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.

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.

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.

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.

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.

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.

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.

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.

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.

Morphological analysis of thoracic pedicle of 12-15-year-old idiopathic scoliosis and normal spine in northern Shaanxi province / 解剖学报

Objective To study the anatomical structure of normal and scoliotic thoracic vertebrae in adolescents aged 12-15 years in Northern Shanxi Province, to provide detailed information for pedicle screw placement, and to provide data references for screw size design. Methods Totally 120 cases of normal thoracolumbar CT of 120 adolescents aged 12 to 15 years and 30 cases of adolescent idiopathic scoliosis were collected in Northern Shaanxi Province. The raw data of thoracolumbar tomographic images scanned continuously were imported into Mimics16. 0 software for analysis and measurement in DICOM format. Measurement indicators: pedicle width, pedicle height, pedicle length, transverse diameter of spinal canal, longitudinal diameter of spinal canal, transverse pedicle angle,maximum transverse pedicle angle, sagittal pedicle angle and pedicle area. Results Pedicle width:12-13 years old, T

Effects of posterior pedicle screw internal fixation on early Cage subsidence after oblique lateral lumbar interbody fusion / 西安交通大学学报(医学版)

【Objective】 To investigate the effects of one-stage additional posterior pedicle screws （PPS） internal fixation on early Cage subsidence after oblique lateral interbody fusion （OLIF）. 【Methods】 We made a retrospective analysis of 118 patients with lumbar degenerative diseases treated with OLIF at the Department of Orthopedics， Sir Run Run Shaw Hospital， School of Medicine， Zhejiang University， from January 2016 to December 2019. We divided the patients into OLIF stand-alone group （58 ones） and OLIF with PPS fixation group （60 ones） according to the surgical procedure. All the patients had preoperative frontal and lateral radiographs of the lumbar spine， and CT and MR scans were performed. The clinical outcomes and reoperation rates of the two groups were compared at immediate postoperative follow-up and at 1， 3， 6 and 12 months. X-ray and CT examinations were performed to assess Cage subsidence in both groups at each postoperative follow-up. 【Results】 There was no statistical difference between the two groups in baseline data and surgical segmentation. Of the 118 patients with 141 discs who underwent OLIF surgery， 58 patients with 68 discs received OLIF stand-alone surgery and 60 ones with 73 discs received OLIF with PPS fixation. There were no significant differences in intraoperative bleeding， complications， or postoperative clinical outcomes between the two groups （P>0.05）， and the Cage subsidence rate was 22.4% in OLIF stand-alone group and 5% in OLIF with PPS fixation group， with significant difference between the two groups （P<0.01）. 【Conclusion】 Both OLIF stand-alone and OLIF additional PPS fixation can achieve good early clinical outcomes， and first-stage additional PPS fixation can significantly reduce the occurrence of Cage subsidence in the early postoperative period after OLIF.

Clinical effects of treatment of single-segment lumbar tuberculosis by oblique lateral interbody fusion and percutaneous pedicle screw fixation / 西安交通大学学报(医学版)

【Objective】 To investigate the clinical effects of treatment of single-segment lumbar tuberculosis by oblique lateral interbody fusion with autologous iliac bone and percutaneous pedicle screw fixation. 【Methods】 We collected the clinical data of 47 patients with lumbar tuberculosis treated in The First Affiliated Hospital of Xi’an Jiaotong University from March 2017 to January 2020. Among them， 22 patients underwent oblique lateral interbody fusion with autologous iliac bone and percutaneous pedicle screw fixation （minimally invasive group） and 25 patients underwent open surgery combined anterior-debridement and posterior-fixation （control group）. The related data were collected， including gender， sex， body mass index （BMI）， systemic symptoms of tuberculosis， operation duration， intraoperative bleeding， postoperative drainage， hospital stay， complications， visual analogue score （VAS）， erythrocyte sedimentation rate （ESR）， and Oswestry disability index （ODI）. 【Results】 Baseline clinical characteristics did not significantly differ between the two groups （P>0.05）. Compared with control group， the minimally invasive group had shorter operation duration ［（188.64±18.59） min vs. （201.60±22.67） min］， less intraoperative blood loss ［（118.64±22.95） mL vs. （553.60±100.54） mL］， less postoperative drainage ［（134.55±36.48） mL vs. （291.20±61.53） mL］， and shorter hospitalization time ［（12.86±2.17） d vs. （15.80±3.03） d］ （all P0.05）. Compared with the preoperative ones， ESR， VAS score and ODI score significantly decreased and Cobb angle significantly increased in both groups （all P0.05）. 【Conclusion】 Both minimally invasive technique and open surgery can achieve excellent clinical results， but the minimally invasive technique can reduce the surgical trauma and shorten the hospitalization time.

Determining the accuracy of lumbar 4/5 pedicle screw entry point based on digital three-dimensional technology / 西安交通大学学报(医学版)

【Objective】 To establish a digital model of lumbar 4 and lumbar 5 vertebral bodies through three-dimensional imaging technology so as to explore the precise placement of pedicle screws during the lumbar posterior internal fixation operation. 【Methods】 CT scan image data set of lumbar spine included six specimens. Then lumbar modeling was produced using Mimics software， implanting pedicle screws was simulated with the computer to determine the reliability of pedicle screw for herringbone crest method， Weinstein method， and Magerl method. 【Results】 This study included six specimens （4 males and 2 females）， with an average age of 42.83 years. The distance from the right Magerl entry point to the actual entry point of the lumbar 4 vertebrae was significantly greater than that of the left side. The distance from the left herringbone crest entry point of lumbar 4 vertebrae to the actual entry point was significantly greater than Weinstein method and Magerl method （PMagerl abduction angle > Weinstein abduction angle > herringbone abduction angle. The distances of true-Weinstein and true-herringbone ridges on the left side of lumbar 5 vertebrae were significantly greater than those on the right side （P=0.002 and P=0.004）， and the Weinstein abduction angle on the right side of lumbar 5 vertebrae was greater than that on the left side （P=0.003）. For the left and right sides of lumbar 5 vertebrae， the distance from herringbone crest entry point to the actual entry point was significantly greater than that of Weinstein method and Magerl method （P Magerl abduction angle > Weinstein abduction angle > herringbone abduction angle. 【Conclusion】 Both Weinstein entry point and Magerl entry point for lumbar 4 and lumbar 5 vertebra are close to the real entry point. The Weinstein abduction angle and Magerl abduction angle of lumbar 4 and lumbar 5 vertebrae have minor differences compared with real abduction angle. Therefore， it is recommended that Weinstein method is the preferred choice for lumbar 4 pedicle screw placement， while Weinstein method or Magerl method is the preferred choice for lumbar 5 pedicle screw placement.

Suspension exercise training can improve walking and balance after thoracolumbar fracture and spinal cord injury / 中华物理医学与康复杂志

Objective:To explore the effect of suspension exercise training (SET) on the lumbar function and balance ability of patients with thoracolumbar fracture and spinal cord injury.Methods:Totally 64 patients with thoracolumbar fracture and spinalcord injury were randomly divided into a control group and an observation group, each of 32. Both groups received pedicle screw reduction with internal fixation and spinal dome decompression, followed by routine post-operative rehabilitation. In addition, the observation group performed double bridge and single leg suspension training and pelvic lift training. Everyone′s walking ability, spinal nerve functionality and balance were evaluated 3 days after the operation and 2 months after the training. Stride frequency, stride length and walking speed were observed. American Spinal Injury Association (ASIA) nerve function classifications were assigned. The trajectory length, trajectory included area and movement deviation of each subject′s center of gravity (CG) was recorded.Results:The average stride frequency, step length and walking speed of the observation group had all improved significantly after the intervention, and were significantly better than the control group′s averages at that point. This was also true of the proportion in ASIA neurological function grade D (65.63%), CG trajectory length and area, and the Romberg rate of deviation along the X-axis and Y-axis of the CG.Conclusion:SET training after pedicle screw reduction and internal fixation and spinal dome decompression can significantly improve the spinal nerve functioning of persons after a thoracolumbar fracture with incomplete spinal cord injury. It enhances their balance and walking ability. Such therapy is worthy of clinical promotion and application.

Analysis on influencing factors of vertebral body height reloss after pedicle screw fixation of thoracolumbar fracture / 中华创伤杂志

Objective:To investigate the related factors of vertebral body height reloss after pedicle screw fixation of thoracolumbar fracture and to determe the optimum prediction point.Methods:A retrospective case control study was made on 215 patients with thoracolumbar fracture admitted to Second Affiliated Hospital of Soochow University from January 2010 to December 2017. There were 155 males and 60 females，aged 21-80 years［（48.6±10.4）years］. According to Denis fracture classification，there were 73 patients with compression fractures（type A in 15 patients，type B in 51，type C in 7），135 burst fractures（type A in 28 patients，type B in 87，type C in 20）and flexion distraction fractures（type A in 4，type B in 2，type C in 1）. All patients were treated by pedicle screw fixation. Follow-up lasted for 12- 48 months［（23.8±8.2）months］. Vertebral body height loss occurred in 86 patients（loss group），but did not in 129 patients（non-loss group）. The two groups were compared concerning sex，age，osteoporosis self-assessment tool for Asians（OSTA），body mass index（BMI），fracture types，number of fractured vertebrae，preoperative sagittal Cobb angle，preoperative degree of vertebral compression，number of screws placed in injured vertebrae，extent of vertebral reset and other related factors. Univariate analysis was used to identify the correlation of those factors with vertebral body height reloss. Multivariate Logistic regression analysis was performed to identify the independent factors for the height reloss with the receiver operating characteristic curve（ROC）and area under the curve（AUC）calculated to evaluate the optimum point in prediction of vertebral height reloss.Results:The two groups showed no significant differences in sex，age，BMI，fracture types，number of injured vertebrae，preoperative sagittal Cobb angle and number of screws placed in injured vertebrae（ P>0.05），but the differences were statistically significant in OSTA，preoperative degree of vertebral compression and extent of vertebral reset（ P<0.05）. According to the univariate analysis，OSTA，preoperative degree of vertebral compression and extent of vertebral reset were significantly correlated with the occurrence of vertebral body height reloss（ P<0.05）. According to the multivariate Logistic regression，OSTA（ OR=1.109，95% CI 0.527-0.685， P<0.05）and preoperative degree of vertebral compression（ OR =0.038，95% CI 0.539-0.689， P<0.05）were significantly related to vertebral body height reloss. The AUC relating OSTA and preoperative degree of vertebral compression to vertebral body height reloss was 0.604 and 0.614，respectively. The optimum prediction point of OSTA and preoperative degree of vertebral compression for vertebral body height reloss was 1.9 and 31.3%，respectively. Conclusions:OSTA and the preoperative degree of vertebral compression are independent risk factors for vertebral body height reloss. OSTA≤1.9 or preoperative degree of vertebral compression ≥31.3% indicates a significantly higher risk of postoperative vertebral body height reloss.

Efficacy of posterior pedicle screw reduction and internal fixation of atlantoaxial fractures: comparison between O-arm navigation assisted and free-hand techniques / 中华创伤杂志

Objective:To investigate the effect of O-arm navigation assisted posterior pedicle screw reduction and internal fixation of atlantoaxial fractures.Methods:A retrospective case-control study was conducted to analyze 37 patients with atlantoaxial fractures admitted to Third Hospital of Hebei Medical University from January 2016 to June 2018, including 22 males and 15 females, aged from 29 to 68 years [(50.9±9.8)years]. The posterior pedicle screw reduction and internal fixation was performed under O-arm navigation system (navigation group, n=24), and using free-hand technique (free-hand group, n=13). The operation time and blood loss were compared between the two groups. The Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) were used to evaluate the clinical efficacy before operation, 7 days operation and at the last follow-up. The complications were detected. A total of 86 screws were placed in navigation group (Neo grade 0: 83 screws, grade 1: 2 screws, grade 2: 1 screw ), and 44 screws were inserted in free-hand group (Neo grade 0: 36 screws, grade 1: 5 screws, grade 2: 2 screws, grade 3: 1 screw)( P<0.05). Classification of screw positions proposed by Neo et al was used to evaluate the position relationship between the screw and the bone cortex and the incidence of screw penetration. Results:All patients were followed up 24-38 months [(27.7±4.0)months]. The operation time in navigation group was (189.8±35.4)minutes, significantly shorter than (221.5±48.6)minutes in free-hand group ( P<0.05). The bleeding volume in navigation group was 300.0 (250.0, 537.5)ml , significantly less than 500.0 (425.0, 625.0)ml in free-hand group ( P<0.05). Both groups showed significantly enhanced JOA and decreased NDI after operation and at last follow-up, compared with those before operation ( P<0.05). However, there was no significant difference in JOA and NDI between the two groups ( P>0.05). No severe complications such as neurovascular injury occurred during operation. The incidence of cortical penetration was 3% (3/86) in navigation group and 18% (8/44) in free-hand group ( P<0.05). Conclusions:In the process of posterior atlantoaxial pedicle screw placement, the application of O-arm navigation can significantly reduce the operation time and amount of bleeding, and enhance the accuracy of pedicle screw implantation.

Effect of modified Wiltse approach pedicle screw internal fixation combined with transpedicular bone grafting on the vertebral body and complications of senile osteoporotic vertebral compression fractures / 中华内分泌外科杂志

Objective:To investigate the effects of internal fixation with pedicle screw via modified Wiltse approach combined with transpedicular bone grafting on the vertebral body and complications of senile osteoporotic vertebral compression fractures (OVCF) .Methods:Ninety-four elderly patients with osteoporotic vertebral compression fractures who were admitted to Hangzhou Fuyang Traditional Chinese Medicine Orthopedics Hospital from Oct. 2018 to Oct. 2019 were selected as the research objects. The patients were divided into control group and observation group according to the random ball touch method. For 47 cases, the control group underwent posterior short-segment reduction and internal fixation combined with transpedicular bone grafting, and the observation group underwent modified Wiltse approach pedicle internal fixation combined with transpedicular bone grafting. The two groups were observed and compared in terms of surgery related indicators, the condition of the injured vertebrae, the recovery of the vertebral body, the length of hospitalization and fracture healing time, and the incidence of complications.Results:In comparison of the operation-related indexes between the two groups, the intraoperative blood loss, 3d postoperative visual analogue scale (VAS) score and operation time of the observation group were significantly lower, than those of the control group ( P<0.05) . In comparison of the condition of the injured vertebrae between the two groups, there was no significant difference in the ratio of the loss rate of the injured vertebrae Cobb angle, vertebral body sagittal plane index, and vertebral body height between the two groups before operation ( P>0.05) . The loss rates of Cobb angle and vertebral body height of the injured vertebrae in the two groups were lower than that before operation at 3 days after operation, and the sagittal index of the vertebral body was higher than before operation at 1 year after operation ( P<0.05) . The loss rate of Cobb angle and vertebral body height of the injured vertebral body in the observation group was significantly lower than that of the control group at 3 days postoperatively, and the vertebral body sagittal plane index was significantly higher than that of the control group at 1 year postoperatively ( P<0.05) . Comparing the recovery of injured vertebrae between the two groups, there was no statistically significant difference between the preoperative oswestry disability index (ODI) scores of the two groups ( P>0.05) , the improvement rate of Cobb angle and the recovery rate of vertebral body height in the observation group, ODI scores at 3 months after operation were significantly higher than those of the control group ( P<0.05) . The hospitalization time and fracture healing time of the observation group were significantly lower than those of the control group ( P<0.05) . The total incidence of complications in the observation group (4.26%) was significantly lower than the total incidence of complications in the control group (19.15%) ( P<0.05) . Conclusion:The combined use of internal fixation with pedicle screw via modified Wiltse approach combined with transpedicular bone grafting in treatment of elderly OVCF can reduce the amount of intraoperative blood loss, shorten the operation time and hospital stay and fracture healing time, improve the Cobb angle of the injured vertebra, promote the recovery of the height and function of the injured vertebra, and reduce the incidence of complications.

Biomechanical Study of Novel Articular Process Fixation System Combined with Unilateral Pedicle Screw Fixation / 医用生物力学

Objective To study the stability of lumbar spine after transforaminal lumbar interbody fusion (TLIF) surgery combined with a novel articular process fixation system (APFS). Methods Based on the validated finite element model of L3-S1 intact segment (Model A), TLIF surgery was simulated to establish bilateral pedicle screw TLIF model (Model B), right unilateral pedicle screw TLIF model (Model C), APFS combined with right pedicle screw fixation TLIF model (Model D). The range of motion (ROM) of the lumbar spine model and stress distributions on pedicle screws, APFS and interbody fusion cages under different working conditions were observed. Results The overall ROMs of Models B, C, and D under different working conditions were comparable, which were all smaller than those of the physiological model. Compared with Models B and C, the maximum compressive stress of the right pedicle screw and the interbody fusion cage in Model D was the smallest or between Models B and C under different working conditions. Model D had the largest peak stress of APFS and right pedicle screw during anterior flexion. Conclusions APFS combined with contralateral pedicle screw fixation can be used as a novel fixation method for TLIF surgery of lumbar spine.

Bone cement pedicle screw fixation and fusion in the treatment of degenerative spinal disease with osteoporosis: One-year follow-up / 中国组织工程研究

BACKGROUND: Even pedicle screw fixation system is commonly used in spinal surgery, elderly patients with high bone fragility lack of bone elasticity, insufficient holding power of pedicle screw. Thus, there is a risk of loosening and pulling out the screws, leading to failure of spine reduction and fixation. Thus, we need to explore new method to increase the stability of the pedicle screw system. OBJECTIVE: To explore the long-term effect of pedicle screw internal fixation with bone cement in the treatment of different types of lumbar degenerative diseases with osteoporosis. METHODS: Sixty patients suffering from degenerative spinal disease with the complication of osteoporosis were randomly assigned to control group and trial group (n=30 per group). Before adopting the treatment of bone cement pedicle screw fixation and fusion, all patients had taken pre-operation examination, X-ray, CT and MRI scan. The patients in the control group were treated with conventional pedicle screw technology, and those in the experimental group were treated with bone cement on the basis of the conventional pedicle screw technology. Visual analogue scale score and Oswestry disability index were compared between the two groups 1 day before surgery, 1 week, 6 months, and 1 year after surgery. Complications were observed after surgery to evaluate the effect of the operation. RESULTS AND CONCLUSION: (1) At 1 week, 6 months and 1 year after surgery, the visual analogue scale score and Oswestry disability index were significantly better than those of pre-operation (P < 0.05). Visual analogue scale score and Oswestry disability index were significantly lower at 6 months and 1 year after surgery than those 1 week after surgery (P < 0.05). Visual analogue scale score and Oswestry disability index were significantly lower at 1 year than those at 6 months after surgery (P < 0.05). (2) Visual analogue scale score and Oswestry disability index were better in the trial group than those in the control group at 6 months and 1 year after surgery (P < 0.05). (3) The incidence of internal fixation rod loosening was lower in the trial group than that in the control group. (4) It is concluded that bone cement pedicle screw fixation and fusion in the treatment of degenerative spinal disease with osteoporosis can effectively improve the clinical symptoms and reduce the occurrence of complications. It is safe and effective in clinical application, and the long-term treatment effect is acceptable.