Meta-analysis of cement-augmented pedicle screw for thoracolumbar degenerative diseases with osteoporosis / 中国组织工程研究

OBJECTIVE:Cement-augmentation pedicle screws have been widely used in spinal internal fixation surgery combined with osteoporosis in recent years,which can significantly improve the fixation strength,but compared with conventional methods,whether it has more advantages is still inconclusive of evidence-based medicine.To systematically evaluate the efficacy and safety of cement-augmented pedicle screw in the treatment of thoracolumbar degenerative diseases with osteoporosis. METHODS:Clinical controlled trials concerning the cement-augmented pedicle screw and the traditional pedicle screw placement for thoracolumbar degenerative diseases with osteoporosis were retrieved from the electronic databases such as CNKI,CBM,WanFang,VIP,PubMed,Cochrane Library,Web of Science and Embase.According to the unified criteria,we performed literature screening and quality evaluation.The meta-analysis was performed using RevMan 5.4 software. RESULTS:(1)Totally 20 articles were selected eventually,involving 2 randomized controlled studies and 18 retrospective cohort studies,totally 1 566 patients.Among them,789 cases were in the cement-augmented screw group and 777 cases in the conventional screw group.(2)Meta-analysis results showed that Japanese Orthopaedic Association score,intervertebral space height and fusion rate were higher in the cement-augmented screw group than those in the conventional screw group(MD=1.60,95%CI:1.14,2.07,P<0.000 01;MD=1.26,95%CI:0.62,1.90,P=0.000 1;OR=11.24,95%CI:2.86,44.14,P=0.000 5).Operation time was longer in the cement-augmented screw group than that in the conventional screw group(SMD=0.82,95%CI:0.42,1.23,P<0.000 1).Postoperative visual analog scale score,Oswestry dysfunction index score and incidence of screw loosening were lower in the cement-augmented screw group than those in the conventional screw group(MD=-0.50,95%CI:-0.78,-0.21,P=0.000 7;SMD=-0.49,95%CI:-0.88,-0.10,P=0.01;OR=0.08,95%CI:0.05,0.12,P<0.000 01).Hospitalization time,intraoperative blood loss,and postoperative drainage volume were not significantly different between the two groups(P>0.05). CONCLUSION:Compared with conventional pedicle screw placement,cement-augmented pedicle screw is more effective in the treatment of osteoporotic thoracolumbar degenerative disease by improving fusion rate and interbody height,reducing the incidence of screw loosening,and elevating long-term efficacy.

Morphological classification of CT reconstruction of the narrowest part of pediculoisthmic component / 中国组织工程研究

BACKGROUND:It has been suggested that CT multiplanar reconstruction should be performed prior to the placement of axial pedicle screws to determine the anatomy of the C2 pedicle in each patient,to design the appropriate screw locus and diameter,and to evaluate the feasibility of screw placement to reduce the incidence of surgery-related complications. OBJECTIVE:To evaluate the feasibility of axis pedicle screw placement by morphologic classification of pediculoisthmic component with CT multiplanar reconstruction. METHODS:The CT data of 200 patients(400 axial pedicle screws)with cervical spine were retrospectively studied by using Siemens Syngo.Via software.According to the direction of the axis of the pedicle,the CT multiplanar reconstruction positioning line was adjusted to reconstruct the sectional image of the narrowest part of the pediculoisthmic component.According to its morphological characteristics,the narrowest part of the pediculoisthmic component was divided into three types:type 1,"hook"type:Type 1a outer diameter width(a1)>0.4 cm,type 1b outer diameter width(a1)≤0.4 cm;type 2,"like circle/ellipse"type;type 3,"horizontal ellipse"type.The outer diameter width of the narrowest part of pediculoisthmic component(d1),medullary cavity width(d2),outer diameter height(a1),and medullary cavity height(a2)were compared among the three types,and the feasibility of pedicle screw placement of the three types was evaluated. RESULTS AND CONCLUSION:(1)A total of 400 axial pedicles included 269 cases of type 1,130 cases of type 2,and 1 case of type 3.(2)The mean external diameter height between types 1 and 2 was not significantly different(P>0.05).The mean medullary cavity height,mean outer diameter widths,and mean medullary cavity width were significantly different(P<0.001).There were 42 cases(15.6%)of type 1 and 0 cases(0.00%)of type 2 with mean external diameter width≤0.4 cm,and the difference was significant(P<0.001).There was only one case of type 3,whose external diameter height,medullary cavity height,outer diameter width and medullary cavity width were 1.20 cm,0.84 cm,0.64 cm and 0.31 cm,respectively.(3)These results confirm that axial pedicle screws can be safely inserted in patients with types 1a,2 and 3,which requires no further measurement and assessment.Pedicle screw insertion should be performed with caution in type 1b patients.Therefore,in type 1 patients,the width of the narrowest outer diameter of the pediculoisthmic component should be further measured to evaluate the feasibility of axial pedicle screw placement.

Uniaxial endoscopic intervertebral fusion combined with pedicle screw fixation in treatment of lumbar degenerative diseases / 中国组织工程研究

BACKGROUND:With the rapid development of minimally invasive spinal surgery and enhanced recovery after surgery,endoscopic intervertebral fusion techniques have gradually emerged and been widely used in clinical practice in recent years. OBJECTIVE:To analyze the early clinical efficacy of uniaxial spinal endoscopic intervertebral fusion combined with posterior percutaneous pedicle screw fixation in the treatment of lumbar degenerative diseases. METHODS:135 patients with lumbar degenerative diseases treated by uniaxial spinal endoscopic intervertebral fusion combined with posterior percutaneous pedicle screw fixation in the Suining Central Hospital from October 2020 to December 2021 were enrolled in this study.There were 59 males and 76 females,aged 47-79 years.The lower limb and lumbar pain was evaluated by visual analog scale and lumbar function was assessed by Oswestry disability index before the operation,1 week,1,and 6 months after the operation,and at the end of follow-up.The overall pain recovery of patients was evaluated by the scoring criteria for low back pain surgery of Spine Group of Chinese Orthopedic Association and the lumbar physiological curvature and intervertebral fusion were evaluated on lumbar lateral X-ray preoperatively and at the end of follow-up. RESULTS AND CONCLUSION:(1)The 135 patients were followed up for(17.8±3.0)months after surgery.There was 1 case of endplate injury,1 case of cerebrospinal fluid leakage,1 case of nerve root injury,1 case of intervertebral cage subsidence and displacement,1 case of chronic infection,and 1 case of pedicle screw rupture.The complication rate was 5.2%.(2)The lumbar visual analog scale score and Oswestry disability index significantly decreased in the waist and lower limbs at various time points postoperatively compared with those preoperatively in 135 patients(P<0.05).The scoring criteria for low back pain surgery of the Spine Group of the Chinese Orthopedic Association were significantly better at the last follow-up than that preoperatively in 135 patients(P<0.05).(3)At the last follow-up,there was no significant difference in physiological curvature of lumbar vertebra as compared with that preoperatively in 135 patients(P>0.05),with a fusion rate of 95.8%.(4)It is concluded that uniaxial spinal endoscopic intervertebral fusion combined with posterior percutaneous pedicle screw fixation in the treatment of lumbar degenerative diseases has shown satisfactory early clinical results and is a highly safe minimally invasive spinal surgery mode.

Subcutaneous endplate bone graft reduction combined with percutaneous pedicle screw fixation for A3+B2 thoracolumbar burst fractures / 中国组织工程研究

BACKGROUND:Bone grafting is one of the important steps in the treatment of thoracolumbar burst fractures.Because the fracture involves the spinal canal or is accompanied by spinal cord nerve damage,severe fracture bleeding and other factors,minimally invasive bone grafting for thoracolumbar burst fractures is restricted.At present,the minimally invasive treatment of thoracolumbar burst fractures is limited to percutaneous screw fixation under the tunnel.Minimally invasive percutaneous bone grafting of injured vertebrae is rarely reported,and percutaneous precise bone grafting under the endplate has not yet been reported. OBJECTIVE:To investigate the clinical effect of subcutaneous endplate bone graft support reduction combined with percutaneous pedicle screw short-segment fixation in the treatment of A3+B2 thoracolumbar burst fractures. METHODS:From June 2017 to December 2021,90 patients with A3+B2 type asymptomatic thoracolumbar burst fracture were randomly divided into 3 groups according to admission time.In group A,33 patients received the bone graft funnel accurately placed through the pedicle channel by percutaneous puncture under C-arm fluoroscopy,bone graft support reduction under the fracture endplate,percutaneous pedicle screw fixation.In group B,30 patients received multifissure intermuscular approach through pedicle bone graft support reduction combined with pedicle screw fixation.In group C,27 patients received percutaneous pedicle screw short-segment fixation under postural reduction.All patients were followed up for at least 18 months after surgery.The clinical data of the three groups,including preoperative,postoperative and last follow-up Cobb angle,anterior edge height ratio and visual analog scale pain score,were compared and analyzed. RESULTS AND CONCLUSION:(1)There were no significant differences in age,sex,injury segment and causative factors among the three groups(P>0.05).(2)All patients at follow-up had no neurological impairment,no obvious lumbar posterior deformity or intractable low back pain.(3)The operation time of group C was less than that of group A and group B(P<0.05).Intraoperative blood loss was less in group A and group C than in group B(P<0.05).(4)There were no significant differences in the anterior edge height ratio and Cobb angle among the three groups(P>0.05).Postoperative data in groups A and B were better than that in group C.At last follow-up,group A and group B outperformed group C(P<0.05).The height and Cobb angle of the vertebral body lost in the three groups were smaller in groups A and B than those in group C(P<0.05).(5)Visual analog scale pain score was better in groups A and C than that in group B after surgery(P<0.05).There was no significant difference in visual analog scale pain score among the three groups at last follow-up(P>0.05).(6)In group C,there was one case of loose internal fixation and displacement in 1 month after surgery,and the vertebral height was lost again with back pain,and after strict bed rest for 6 weeks,the vertebral height loss was not aggravated,the pain was relieved,and the internal fixation was removed after 1 year,and the height loss at the last follow-up was not aggravated.There were no cases of failure of internal fixation in groups A and B.(7)It is indicated that subcutaneous endplate bone graft support reduction combined with percutaneous pedicle screw short-segment fixation in the treatment of A3+B2 thoracolumbar burst fracture has the advantages of less trauma,less bleeding and light postoperative pain symptoms,and the effect of injury vertebral reduction and height maintenance is the same as the reduction through pedicle bone grafting support and short segment fixation with pedicle screws through the multifidus space approach.

Robot-assisted pedicle screw internal fixation in treatment of atlantoaxial dislocation / 中国组织工程研究

BACKGROUND:Atlantoaxial dislocation,because of its high difficulty and high risk of surgery,has been regarded as the"surgical restricted area"by the international orthopedic community.However,with the rapid development of intelligent digitization in orthopedics,robot-assisted navigation screw placement technology has been widely used in clinical practice,which significantly reduces the difficulty and risk of surgery and improves the safety of surgery.However,there are few reports on the application of this technique in the treatment of atlantoaxial dislocation. OBJECTIVE:To explore the application value of robot-assisted pedicle screw internal fixation in the treatment of atlantoaxial dislocation. METHODS:The medical records of five patients with atlantoaxial dislocation treated with C1-C2 pedicle screw fixation under robot-assisted navigation in Zhuhai Hospital of Guangdong Provincial Hospital of Chinese Medicine from October 2021 to July 2022 were retrospectively analyzed.Operation time,length of neck incision,blood loss,postoperative drainage volume,and length of hospital stay were recorded.Attention should be paid to cerebrospinal fluid leakage,vertebral artery injury,nerve injury,operative area infection and other complications.The visual analog scale score of neck pain,the spinal cord injury grade of the American Spinal Injury Association,the cervical spine score of the Japanese Orthopaedic Association,and the imaging indicators were collected before surgery and at the last follow-up.Screw placement accuracy was assessed. RESULTS AND CONCLUSION:(1)Five patients were successfully completed surgery,without vascular,nerve injury or other complications,and were followed up for 12-20 months.(2)A total of 20 cervical pedicle screws were placed in 5 patients,including 9 type A screws,10 type B screws,and 1 type C screw.The accuracy of screw placement was 95%.(3)At the last follow-up,the visual analog scale score was(0.80±0.71)points,which was significantly lower than that before operation(4.00±2.83)points;the Japanese Orthopaedic Association score was(14.80±0.84)points,which was significantly higher than that before operation(8.00±0.71)points.Anterior atlantodental interval decreased from(7.86±3.25)mm to(2.82±0.93)mm;space available of the spinal cord increased from(6.74±1.99)mm to(12.10±3.51)mm;cervicomedullary angle increased from(133.32±13.55)° to(153.44±9.53)°;clivus-canal angle increased from(128.02±9.92)° to(143.25±12.99)°.The results of the last follow-up indexes were improved compared with those before operation,and the differences were significant(all P<0.05).(4)Postoperative imaging follow-up showed that all patients had bone fusion in the bone graft area,and no internal fixation loosening,fracture or pull-out occurred.(5)This method can avoid relying on the doctor's experience and hand feeling,ensure the accuracy of upper cervical screw placement,reduce the risk of surgery,and obtain satisfactory results in mid-term follow-up.

Study on the accuracy of cervical pedicle screw placement assisted with improved 3D-printed drill guiding template / 中国脊柱脊髓杂志

Objectives:To explore the accuracy of pedicle screw placement assisted with improved 3D-print-ed drill guiding template in cervical spine.Methods:The clinical data of 60 patients undergone posterior cervical pedicle screw placement in our hospital between January 2016 and January 2023 were analyzed retro-spectively,including 30 males and 30 females with an average age of 17-84 years(58.7±13.8 years).The pa-tients were divided into guiding template group and free-hand group based on whether the guiding template was used to assist the placement of screws or not.The improved 3D-printed guiding template was used to assist cervical pedicle screw placement in the guiding template group(n=30),and the self-made angular-ruler was used in the free-hand group(n=30).There was no significant difference in age,gender ratio,and preoper-ative diagnosis between the two groups(P＞0.05).Cervical CT scan was performed at one week after surgery,and the accuracy of pedicle screw placement was evaluated according to the Kaneyama standard:Grade 0,the screw was completely in the pedicle;Grade 1,the size of screw penetrating the cortex＜50%of the screw diameter;Grade 2,the size of screw penetrating the cortex≥50%of the screw diameter but not com pletely out;Grade 3,the screw was completely on the outside of the pedicle.The accuracy of pedicle screw placement(ratio of grades 0 and 1)and complications such as vascular and nerve injury,incision infection,cerebrospinal fluid leakage,screw loosening and breakage caused by screw misplacement were recorded.Re-sults:A total of 152 pedicle screws were placed in the guiding template group,including 74 screws of grade 0,68 of grade 1,10 of grade 2 and 0 of grade 3,with an accuracy of screw placement of 93.4%.A total of 136 pedicle screws were placed in free-hand group,including 53 screws of grade 0,61 of grade 1,18 of grade 2 and 4 of grade 3,with an accuracy of screw placement of 83.8%.The accuracy of screw placement in the guiding template group was significantly higher than that in the free-hand group(P＜0.05).There were no related complications such as vascular and nerve injury,incision infection and cerebrospinal fluid leakage caused by misplacement of pedicle screws.The patients were followed up for 5-29 months(14.2±7.7months),and there were no complications such as screw loosening or breakage.Conclusions:Improved 3D-printed drill guiding template can improve the accuracy of pedicle screw placement in cervical spine.

Clinical efficacy of decompression under full-endoscope and percutaneous pedicle screw fixation in the treatment of single-level thoracolumbar burst fracture / 中国脊柱脊髓杂志

Objectives:To explore the safety and early effectiveness of decompression under full-endoscope and percutaneous pedicle screw fixation in the treatment of single-level thoracolumbar burst fractures.Methods:The clinical data of 9 patients with single-segment thoracolumbar burst fracture treated with spinal canal decompression under full-endoscope and percutaneous pedicle screw fixation from April 2021 to June 2022 in our hospital were analyzed retrospectively,including 7 males and 2 females.The age ranged from 23 to 61(39.3±9.1)years old.According to AO classification,there were 6 cases of type A,2 cases of type B and 1 case of type C.Fracture segments were T12 in 2 cases,L1 in 3 cases,L2 in 3 cases,and L3 in 1 case.According to the classification of American Spinal Injury Association(ASIA)grading,there were 2 cases of type C,2 cases of type D,and 5 cases of type E.The decompression and percutaneous pedicle screw fixation were operated through the same incision in the injured vertebrae for screw placing.The operation-related indexes and complications were recorded.The patients'low back pain was evaluated by visual analogue scale(VAS)score before operation,on 3rd day after operation and at the last follow-up.The sagittal Cobb angle,height ratio of vertebral anterior edge,and the rate of spinal canal occupation were measured on spinal X-ray and CT images,and the recovery of neurological function was evaluated at the last follow-up.Results:All 9 patients successfully completed the operation,and the operative time was 105-145min(1 12.4± 21.2min),bleeding volume was 50-110mL(83.9±19.6mL),and hospitalization time was 7-13d(9.1±1.3d).No serious complications such as wound infection,cerebrospinal fluid leakage,aggravated nerve injury occurred.The follow-up time was 6-13months(8.4±3.9 months),all the fractures healed successfully,and the healing time was 3-6 months(4.7±1.6 months).The VAS score of low back pain on the 3rd day after operation and at final follow-up significantly improved compared with that before operation(P＜0.05),and it was also significantly improved at the last follow-up compared with that on the 3rd day after operation(P＜0.05).The Cobb angle,anterior height ratio of injured vertebrae,and invasion rate of spinal canal were significantly improved compared with those before operation(P＜0.05),respectively,but there was no statistical difference between the last follow-up and postoperative 3d(P＞0.05).One patient recovered from grade C to grade D of ASIA classification,while another three patients with neurological injury recovered completely.Conclusions:Decompression under full-endoscope and percutaneous pedicle screw fixation through the same incision in the injured vertebrae for screw placement in the treatment of single-level thoracolumbar burst fractures can obtain effective nerve root and spinal canal decompression,with good correction and small operative trauma,which is a safe and effective option.

Clinical application of 3D-printed drill guiding template in pedicle screw insertion in subaxial cervical spine / 中国脊柱脊髓杂志

Objectives:To explore the safety and accuracy of subaxial cervical pedicle screw(CPS)insertion assisted with optimized 3D-printed drill guiding template(DGT).Methods:A retrospective study was conducted to analyze the clinical data of 42 patients aged 32-74 years(50.1±9.8 years)who underwent posterior cervi-cal pedicle screw intemal fixation between August 2016 and October 2022.The patients were followed up for 13-25 months(19.6±3.2 months).They were divided into two groups of guiding template group(n=22)and free-hand group(n=20)according to the method of pedicle screw insertion.In the guiding template group,the sub-axial CPSs insertions were assisted with 3D-printed DGT,designed individually for each patient based on the design scheme of an optimized pedicle drill guiding template,and the patients consisted of 12 males and 10 females,among which 6 patients were with cervical spine injury or spinal cord injury,9 were with ossifica-tion of posterior longitudinal ligament(OPLL),5 were with intraspinal tumor,and 2 were with cervical spondy-lotic myelopathy.In the free-hand group,the subaxial CPSs were inserted with free hand according to the cervical parameters such as pedicle angle and diameter on the CT images measured before operation,and the patients consisted of 10 males and 10 females,among which 4 patients were with cervical spine injury or spinal cord injury,10 with OPLL,5 with intraspinal tumor,and 1 with cervical spondylotic myelopathy.There were no significant differences in sex,age,disease,and preoperative visual analogue scale(VAS)score and Japanese Orthopaedic Association(JO A)score between the two groups(P＞0.05).The operative time,intraopera-tive blood loss,and postoperative 12 months of VAS and JOA scores were recorded and compared.CT scan was performed at 1 week after operation on cervical spine,and the accuracy of pedicle screw placement was evaluated in accordance with Kaneyama's evaluation method:Grade 0,screw was contained in the pedicle;Grade 1,screw penetrated pedicle＜50％of the screw diameter;Grade 2,screw penetrated pedicle＞50％of the screw diameter;Grade 3,screw completely penetrated the pedicle.Grades 0 and 1 were considered accurate placement,and grades 2 and 3 were considered misplacement.The perioperative complications were recorded for each patient in the two groups.Results:The operative time,intra-operative blood loss in guiding template group(102.2±16.1min,89.3±17.7mL)were statistically less than those in free-hand group(142.8±20.9min,133.3±34.0mL)(P＜0.01).A total of 216 CPSs were placed:118 in the guiding template group,including 90 screws of grade 0,22 screws of grade 1,5 screws of grade 2,1 screw of grade 3,with an accuracy rate of 94.9％(112/118);And 98 in the free-hand group,including 48 screws of grade 0,36 screws of grade 1,10 screws of grade 2,and 4 screws of grade 3,with an accuracy rate of 85.7％(84/98).The accuracy rate of pedicle screw insertion was significant higher in the guiding template group than that in the free-hand group(P＜0.05).No major neurovascular complications nor internal fixation loosening or breakages were observed in two groups of patients.At 12 months after operation,the VAS score in both groups was statistically less than that before operation(P＜0.01),and the JOA score in both groups was statistically more than that before opera-tion(P＜0.01),and there were no significant differences in VAS score and JOA score between groups,respec-tively(P＞0.05).Conclusions:The optimized design scheme of 3D-printed DGT is helpful in improving the ac-curacy and safety of subaxial CPS insertion.

Meta-analysis of clinical efficacy of robot-assisted pedicle screw placement for the treatment of thoracolumbar vertebral fractures / 中国医学装备

Objective:To analyze and compare the clinical efficacy of robot-assisted and conventional navigation-assisted percutaneous minimally invasive pedicle screw placement in the treatment of thoracolumbar fractures and to provide reference for clinical treatment decisions.Methods:A literature search was performed in China National Knowledge Infrastructure(CNKI),VIP,Wanfang and English databases PubMed and Web of science by using the keywords"vertebral pedicle screws,"and"robot"in Chinese and"robot"and"pedicle screws"in English.The search time in both Chinese and English was from the establishment of the database to December 2022.The relevant clinical studies on robot-assisted and traditional navigation-assisted percutaneous minimally invasive pedicle screw placement for the treatment of thoracolumbar cone fractures were collected.Cochrane Scale and Newcastle-Ottawa Scale(NOS)were used to evaluate the quality of literatures and meta-analysis was carried out.The clinical effects of robot-assisted and traditional navigation-assisted surgery was compared.Results:A total of 15 articles were included in the study.Compared with traditional navigation-assisted percutaneous minimally invasive pedicle screw placement,robotic-assisted surgery resulted in shorter operative time[WMD=-11.45,95% CI(-18.94～-3.95),P＜0.05],less intraoperative bleeding[WMD=-19.11,95% CI(-27.51～-10.70),P<0.001],higher screw placement accuracy[number of grade A nails:RR=1.20,95% CI(1.16～1.25),P<0.001;number of grade A+B nails:RR=1.09,95% CI(1.07～1.11),P<0.001],and fewer complications[RR=0.35,95% CI(0.13～0.93),P＜0.05].The difference in hospitalization time was not statistically significant(P>0.05).Conclusion:In percutaneous minimally invasive pedicle screw placement for the treatment of thoracolumbar fractures,robot-assisted surgery has advantages over navigation-assisted surgery in terms of operative time,intraoperative bleeding,placement accuracy and complications.

Morphometric study and anatomical variation with its incidence of foramina transversaria on the lower cervical vertebrae / Estudio morfométrico y variación anatómica con la incidencia de forámenes transversos en las vértebras cervicales inferiores

SUMMARY: Anatomical variation of the foramina transversaria (FT) is associated with vertebral neurovascular symptoms and can cause complications after lower spine surgery, especially cervical pedicle screw (CPS) insertion. FT variation has been documented and classified in various populations, as this information can help increase cervical stability in subaxial vertebral surgery. Although the morphometry of the upper cervical spine in Thai populations has been reported, there have yet been no studies examining the features of FT. The FT of dried cervical spines (C3-C7; left and right side; n = 107, male = 53 and female = 54) were examined for morphological variation, and their anteroposterior (AP) and transverse (T) diameters were measured using a digital vernier caliper. Morphometric data and variations were compared by sex and lateral side. It was that the C3-C6 FT in both sexes were round, and the C7 FT was elliptical with an oblique right side. FT diameters did not differ significantly by sex except for the AP diameters of C6-C7 and for T diameters of C4 and C7. The left AP diameters of C3-C6 were significantly longer than the right, as were the T diameters of C4 and C7 FT. Additionally, T diameter was significantly longer than that of the AP, except that of the left C6 in male spines, which did not differ from the AP. Most FT examined were round. These findings should be considered in the provisional diagnosis of vertebral neurovascular symptoms caused by FT variation as well as that of neurovascular damage after cervical pedicle screw placement.

La variación anatómica del foramen transverso (FT) se asocia con síntomas neurovasculares vertebrales y puede causar complicaciones después de la cirugía de columna cervical inferior, especialmente la inserción de tornillos pediculares cervicales (TPC). La variación del FT se ha documentado y clasificado en varias poblaciones, ya que esta información puede ayudar a aumentar la estabilidad cervical en la cirugía vertebral subaxial. Aunque se ha informado sobre la morfometría de la columna cervical superior en poblaciones tailandesas, aún no se han realizado estudios que examinen las características de FT. Se examinó la variación morfológica del FT de vértebras cervicales secas (C3-C7; lado izquierdo y derecho; n = 107, hombres = 53 y mujeres = 54), y se midieron sus diámetros anteroposterior (AP) y transverso (T) usando un pie de metro digital. Se compararon datos morfométricos y variaciones por sexo y lado. Los FT de C3-a C6 en ambos sexos eran redondos, y el FT C7 era elíptico con el lado derecho oblicuo. Los diámetros del FT no difirieron significativamente por sexo excepto para los diámetros AP de C6- C7 y para los diámetros transversos de C4 y C7. Los diámetros AP izquierdos de C3-C6 eran significativamente más largos que los del lado derecho, al igual que los diámetros transversos de C4 y C7. Además, el diámetro transverso fue significativamente mayor que el AP, excepto el C6 izquierdo en las vértebras de hombres, que no difirió del AP. La mayoría de los FT examinados eran redondos. Estos hallazgos deben ser considerados en el diagnóstico provisional de síntomas neurovasculares vertebrales causados por la variación del FT, así como en el de daño neurovascular tras la colocación de tornillos pediculares cervicales.

O-arm real-time guidance in cervical pedicle screw fixation / 中国骨伤

OBJECTIVE@#To explore the technical aspects of the accuracy of cervical pedicle screw placement with O-arm guidance.@*METHODS@#The clinical data of 21 patients who underwent cervical pedicle screw fixation by O-arm real-time guidance from December 2015 to January 2020 were analyzed retrospectively. There were 15 males and 6 females, aged from 29 to 76 years old with an average of (45.3±11.5) years. The postoperative CT scan was utilized to evaluate the placement of the pedicle screw and classified according to the Gertzbein and Robbins classification.@*RESULTS@#A total of 132 pedicle screws were implanted in 21 patients, 116 at C3-C6 and 16 at C1 and C2. According to Gertzbein & Robbins classification, the overall breach rates were found to be 11.36% (15/132) with 73.33% (11 screws) Grade B, 26.67% (4 screws) Grade C, and no Grade D or E screw breaches. There were no pedicle screw placement related complications at final follow-up.@*CONCLUSION@#The application of O-arm real-time guidance technology can make cervical pedicle screw placement reliable. High accuracy and better intra-operative control can increase surgeon's confidence in using cervical pedicle instrumentation. Considering the high-risk nature of anatomical area around cervical pedicle and the possibility of catastrophic complications, the spine surgeon should have sufficient surgical skills, experience, ensures stringent verification of the system, and never relies solely on the navigation system.

Analysis of the clinical effect of percutaneous pedicle screw fixation combined with transpedicular bone grafting in the treatment of thoracolumbar fracture / 中国骨伤

OBJECTIVE@#To investigate the clinical efficacy of percutaneous screw fixation combined with minimally invasive transpedicular bone grafting and non-bone grafting in the treatment of thoracolumbar fractures.@*METHODS@#From Janury 2021 to June 2022, 40 patients with thoracolumbar fracture were divided into the experimental group and the control group. There were 26 patients in the experimental group, including 21 males and 5 females with an aberage age of (47.3±12.3) years old, who underwent percutaneous pedicle screw fixation combined with transpedicular autogenous bone grafting. In the control group, 14 patients received percutaneous pedicle screw fixation only. including 7 makes and 7 females with an average age of (50.2±11.2) years old. The operative time, intraoperative blood loss, anterior height ratio of injured vertebrae, Cobb angle, visual analogue score (VAS), MacNab scores, loosening or broken of the implants. were compared and analyzed.@*RESULTS@#There was no significant difference in operation time, intraoperative blood loss, VAS and anterior height ratio of injured vertebrae between the two groups. Compared with the preoperative results, VAS and anterior height ratio of injured vertebrae were improved statistically(P<0.05). For Cobb angle of injured vertebra, there was no significant difference between the two groups before surgery (P=0.766). While at 1 week, 3 months and 12 months after surgery, there were statistically differences between the two groups (P values were 0.042, 0.007 and 0.039, respectively). The Cobb angle of injured vertebrae one year after operation was statistically decreased in both groups compared with that before surgery (P<0.001). One year after surgery, the excellent and good rate of Macnab scores was 96.15% in the experimental group and 92.86% in the control group, and there was no statistical differences between the two groups (P=0.648). There was one patient in the control group suffering superficial wound infection on the third day, which was cured by dressing change and anti-infection treatment. There were no postoperative screw loosening and broken in both groups.@*CONCLUSION@#The two surgical methods have the advantages of less trauma, less pain and quicker recovery, which can restore the height of the injured vertebra, reconstruct the spinal sequence and reduce the fracture of the vertebral body. Transpedicular autogenous bone grafting can increase the stability of the fractured vertebra and maintain the height of the vertebra better after surgery, thus reducing the possibility of complications such as kyphosis, screw loosening and broken.

Treatment of spinal burst fractures with pedicle screw fixation at high altitude area / 中国骨伤

OBJECTIVE@#According to the characteristics of spinal burst fractures in high-altitude areas and the local medical conditions, to explore the clinical efficacy of short-segment fixation with pedicle screws combined with screw placement in injured vertebrae in the treatment of thoracolumbar burst fractures.@*METHODS@#From August 2018 to December 2021, 12 patients with single-vertebral thoracolumbar burst fractures without neurological symptoms were treated with injured vertebral screw placement technique, including 7 males and 5 females;aged 29 to 54 years old, with an average of(42.50±7.95) years old;6 cases of traffic accident injury, 4 cases of high fall injury, 2 cases of heavy object injury;2 cases of T11, 4 cases of T12, 3 cases of L1, 2 cases of L2, and 1 case of L3. In the operation, screws were first placed in the upper and lower vertebrae of the fracture, pedicle screws were placed in the injured vertebra, and connecting rods were installed, and the fractured vertebral body was reset by positioning and distraction. Visual analogue scale (VAS) and Japanese Orthopedic Association (JOA) scoring were used to evaluate the changes in pain and quality of life of patients, and the kyphotic correction rate and correction loss rate of the injured segment were measured by X-ray.@*RESULTS@#All operations were successful without significant intraoperative complications. All 12 patients were followed up, the duration ranged from 9 to 27 months, with an mean of (17.75±5.79) months. VAS at 3 days after operation was significantly higher than that at admission (t=6.701, P=0.000). There was significant difference in JOA score between 9 months after operation and at admission (t=5.085, P=0.000). Three days after operation, Cobb angle was (4.42±1.16)°, and the correction rate was (82±5)% compared with (25.67±5.71)° at admission. Cobb angle was (5.08±1.24) °at 9 months after operation, with a corrected loss rate of (16±13)%. No loosening or breakage of internal fixation was found.@*CONCLUSION@#Under the high-altitude hypobaric and hypoxic environment, the effect of the operation should be ensured while reducing the trauma. The application of the technique of placing screws on the injured vertebra can effectively restore and maintain the height of the injured vertebra, with less bleeding and shorter fixed segments, which is an effective method.

Percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of spinal metastases / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effectiveness of percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of patients with spinal metastases.@*METHODS@#In the study, 12 patients of spinal metastases treated with percutaneous pedicle screw fixation combined expandable tubular retractor in our hospital were retrospectively reviewed between June 2017 and October 2019. Among the 12 patients, 9 were males and 3 were females; the median age was 62.5 years [(65.1±2.9) years]. The decompression segment of 7 patients was located at the lower thoracic spine (including 1 patient with incomplete paraplegia) and the decompression segment of 5 patients was located at the lumbar spine; Tomita score was 6.0±0.6. Perioperative data of the patients were reviewed. Visual analog scale (VAS score), Karnofsky score, and Eastern Cooperative Oncology Group (ECOG) score were compared before and after surgery. The patient's survival, adjuvant treatment, and internal fixation failure were observed in the follow-up period.@*RESULTS@#All the 12 patients had a successful operation with percuta-neous pedicle screw fixation combined expandable tubular retractor. The average operative time, blood loss, and blood transfused of the patients were (247.0±14.6) min, (804.2±222.3) mL and (500.0±100.0) mL, respectively. The average amount of drainage was (240.8±79.3) mL. Drainage tubes were pulled out early postoperative [(3.2±0.3) d], allowing early mobilization. The patients discharged (7.8±0.8) d postoperative. All the patients were followed up for 6-30 months, and the average overall survival time was (13.6±2.4) months. During the follow-up period, 2 patients experienced screw displacement, the internal fixation was stable after conservative treatment and no revision surgery was performed. The VAS of the patients was 7.1±0.2 before surgery, which decreased to 2.3±0.1 and 2.8±0.4 at 3 and 6 months after surgery (P < 0.05). The Karnofsky score of the patients was 59.2±1.9 before surgery, which increased to 75.0±1.9 and 74.2±3.1 at 3 and 6 months after surgery (P < 0.05). The ECOG of the patients was 2.3±0.2 before surgery, which decreased to 1.7±0.1 and 1.7±0.2 at 3 and 6 months after surgery (P < 0.05).@*CONCLUSION@#For selected patients with spinal metastases, minimally invasive surgical treatment of spinal metastases (percutaneous pedicle screw internal fixation combined with expandable tubular retractor) can effectively relieve the clinical symptoms and improve the quality of life, with satisfactory clinical outcome.

Biomechanical Comparison of Internal Fixation by Traditional and Cortical Bone Trajectory Pedicle Screw / 医用生物力学

Objective To compare the effects of cortical bone trajectory ( CBT) and traditional trajectory ( TT)pedicle screw internal fixation on the range of motion (ROM) and rod system stress of normal and osteoporotic(OP) spines. Methods The L3-S1 finite element models of normal and OP spines were established. The screwrod system with two kinds of trajectory was used for internal fixation of the L4-5 segment, so as to simulate sixphysiological loads, namely, flexion, extension, left / right bending, left / right rotation. The effects of two internalfixation methods on ROMs and maximum equivalent stress of screws in normal and OP spines were compared.Results For both bone conditions, CBT and TT significantly reduced ROM of the fixed segment (L4-5) and theentire segment of lower lumbar spine ( L3-S1). However, the ROM decline of CBT group was slightly smaller than that of TT group, and their ROMs were similar under flexion and extension, but the ROM differences were significant under lateral bending and axial rotation. In addition, for both the normal and OP spine models, themaximum equivalent stress of screws in CBT group was significantly higher than that in TT group. Compared withTT group, the screw stress of CBT group in normal spine model under flexion and extension, lateral bending,axial rotation was increased by 27% , 268% and 58% , respectively. However, when CBT technique was used atthe same time, the OP spine model had a smaller screw stress distribution than the normal spine model.Conclusions Compared with TT technique, CBT technique can achieve higher screw stress under OP conditionand reduce screw stress concentration under normal bone condition. In addition, CBT slightly increases ROMs of each segment, which is conducive to recovery of spinal physiological function after surgery. Lateral bending and axial rotation can produce negative mechanical effects, and these two physiological loads should be avoided.

Comparison of efficacy of O-arm assisted and free-hand pedicle screw placement in the treatment of AO type C thoracolumbar fracture / 中华创伤杂志

Objective:To compare the effect of O-arm assisted and free-hand pedicle screw placement in the treatment of AO type C thoracolumbar fracture.Methods:A retrospective cohort study was used to analyze the clinical data of 34 patients with type C thoracolumbar fracture admitted to Henan Provincial People′s Hospital from January 2018 to June 2021, including 23 males and 11 females; aged 42-63 years [(50.4±7.4)years]. The fracture was located at T 11 in 4 patients, T 12 in 10, L 1 in 12, L 2 in 6, T 11~12/L 1 in 1 and T 12/L 1 in 1. Posterior reduction and internal fixation was carried out for all patients, of whom 18 were treated with O-arm assisted pedicle screw placement (navigation group) and 16 with free-hand pedicle screw placement (free-hand group). The operation time, single screw placement time, intraoperative bleeding volume, operation mode and screw placement accuracy were compared between the two groups. The kyphotic Cobb angle, visual analogue score (VAS) and American Spinal Injury Association (ASIA) score were compared between the two groups before operation, at 1 week after operation, at 3 months after operation and at the last follow-up. Postoperative complications were observed. Results:All patients were followed up for 12-29 months [(16.8±6.1)months]. There was no significant difference between the two groups in the operation time, intraoperative bleeding volume and operation mode (all P>0.05). The single screw placement time was (9.4±1.6)minutes in navigation group, but was (10.8±1.5)minutes in free-hand group ( P<0.05). The screw placement accuracy was 97.4% in navigation group, but was 81.5% in free-hand group ( P<0.01). The kyphotic Cobb angle and VAS had no significant differences between the two groups before operation (all P>0.05). The kyphotic Cobb angle in navigation group and free-hand group was (4.3±1.1)° and (5.9±1.1)° at 1 week after operation, (4.4±1.2)° and (5.7±1.3)° at 3 months after operation, and (4.4±1.2)° and (6.8±0.9)° at the last follow-up, decreased significantly from that before operation [(21.8±3.1)°, (22.2±3.2)°] (all P<0.01). The kyphotic Cobb angle in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The VAS in navigation group and free-hand group was (3.2±0.7)points and (4.1±0.7)points at 1 week after operation, (2.4±0.6)points and (3.0±0.8)points at 3 months after operation, and (1.8±0.9)points and (2.6±0.7)points at the last follow-up, decreased significantly from that before operation [(8.4±0.8)points, (8.3±0.9)points] (all P<0.01). The VAS in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The ASIA score showed no significant difference within and between the two groups before operation, at 1 week, 3 months after operation and at the last follow-up (all P>0.05). Postoperative incision infection occurred in 1 patient in both groups ( P>0.05). Implant failure such as loosening or displacement was not observed in navigation group, and only occurred in 2 patients in free-hand group ( P>0.05). Conclusion:Compared with free-hand pedicle screw placement, O-arm assisted pedicle screw placement in the treatment of AO type C thoracolumbar fracture has advantages of rapid and accurate screw placement, good reduction and notable pain relief.

Clinical application of percutaneous pedicle screw placement guided by ultrasound volume navigation combined with X-ray fluoroscopy: a prospective randomized controlled study / 中国修复重建外科杂志

OBJECTIVE@#To explore the feasibility and accuracy of ultrasound volume navigation (UVN) combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation through a prospective randomized controlled study.@*METHODS@#Patients with thoracic and lumbar vertebral fractures scheduled for percutaneous pedicle screw fixation between January 2022 and January 2023 were enrolled. Among them, 60 patients met the selection criteria and were included in the study. There were 28 males and 32 females, with an average age of 49.5 years (range, 29-60 years). The cause of injury included 20 cases of traffic accidents, 21 cases of falls, 17 cases of slips, and 2 cases of heavy object impact. The interval from injury to hospital admission ranged from 1 to 5 days (mean, 1.57 days). The fracture located at T 12 in 15 cases, L 1 in 20 cases, L 2 in 19 cases, and L 3 in 6 cases. The study used each patient as their own control, randomly guiding pedicle screw implantation using UVN combined with X-ray fluoroscopy on one side of the vertebral body and the adjacent segment (trial group), while the other side was implanted under X-ray fluoroscopy (control group). A total of 4 screws and 2 rods were implanted in each patient. The implantation time and fluoroscopy frequency during implantation of each screw, angle deviation and distance deviation between actual and preoperative planned trajectory by imaging examination, and the occurrence of zygapophysial joint invasion were recorded.@*RESULTS@#In terms of screw implantation time, fluoroscopy frequency, angle deviation, distance deviation, and incidence of zygapophysial joint invasion, the trial group showed superior results compared to the control group, and the differences were significant ( P<0.05).@*CONCLUSION@#UVN combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation can yreduce screw implantation time, adjust dynamically, reduce operational difficulty, and reduce radiation damage.

Comparison of clinical efficacies between cortical bone trajectory screw and pedicle screw fixation techniques under robot-assisted technology in posterior lumbar short-segment decompression and fu-sion / 中国脊柱脊髓杂志

Objectives:To compare the clinical efficacy between robot-assisted cortical bone trajectory screw(RCBTS)and robot-assisted pedicle screw(RPS)for patients with lumbar spinal stenosis(LSS)undergoing sin-gle-level decompression and fusion.Methods:In this retrospective cohort study,LSS patients who underwent robot-assisted single-level decompression and fusion in Beijing Shijitan Hospital between June 2020 and June 2022 were reviewed.A total of 99 patients were included and divided into RCBTS group of 41 patients and RPS group of 58 patients.There were 59 males and 40 females,with an average age of 67.07±4.65 years old.The incision length,operative time,intraoperative blood loss,24h postoperative drainage,and postopera-tive hospital stay were compared between groups.The Japanese Orthopaedic Association(JOA)score and visual analogue scale(VAS)of low back pain were compared at 3d,3 months and 6 months after operation,and the fixed effects of JOA score and VAS score changes were tested.The screw positions were graded according to the Gertzbein-Robbins method.The accuracy of screw placement of the two surgical methods was evaluated by reviewing the postoperative imaging data.The perioperative and postoperative 3 months of complications were compared between the two groups.Results:There were no significant differences in baseline data be-tween the two groups(P＜0.05).Comparing with the RPS group,the RCBTS group was shorter in operative time(134.39±22.23min vs 152.93±19.10min,P＜0.001),smaller in incision length(64.93±3.71mm vs 78.84±3.82mm,P＜0.001),less in intraoperative blood loss(155.61±37.15mL vs 172.41±43.22mL,P=0.001)and postoperative drainage within 24h(83.66±21.54mL vs 101.21±29.80mL,P=0.002),and shorter in postoperative hospital stay(4.90±1.26d vs 6.26±1.66d,P＜0.001),with statistical significance.There was no significant difference in JOA score and VAS score changes between the two groups at each time point(P＞0.05).The fixed effect test showed that time was a fixed effect of JOA and VAS score changes(P＜0.001).The RCBTS group was no sig-nificantly different from the RPS group in the accuracy of screw placement(grade A:152/164 vs 211/232,P=0.538;grade B:9/164 vs 15/232,P=0.688;grade C:3/164 vs 6/232,P=0.619),the rate of clinically accept-able screw placement(161/164 vs 226/232,P=0.619),the rate of bad screw placement(3/164 vs 6/232,P=0.619),and the incidence of postoperative complications(only 1 patient in the RCBTS group developed delayed wound healing)(P＞0.05).Conclusions:Compared with RPS,RCBTS has significant advantages in operative time,incision length,intraoperative blood loss,volume of postoperative drainage,and postoperative hospital stay.However,there is no significant difference between the two groups in terms of postoperative functional recovery and alleviation in low back pain.

Morphometric Assessment of Pedicles of Indian Adult Lumbar Vertebrae: A Cross Sectional Study

Introduction: Lumbar vertebral column is exposed to various kinds of stress during locomotion. In erect posture weight transmitted through posterior part including pedicles. This causes deformities of this region as the age advances in many individuals. Proper correction of deformity is challenging. There have been advances in spinal fusion procedures and interspinous implantation of devices including pedicle screws. Use of unsuitable dimensions of screw may cause problem of destruction of pedicle. Correct metricular data of pedicle is necessary for choice of appropriate screw size. Aims and Objectives: 1) To measure the various dimensions in Indian adult human lumbar vertebral pedicles. 2) To prepare data of lumbar pedicles useful in various surgical procedures. Material and Methods: A Cross-sectional study was done on 45 dry, fully ossified human lumbar vertebral sets. The bones were grouped into typical (L1 to L4) and atypical (L5) lumbar vertebrae. The dimensions measured included pedicle length, height, thickness, axial length, transverse and sagittal angles. ‘Digital Vernier Caliper’ and Protractor were used. The data was analyzed statistically. Results: The mean length, height and thickness of typical vertebral pedicles increases gradually. In atypical (L5), pedicle thickness suddenly increases. The transverse angle of pedicle elevated gradually from L1 to L4 but at L5, it abruptly increased. Conclusions: The study reported significant differences in several dimensions of pedicles of typical as well as atypical lumbar vertebrae. These differences should be considered by neurosurgeons.

The Influence of Thread Tap Mismatch on Pedicle Screw Pullout Strength / A influência da incompatibilidade do macho de rosca na resistência à extração do parafuso pedicular

Abstract Objective We aimed to study the "in vitro" pullout strength of SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct Screw (DSG Screw, SpineGuard Inc, Boulder, Colorado, USA), a screw designed to be inserted using a direct insertion technique. Methods Dynamic Surgical Guidance Screws of 5.5 and 6.5 mm were introduced into polyurethane blocks with a density of 10 PCF (0,16g/cm3). According to the experimental group, screws were inserted without pilot hole, with pilot without tapping, undertapping and line-to-line tapping. Screw pullout tests were performed using a universal test machine after screw insertion into polyurethane blocks. Results Screws inserted directly into the polyurethane blocks without pilot hole and tapping showed a statistically higher pullout strength. Insertion of the screw without tapping or with undertapping increases the pullout screw strength compared with lineto-line tapping. Conclusion Dynamic Surgical Guidance Screw showed the highest pullout strength after its insertion without pilot hole and tapping.

Resumo Objetivo Nosso objetivo foi estudar a resistência à extração "in vitro" do parafuso SpineGuard/Zavation Dynamic Surgical Guidance Z-Direct (Parafuso DSG Guia Cirúrgico Dinâmico, SpineGuard Inc, Boulder, Colorado, USA), um parafuso projetado para ser inserido utilizando a técnica de inserção direta. Métodos Os parafusos DSG de 5,5 e 6,5 mm foram introduzidos em blocos de poliuretano com densidade de 10 PCF (0,16g/cm3). De acordo com o grupo experimental, os parafusos foram inseridos sem um orifício piloto, com um orifício piloto sem o macheamento, com macheamento e com macheamento linha a linha. Os testes de extração do parafuso foram realizados em uma máquina de teste universal, após a inserção do parafuso em blocos de poliuretano. Resultados Os parafusos inseridos diretamente nos blocos de poliuretano sem o orifício piloto e o macheamento mostraram uma resistência à extração estatisticamente maior. A inserção do parafuso sem o macheamento ou com o macho de menor diâmetro aumenta a resistência à extração do parafuso em comparação com o macheamento linha a linha. Conclusão O parafuso DSG apresentou a maior resistência à extração após a inserção sem o orifício piloto e o macheamento.