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.

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.

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.

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.

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.

Comparison of Percutaneous versus Open Pedicle Screw Fixation for Treating Unstable Thoracolumbar Fractures

PURPOSE: This study compared the clinical and radiological results between two groups of patients with percutaneous fixation or conventional fixation after hardware removal.MATERIALS AND METHODS: The study analyzed 68 patients (43 open fixation and 43 percutaneous screw fixation [PSF] 25) who had undergone fixation for unstable thoracolumbar fractures. The radiologic results were obtained using the lateral radiographs taken before and after the fixation and at the time of hardware removal. The clinical results included the time of operation, blood loss, time to ambulation, duration of the hospital stay and the visual analogue scale.RESULTS: The percutaneous pedicle screw fixation (PPSF) group showed better results than did the conventional posterior fixation (CPF) group (p<0.05) in regard to the perioperative data such as operation time, blood loss, and duration of the hospital stay. There were no significant differences in wedge angle, local kyphotic angle, and the ΔKyphotic angle on the postoperative plane radiographs between the two groups (p>0.05). There were no significant differences in the wedge angle and local kyphotic angle after implant removal (p>0.05) between the two groups as well. However, there were significant differences in the segmental montion angle (p<0.001), and the PPSF group showed a larger segmental motion angle than did the CPF group (CPF 1.7°±1.2° vs PPSF 5.9°±3.2°, respectively).CONCLUSION: For the treatment of unstable thoracolumbar fractures, the PPSF technique could achieve better clinical results and an improved segmental motion angle after implant removal within a year than that of the conventional fixation method.

Comparison of the short-segment and long-segment cement-augmented pedicle screw fixation for osteoporotic thoracolumbar fracture: A finite element study / 中国组织工程研究

BACKGROUND: Pedicle screw fixation combined with cement-augmented is an effective method for the treatment of severe osteoporotic vertebral fractures, but there is no uniform standard. The range of fixed segments is one of the focus of clinical controversy. OBJECTIVE: To establish a three-dimensional finite element model of the short-segment and long-segment cement-augmented pedicle screw fixation for osteoporotic thoracolumbar fracture, and to analyze the biomechanical characteristics of adjacent segment structures, fractured vertebral bodies and internal fixation devices. METHODS: The T 9 -L 5 segment of a volunteer without obvious degenerative disease was selected for CT scan. The CT images of Dicom format were obtained, and the engineering software was imported to establish a finite element geometric model to simulate the thoracolumbar fracture and the short-segment and long-segment cement-augmented pedicle screw fixation models. The relevant material parameters were set and the biomechanical characteristics of the two groups were compared and analyzed. RESULTS AND CONCLUSION: (1) The stress on the vertebrae was mainly concentrated on the periphery of the vertebral body and the small facet of the attachment. In the four directions flexion, extension, left-sided and right-sided curvature, the maximum stress of the proximal and distal adjacent vertebrae in the long-segment group was greater than that in the short-segment group. The stress of the intervertebral disc was mainly concentrated in the peripheral annulus. The maximum stress of the proximal and distal adjacent intervertebral discs was greater in the short -segment than in the long-segment, but the high stress area of the long-segment was larger than that of the short-segment. Therefore, long-segment fixation might accelerate the degeneration of adjacent segments.(2) The vertebral bodies of the long-segment group and the short-segment group were displaced to different extents, and the displacements in the left and right directions were the most obvious. In the six movement directions, the displacement and maximum stress of the injured segment of the short-segment group were greater than those of the long-segment group. So the long-segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short- segment group.and the displacements in the left and right directions were the most obvious. In the six movement directions, the displacement and maximum stress of the injured segment of the short-segment group were greater than those of the long-segment group. So the long- segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group.and the displacements in the left and right directions were the most obvious. In the six movement directions, the displacement and maximum stress of the injured segment of the short-segment group were greater than those of the long-segment group. So the long- segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group.So the long-segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group. So the long-segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group.

Computer navigation-assisted surgical treatment with osteotomy for upper thoracic kyphosis / 中国组织工程研究

BACKGROUND: The biomechanical characteristics of kyphosis of the upper thoracic vertebra are unique. Decompression and internal fixation are relatively difficult. Previous relevant studies and case reports are few, and there is a lack of research on correction of kyphosis of the upper thoracic section with the assistance of computer navigation. OBJECTIVE: To explore the clinical effect of computer navigation-assisted surgical treatment of upper thoracic kyphosis by screws and osteotomy. METHODS: Totally 18 patients with kyphotic deformity of the spine (T1-T4) were admitted in Beijing Jishuitan Hospital from June 2011 to June 2018, including 11 males and 7 females, aged 12 to 59 years. They were all treated with computer-assisted surgical treatment with PSO osteotomy. Local Cobb angle of the upper thoracic kyphosis was determined during final follow-up. Cervical visual analogue scale, Nurick grades, EMS scores and satisfaction of the surgery were evaluated. This study was approved by the Ethics Committee of Beijing Jishuitan Hospital (approval No. 201709-23). RESULTS AND CONCLUSION: (1) A total of 18 patients were followed up for 6-90 months at an average time of (33. 73±35. 33) months. (2) The local Cobb angle of 18 patients at the last follow-up was significantly improved [(47. 32±9. 92)°, (24. 01 ±7. 64)°, P < 0. 001]. Cervical visual analogue scale score at the last follow-up was significantly lower than that before surgery (3. 64±2. 16, 0. 73±1. 01, P< 0. 001). Nurick score at the last follow-up was significantly lower than that before surgery (2. 91 ±0. 94, 0. 82±1. 47, P < 0. 001). EMS score at the last follow-up was significantly higher than that before surgery (14. 45±0. 93), 17. 09±1. 45, P< 0. 001). (3) Surgical satisfaction was excellent (n=16) or good (n=2). (4) At the last follow-up, 18 patients had no adverse reactions related to implants, and the wound healed well without screw loosening. (5) The results showed that reasonable osteotomy correction with computer-assisted surgery and PSO osteotomy could effectively treat kyphosis of upper thoracic segment.

Percutaneous pedicle screw fixation combined with vertebroplasty for the treatment of Genant Ⅲ degree osteoporotic vertebral compression fractures / 中国骨伤

OBJECTIVE@#To investigate the clinical effect of percutaneous pedicle screw fixation(PPSF) combined with percutaneous vertebroplasty (PVP) in the treatment of Genant Ⅲ degree osteoporotic vertebral compression fractures (OVCFs).@*METHODS@#The hospitalized 83 patients with Genant Ⅲ degree OVCFs treated by PPSF combined with PVP from June 2015 to June 2017 were retrospectively analyzed, and 83 patients treated by PVP alone from January 2013 to June 2016 were randomly selected as the control group. There were 19 males and 64 females with an average age of (73.6±11.0) years in combined group with treatment of PPSF and PVP. There were 15 malesand 68 females with an average age of (75.5±10.6) years in control group. The anterior edge height of the vertebral body and Cobb angle before operation, 1 day, and 6, 12, 24 months after operation were compared between two groups. Visual analogue scale(VAS) and Oswestry Disability Index (ODI) were used to assess the pain level and daily lumbar dysfunction for patients, respectively. The complications were observed.@*RESULTS@#The follow-up time of all patients was more than 2 years. The combined group and control group were (24.3±10.2) months and (27.5±14.8) months, respectively. There were no statistically significant differences in the anterior edge height of the vertebral body and Cobb angle at 1 day after surgery between two groups (>0.05), and there were statistically significant differences at 6, 12, 24 months after surgery between two groups (<0.01). The difference in ODI and VAS scores at 6 and 12 months after operation between two groups was statistically significant (<0.05). Postoperative complications incontrol group were higher than those in the combined group.@*CONCLUSION@#PPSF combined with PVP for the treatment of Genant Ⅲ degree OVCFs is superior to PVP alone in terms of vertebral height loss, patient satisfaction, and complications.

Ct morphometry of typical cervical vertebral pedicles for clinical accuracy in cervical pedicle screw insertion

Background: Pedicle screw fixation for mid- and lower cervical spine reconstruction has a potential risk of injuryto surrounding structures. To achieve optimal surgical outcomes, it is therefore necessary that pertinentanatomical data, especially with regard to pedicles and vertebral bodies be considered prior to surgery.Methods: 63 patients were scanned using axial CT parallel to the upper endplate of the vertebral body (C3–C6)with a helical CT scanner. Foramen width (FW), Foramen height (FH), Pedicle width (PW), Foramen angle (FA),Pedicle transverse angle (PTA), Lateral mass angle (LMA) were measured. Mean value and standard deviation ofeach parameter were calculated.Results: Mean FW ranged from 5.8 to 6.1 mm with non-significant difference from C3 to C6.The mean FH rangedfrom 4.9 to 5.1 mm, with non-significant differences between each vertebra. The mean PW ranged from 5.3 to 5.8mm. There were significant differences between each vertebra, except for the PW between C3 and C4. The FAranged from 17.5 to 18.5. There were significant differences between each vertebra, except for the FA between C3and C6. The mean PTA ranged from 39.8 to 35.8. The mean LMA ranged from 0.9 to 3.1.There were significantdifferences between each vertebra, except for the LMA between C4 and C5. The FW and FH exhibited no correlationswith PW, PTA or LMA. FA was found to be positively correlated with both PTA and LMA. There was also a positivecorrelation between PTA and LMA.Conclusion: Anatomical features of the cervical spine using CT to select safer screw insertion techniques arehighly recommended. In cases in which insertion of pedicle screws is difficult, Lateral Mass Screw (LMS) can beinserted safely. Whereas when insertion of LMS is difficult, insertion of pedicle screws can be performed easily.

Surgical Treatment of Osteoporotic Vertebral Compression Fractures at Thoraco-Lumbar Levels: Only Pedicle Screw Constructs with Polymethylmethacrylate Augmentation / 대한정형외과학회잡지

PURPOSE: To investigate the radiological efficacy of polymethylmethacrylate (PMMA) augmentation of pedicle screw operation in osteoporotic vertebral compression fractures (OVCF) patients. MATERIALS AND METHODS: Twenty OVCF patients, who underwent only posterior fusion using pedicle screws with PMMA augmentation, were included in the study. The mean follow-up period was 15.6 months. The demographic data, bone mineral density (BMD), fusion segments, number of pedicle screws, and amount of PMMA were reviewed as medical records. To analyze the radiological outcomes, the radiologic parameters were measured as the time serial follow-up (preoperation, immediately postoperation, postoperation 6 weeks, 3, 6 months, and 1 year follow-up). RESULTS: A total of 20 patients were examined (16 females [80.0%]; mean age, 69.1±8.9 years). The average BMD was −2.5±0.9 g/cm2. The average cement volume per vertebral body was 6.3 ml. The mean preoperative Cobb angle of focal kyphosis was 32.7°±7.0° and was improved significantly to 8.7°±6.9° postoperatively (p<0.001), with maintenance of the correction at the serial follow-up, postoperatively. The Cobb angle of instrumented kyphosis, wedge angle, and sagittal index showed similar patterns. In addition, the anterior part of fractured vertebral body height averaged 11.0±5.0 mm and was improved to 18.5±5.7 mm postoperatively (p=0.006), with maintenance of the improvement at the 3-month, 6-month, and 1-year follow-up. CONCLUSION: The reinforcement of pedicle screws using PMMA augmentation may be a feasible surgical technique for OVCF. Moreover, it appears to be appropriate for improving the focal thoracolumbar/lumbar kyphosis and is maintained well after surgery.

Unilateral pedicle screw fixation and lumbar interbody fusion under the Quadrant tunnel for the treatment of prolapsed lumbar disc herniation in young patients / 中国骨伤

OBJECTIVE@#To explore the clinical effect of unilateral screw fixation and lumbar interbody fusion under the Quadrant tunnel to treat prolapsed lumbar disc herniation in young patients.@*METHODS@#Between January 2015 and January 2017, 18 young patients with prolapsed lumbar disc herniation were treated with unilateral pedicle screw fixation and lumbar interbody fusion under Quadrant tunnel. Among them, there were 10 males and 8 females, aged from 20 to 28 years old with an average of 22.5 years. The VAS, lumbar JOA scores were compared before sutgery, 1 and 3 months after surgery and at the final follow-up. The improvement of clinical symptoms and bone fusion rate were evaluated according to the improved rate of JOA score and X-rays data at the final follow-up.@*RESULTS@#All 18 patients were followed up from 14 to 34 months with an average of 24.3 months. All incisions got primary healing, and no nerve root injury, screw loose or rupture, threaded fusion cage sink or other complications were found. The postoperative VAS, lumbar JOA scores were improved significantly(<0.05). Neurologic function improved significantly in the final follow-up. The postoperative JOA improvement rate was excellent in 10 cases, good in 6 cases, and fair in 2 cases. Postoperative bone graft fusion rate was 100% at 3 to 6 months.@*CONCLUSIONS@#Unilateral screw fixation and lumbar interbody fusion under the Quadrant tunnel is an effective and safe method in treating prolapsed lumbar disc herniation for young patients, it has advantage of short operation time, small trauma and short hospitalization time. However, the indications should be well considered.

Clinical evaluation of a bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate: 128 osteoporotic patients with 42 months of follow-up

OBJECTIVES: To evaluate the safety and efficacy of a novel bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate in osteoporotic spinal surgery. METHODS: This study included 128 patients with osteoporosis (BMD T-score −3.2±1.9; range, −5.4 to -2.5) who underwent spinal decompression and instrumentation with a polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw. Postoperative Visual Analogue Scale scores and the Oswestry Disability Index were compared with preoperative values. Postoperative plain radiographs and computed tomography (CT) scans were performed immediately after surgery; at 1, 3, 6, and 12 months; and annually thereafter. RESULTS: The mean follow-up time was 42.4±13.4 months (range, 23 to 71 months). A total of 418 polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screws were used. Cement extravasations were detected in 27 bone cement-injectable cannulated pedicle screws (6.46%), mainly in cases of vertebral fracture, without any clinical sequela. The postoperative low back and lower limb Visual Analogue Scale scores were significantly reduced compared with the preoperative scores (<0.01), and similar results were noted for the Oswestry Disability Index score (p<0.01). No significant screw migration was noted at the final follow-up relative to immediately after surgery (p<0.01). All cases achieved successful bone fusion, and no case required revision. No infection or blood clots occurred after surgery. CONCLUSIONS: The polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw is safe and effective for use in osteoporotic patients who require spinal instrumentation.

Morphometric Study Of Pedicles Of Dried Adult Human Lumbar Vertebrae In Udaipur Zone

Introduction: It has been suggested that reduced inter-pedicular distance is one of the cause of primary narrowingof the spinal canal may lead to low back pain.Transpedicular approaches are being widely used in many surgeriessuch as bone biopsy, bone grafting, Pedicle screw fixation, vertebroplasty and kyphoplasty. The morphometricdata of lumbar vertebra from Udaipur district i.e. in southern Rajasthan is to the best of our knowledge, virtuallyunexplored so we under took this study.Aims and objectives: The present study aims at determining the morphometric norms of Pedicle of the lumbarvertebra in Udaipur zone measured in dried bone. In this study the following measurements on Pedicle of lumbarvertebra are taken i.e. pedicle height, pedicle width and Interpedicular distance.Materials and methods: The present study was done on the 110 dry adult human lumbar vertebrae from variousmedical colleges of Udaipur. The morphometrical data of the Pedicle of human lumbar vertebrae were measuredand analysed. Digital vernier calliper was used to measure the morphometric data.Result and discussion: The pedicle height of Pedicle decreased from L1 to L5 except in L2 and width of Pedicleincreased from L1 to L5. Interpedicular distanced gradually increased from L1 to L5.

Treatment of senile spinal tuberculosis with posterior percutaneous pedicle screw fixation combined with local percutaneous endoscopic debridement / 中国骨伤

OBJECTIVE@#To explore the short-term efficacy of posterior percutaneous screw fixation combined with local percutaneous endoscopic debridement in treating senile spinal tuberculosis.@*METHODS@#The clinical data of 19 senile patients with spinal tuberculosis underwent surgical treatment from January 2015 to September 2016 were retrospectively analyzed. There were 13 males and 6 females, aged from 60 to 73 years old with an average of (66.2±4.0) years. All patients have been diagnosed with spinal tuberculosis prior to hospitalization with abscess, dead bone formation but no sinus, neurological symptoms, open surgical indications. All patients were treated with posterior percutaneous screw fixation combined with local percutaneous endoscopic debridement, and were given appropriate chemotherapy for 3 weeks preoperatively. Pre-and post-operative visual analogue score (VAS), Oswestry Disability Index (ODI), sagittal Cobb angle of lesion segment, erythrocyte sedimentation rate(ESR), C-reactive protein(CRP) were analyzed.@*RESULTS@#All the 19 patients successfully completed the operation and passed through the perioperative period safely. The operation method was unchanged during the operation. The average operation time was (153.2±14.0) min. Except for 1 patients who had delayed incision healing, other patients healed at I stage within 2 weeks after operation. All patients were followed up for 15 to 26 months with an average of (19.6±3.2) months.VAS, ODI, sagittal Cobb angle of lesion segment, ESR, CRP were decreased from preoperative(5.9±1.1) points, (80.9±4.0)%, (30.8±5.5)°, (79.6±14.4) mm/h, (56.9±9.5) mg/L to(1.8±0.9) points, (66.4±5.4)%, (15.9±2.5)°, (20.4±4.6) mg/L, (32.0±8.1) mm/h at final follow-up(<0.05).@*CONCLUSIONS@#Senile spinal tuberculosis have more complications and poor general body condition. Posterior percutaneous pedicle screw fixation combined with local percutaneous endoscopic debridement in treating the patients can reduce trauma, got satisfactory effect.

Percutaneous pedicle screw fixation combined with limited-open decompression technique for thoracolumbar fractures with neurologic deficit / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effects of percutaneous pedicle screw fixation combined with limited open decompression technique for the treatment of thoracolumbar fractures with neurologic deficit.</p><p><b>METHODS</b>The clinical data of 76 patients with thoracolumbar fractures with neurologic deficit underwent percutaneous pedicle screw fixation combined with limited open decompression technique from June 2010 to June 2014 were retrospectively analyzed. There were 45 males and 31 femals, aged from 17 to 56 years with an average of 32.5 years old. According to the classification of Denis, 33 cases were type A, 26 cases were type B, 17 cases were type C. According to the criterion of American Spinal Injury Association(ASIA), 13 cases were grade A, 9 cases were grade B, 21 cases were grade C, 33 cases were grade D. The operative time, intraoperative blood loss, postoperative internal fixation lossening and breakage were recorded. The informations of the Cobb angle, the anterior height of injured vertebra, canal stenosis were observed before operation, 3 days after operation, and the final follow-up. The improvement of neurologic function were analyzed at final follow-up.</p><p><b>RESULTS</b>All the patients were followed up from 13 to 47 months with an average of 32.1 months. The mean operative time was 159 min (136 to 218 min) and the intraoperative blood loss was 225 ml(150 to 360 ml). The anterior height of injured vertebra was increased from (52.0±5.9)% before operation to (87.2±1.8)% at 3 days after operation, and (86.1±1.5)% at final follow-up (=45.27,=0.000); the Cobb angle was decreased from (29.7±8.2)° before operation to (5.7±2.9)° at 3 days after operation, and (5.9±3.6)° at final follow-up (=34.62,=0.000); the canal stenosis was decreased from (37.5±7.2)% before operation to (12.3±3.3)% at 3 days after operation, and (11.9±3.1)% at final follow-up(=37.02,=0.000); there was no significant differences between postoperative 3 days and the final follow-up about the above parametres(>0.05). According to ASIA criterion, the spinal cord function was classified as grade A in 13 cases, grade B in 0 cases, grade C in 10 cases, grade D in 21 cases and grade E in 32 cases at final follow-up. Internal fixation lossening and breakage occurred in 2 cases.</p><p><b>CONCLUSIONS</b>Percutaneous pedicle screw fixation combined with limited open decompression technique can obtain satisfactory clinical effect for patients with thoracolumbar fractures with neurologic deficit, and have a good recovery of nerve function can be observed.</p>

Progress on clinical application of anterior cervical pedicle screw fixation for instable cervical spine disease / 中国骨伤

Instability of the cervical spine disease requires surgery to restore stability. In the past, surgical methods were divided into two kinds of anterior and posterior. But each has its own disadvantages:anterior vertebral screw has a higher failure rate, sometimes need a second operation; and posterior pedicle screw, lateral mass screw and facet joint screw may make greater trauma, lead to longer hospitalization. For general instable cervical spine disease, according to the location of the disease, only with the anterior or posterior approach can achieve a stable effect. However, it often fails to achieve the desired stability with only anterior or posterior approach for the three column injury of single segment, the disease need for multi-segment corpectomy and discectomy. Meanwhile, combined with the anterior and posterior have more obvious disadvantages:such as prolonged operation time, greater surgical injury, increased risk of infection and so on.In recent years, anterior transpedicular screw (ATPS) as a new technique was used for cervical spine fixation. Its laboratory and clinical studies have been conducted about biomechanical properties, morphological feasibility, pull-out strength, radiological features and new technology for inserting screws. Because of its strong stability, perfect mechanical properties and the satisfactory results of patients, which has been recognized by many scholars. Although this technique has been used in clinical practice, Its long-term clinical effect needs to be further clarified. Even so, the innovative proposal will provide a new thread for the majority of doctors and colleagues in treating unstable cervical disease.

Radiographic and Clinical Outcomes of Robot-Assisted Posterior Pedicle Screw Fixation: Two-Year Results from a Randomized Controlled Trial

PURPOSE: We prospectively assessed the early radiographic and clinical outcomes (minimum follow-up of 2 years) of robot-assisted pedicle screw fixation (Robot-PSF) and conventional freehand pedicle screw fixation (Conv-PSF). MATERIALS AND METHODS: Patients were randomly assigned to Robot-PSF (37 patients) or Conv-PSF (41 patients) for posterior interbody fusion surgery. The Robot-PSF group underwent minimally invasive pedicle screw fixation using a pre-planned robot-guided screw trajectory. The Conv-PSF underwent screw fixation using the freehand technique. Radiographic adjacent segment degeneration (ASD) was measured on plain radiographs, and clinical outcomes were measured using visual analogue scale (VAS) and Oswestry disability index (ODI) scores regularly after surgery. RESULTS: The two groups had similar values for radiographic ASD, including University California at Los Angeles grade, vertebral translation, angular motion, and loss of disc height (p=0.320). At final follow-up, both groups had experienced significant improvements in back VAS, leg VAS, and ODI scores after surgery (p < 0.001), although inter-group differences were not significant for back VAS (p=0.876), leg VAS (p=0.429), and ODI scores (p=0.952). In the Conv-PSF group, revision surgery was required for two of the 25 patients (8%), compared to no patients in the Robot-PSF group. CONCLUSION: There were no significant differences in radiographic ASD and clinical outcomes between Robot-PSF and Conv-PSF. Thus, the advantages of robot-assisted surgery (accurate pedicle screw insertion and minimal facet joint violation) do not appear to be clinically significant.

Treatment of thoracolumbar burst fractures with intelligent inflated reduction combined with percutaneous pedicle screw fixation / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical outcome of intelligent inflated reduction combined with percutaneous pedicle screw fixation in treating thoracolumbar burst fractures.</p><p><b>METHODS</b>The clinical data of 22 patients with thoracolumbar burst fractures of single segment treated from January 2013 to December 2015 were retrospectively analyzed. There were 12 males and 10 females, aged from 32 to 56 years old with an average of (42.4±8.6) years. Self-made intelligent pneumatic reset instrument was applied to 22 cases under anaesthesia reduction, and then percutaneous pedicle screw fixation was performed. Clinical features were observed and the clinical effects were evaluated by VAS, ODI, kyphotic angle (Cobb angle) and the injured vertebral anterior border height before and after operation.</p><p><b>RESULTS</b>All the patients were followed up from 1 to 2.5 years with an average of 18 months. All fractures obtained bone healing, no complications such as loosening, displacement, breakage of pedicle screw and kyphosis were found. Preoperative, 1 week postoperative, and final follow-up, VAS scores of lumbar pain were 7.82±0.85, 3.09±0.92, 1.05±0.72;ODI scores were 84.2±11.2, 46.3±9.0, 12.2±4.3;Cobb angle were (16.3±5.4)°, (3.7±2.2)°, ( 5.5±2.6)°; the injured vertebral anterior border heights were (59.5±7.8)%, (86.9±6.0)%, (83.5±5.5)%, respectively. There was significant differences in VAS, ODI scores between any two times(<0.05). At 1 week postoperative and final follow-up, Cobb angle, injuried vertebral anterior border height were obviously improved (<0.05), and there was no significant difference between postoperative 1 week and final follow-up (>0.05).</p><p><b>CONCLUSIONS</b>It is safe and feasible surgical technique that intelligent inflated reduction combined with percutaneous pedicle screw fixation for thoracolumbar burst fractures. It has advantage of little trauma, reliable fixation, and less complication, etc. Therefore, it is a better choice for single-segment thoracolumbar burst fractures.</p>

Effect observation of percutaneous pedicle screw fixation combined with percutaneous vertebroplasty for the treatment of osteoporotic thoracolumbar fractures / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effects of percutaneous pedicle screw fixation(PPSF) combined with percutaneous vertebroplasty(PVP) for the treatment of osteoporotic thoracolumbar fractures.</p><p><b>METHODS</b>The clinical data of 94 patients with osteoporotic thoracolumbar fractures treated from January 2014 to December 2015 were retrospectively analyzed. There were 31 males and 63 females, aged from 65 to 70 years old with an average of 67.2 years. Fracture level was T₁₁ on 15 cases, T₁₂ on 32 cases, L₁ on 29 cases and L₂ on 18 cases. The patients were divided into two groups according to different therapeutic methods. Percutaneous pedicle screw fixation combined with percutaneous vertebroplasty were applied in 43 patients(group A) and percutaneous vertebroplasty was applied to 51 patients(group B). Operation time, intraoperative blood loss, bone cement volume, postoperative in-bed time were recorded; preoperatively, 3 d, 1 year after the operation, the ratios of anterior border heights, sagittal Cobb angles, visual analogue scale(VAS) scores were compared between two groups. The condition of postoperative complication in two groups was analyzed.</p><p><b>RESULTS</b>All the patients were followed up for 12 to 24 months with an average of 18.5 months. Operation time of group A [(96.2±28.7) min] was longer than that of group B [(31.8±10.6) min]. Intraoperative blood loss of group A[(62.2±25.5) ml] was more than that of group B [(25.4±10.9) ml]. Bone cement volume of group A [(5.5±0.5) ml] was larger than that of group B [(4.9±1.1) ml]. Postoperative in-bed time of group A[(5.1±1.8) d] was longer than that of group B[(1.8±0.7) d]. There were significant differences in operation time, intraoperative blood loss, bone cement volume, postoperative in-bed time between two groups(<0.05). Three days, 12 months after the operation, the ratios of anterior border heights and Cobb angles in two groups were significantly improved. At final follow-up, the ratio of anterior border height and Cobb angle of group A[(85.6±3.5)%, (11.9±5.3)°] were better than of group B[(84.2±4.5)%, (15.3±3.4)°](<0.05). Three cases in group B had re-collapse of cemented vertebral bodies. Postoperative at 3 d, 1 year, VAS score of all patients had significantly decreased(<0.05), and there was no significant difference between two groups(>0.05).</p><p><b>CONCLUSIONS</b>Compared to simple PVP, PPSF combined with PVP in treating osteoporotic thoracolumbar fracture can obtain stronger vertebral strength and stiffness, furthermore to improve vertebral reduced effect, keeping vertebral heights, and preventing vertebral re-collapse.</p>