Abdominal ; Magnetic Resonance Imaging ; Surgeons

Objective:To investigate the influence of different degrees of facet joint arthropathy on the indirect decompression effect of crenel lumbar interbody fusion (CLIF), and the clinical outcomes of CLIF for the treatment of lumbar spinal stenosis with severe facet joint arthropathy (grade 3).Methods:This study reviewed a total of 269 surgical segments in 156 patients with lumbar spinal stenosis treated with CLIF technique from November 2016 to February 2020. According to preoperative CT images, the facet joint was graded according to Pathria classification. There are 19 segments with grade 0, 156 segments with grade 1, 67 segments with grade 2, and 27 segments with grade 3. Radiographic parameters included disc angle, anterior and posterior disc height, and bilateral intervertebral foramen height on CT, and the midsagittal canal diameter and axial central canal area. In 30 patients with at least one segment of grade 3, the clinical efficacy was assessed using visual analogue scale (VAS) and Oswestry disability index (ODI).Results:The average the anterior and posterior intervertebral space height, intervertebral space angle, height of bilateral intervertebral foramina, spinal canal sagittal diameter and spinal canal area were significantly improved after the operation of grade 3 facet joint degeneration segment compared to preoperation. The preoperative mean spinal canal sagittal diameter and spinal canal area of grade 3 facet joint degeneration segment were significantly less than grade 1 and grade 2. The average change of spinal canal area after grade 3 articular degeneration was significantly less than that of grade 1 and 2, but there was no significant difference with that of grade 0. The posterior decompression rate was 55.56% (15/27) for grade 3, 35.82% (24/67) for grade 2, 16.03% (25/156) for grade 1, and 21.05% (4/19) for grade 0. The posterior decompression rate of grade 3 articular process degeneration was significantly higher than that of other grades ( P<0.001). Severe lateral recess stenosis and 24.24% of severe intervertebral foraminal stenosis were found in 81.48% of grade 3 degenerative segment. The 23 patients were followed up with an average of 21.62±6.52 months, and the average improvement of ODI was 24.10%±11.09%; the average VAS for leg pain and back pain were improved significantly. Conclusion:The degrees of facet joint degeneration do not prevent intervertebral space distraction of CLIF. However, because segments with severe facet joint arthropathy were usually associated with severe spinal canal stenosis, CLIF had a high rate of second-stage posterior decompression in the treatment of lumbar spinal stenosis with severe facet joint arthropathy.

Objective To explore the effect of mucle force on contact force, peak pressure and contact area of foot joint in in vitro biomechanical experiment of foot and ankle, so as to provide references for choosing appropriate loading modes. Methods In neutral position of the ankle joint, fresh calf and foot specimens were simulated with or without mucle force loading. The contact force, peak pressure and contact area of the 1st metatarsophalangeal joint, the 2nd metatarsophalangeal joint, the 1st tarsometatarsal joint, the 2nd tarsometatarsal joint, the medial cuneonavicular joint, the intermediate cuneonavicular joint, the talonavicular joint, the calcicocuboid joint, the subtalar joint ( posterior articular surface) and the tibiotalar joint of normal foot under loading were measured, the results are compared and analyzed. Results Under muscle force loading, the contact force of the 1st metatarsophalangeal joint, the 2nd metatarsophalangeal joint, the 1st tarsometatarsal joint,the 2nd tarsometatarsal joint, the medial cuneonavicular joint, the intermediate cuneonavicular joint, the talonavicular joint and the tibiotalar joint were significantly greater than those without muscle force loading (P<0. 05), and the change percentages were 719. 28% , 311. 37% , 128. 67% , 50. 82% , 54. 89% , 57. 63% ,79. 98% and 50. 34% , respectively. The peak pressures of the 1st metatarsophalangeal joint , the 1st tarsometatarsal joint and the talonavicular joint under muscle force loading were significantly higher than those without muscle force loading ( P < 0. 05), and the change percentages were 176. 14% , 62. 91% and 40. 07% ,respectively. The contact area of the 1st metatarsophalangeal joint, the 1st tarsometatarsal joint, the intermediate cuneonavicular joint and the subtalar joint ( posterior articular surface) under muscle force loading increased significantly (P<0. 05), and the change percentages were 132. 20% , 55. 41% , 30. 97% and 26. 87% , respectively. Conclusions In biomechanical experiment of foot and ankle specimens, muscle force loading has a significant effect on contact force, peak pressure and contact area of each foot joint, especially the forefoot.Therefore, it is necessary to consider the effect of muscle force loading on stress of foot and ankle in the study ofrelated in vitro specimens