Posterior Pedicle Screw Fixation Research Articles

后路椎弓根钉固定联合椎管扩大成形治疗下颈椎骨折脱位的疗效观察

后路椎弓根钉固定联合椎管扩大成形治疗下颈椎骨折脱位的疗效观察

Analysis on the causes and prevention strategies of the vascular injury caused by the oblique lateral lumbar fusion

To analyze the causes of vascular injury occurred in oblique lateral interbody fusion for treating lumbar degenerative diseases, and put forward preventive measures. There were 235 patients analyzed from October 2014 to May 2017 in five hospitals, who were treated with oblique lateral interbody fusion with or without posterior pedicle screw fixation. There were 79 males and 156 females with an average age of (61.9±13.5) years old (ranged from 32 to 83 years). There were 7 cases of vascular injury, including 4 cases of segmental vessel injury, 1 case of left common iliac artery injury, 1 case of left common iliac veininjury and 1 case of ovarian vein injury. The follow up time ranged from 6 to 36 months, averagely (15.6±7.5) months. There was no pedicle screw loosen or fracture. The low back pain VAS decreased from preoperative 6.7±2.3 to 1.4±0.8 at the latest follow-up, which was statistically difference(t=7.21, P=0.033). The ODI decreased from preoperative (36.5±7.7)% to (9.4±3.6)% at the latest follow-up, which was statistically difference (t=8.11, P=0.025). Oblique lateral interbody fusion technique provides a new method for minimally invasive fusion of lumbar internal fixation. However, it has a risk of vascular injury. In order to effectively prevent the occurrence of vascular injury, the operative indications and careful and meticulous operation should be strictly grasped.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation

OBJECTIVE To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures. METHODS Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis. RESULTS The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05). CONCLUSION The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Retrospective radiographic analysis of anterior lumbar fusion for high grade lumbar spondylolisthesis.

High-grade spondylolisthesis (>50% slippage) is infrequently encountered in adults and frequently requires surgical treatment. The optimal surgical treatment is controversial with limited literature guidance as to optimal approach to treatment. An observational study to examine the technique and radiographic outcomes of adult patients treated with anterior lumbar interbody fusion (ALIF) and posterior percutaneous instrumentation for high-grade spondylolisthesis. ALIF was performed in 5 consecutive patients (3/5 female, 2/5 male) aged 29-67 years old who presented with low back pain and L5 radiculopathy. All patients failed conservative treatment and were treated with L4-5 and L5-S1 ALIF followed by posterior percutaneous L4-S1 pedicle screw and rod fixation. Pre- and postoperative clinical data was collected including L5-S1 posterior disk height in millimeters, millimeters of spondylolisthesis at L5-S1, degrees of segmental lordosis (L4-S1), lumbar lordosis (L1-S1), and lumbar lordosis pelvic incidence (LL-PI) mismatch. Six weeks following surgery, no patient reported residual L5 radicular symptoms. At last follow up, patient satisfaction, according to Modified Macnab Criteria, was excellent in 4/5 patients and good in 1/5 patient. In the 4 patients with greater than 1 year radiographic follow up, fusion rate was 100% on computed tomography (CT). Mean increase in posterior disk height was 12.5 mm (range, 11.4-13.5 mm). Mean reduction in spondylolisthesis was 58.7% (range, 20.2-100%). Mean segmental (L4-S1) and overall (L1-S1) lumbar lordosis increased by 23.6% (range, 6.5-41.7%) and 16.6% (2.5-31.5%), respectively. Following surgery, LL-PI mismatch decreased from a mean of 16.4 to 10.2 degrees. ALIF with posterior percutaneous instrumentation is a safe and effective treatment for high-grade lumbosacral spondylolisthesis in properly selected adults. This technique improves lumbar sagittal parameters and reduces spondylolisthesis. The indirect neural decompression from simultaneous disk height restoration and spondylolisthesis reduction may be associated with lower neurological injury rate compared to posterior-only. Future prospective study is needed to validate this hypothesis.

Esophageal perforation following pedicle screw placement for the treatment of upper thoracic spinal tuberculosis: a case report and review of the literature

BackgroundThe technique of posterior pedicle screw fixation has already been widely applied in the treatment of upper thoracic spinal tuberculosis. However, lesions of tuberculosis directly invade the vertebrae and surrounding soft tissues, which increases the risk of esophageal perforation induced by the posterior pedicle screw placement. Herein, we report the first case of esophageal perforation following pedicle screw placement in the upper thoracic spinal tuberculosis, and describe the underlying causes, as well as the treatment and prognosis.Case presentationA 48-year-old female patient with upper thoracic spinal tuberculosis presented sputum-like secretions from the wound after she was treated with one-stage operation through the posterolateral approach. Endoscopy was immediately conducted, which confirmed that the patient complicated with postoperative esophageal perforation caused by screws. CT scan showed that the right screw perforated the anterior cortex of the vertebrae and the esophagus at the T4 level. Fortunately, mediastinal infection was not observed. The T4 screw was removed, Vacuum Sealing Drainage (VSD) was performed, and jejunum catheterization was used for enteral nutrition. After continuous treatment with sensitive antibiotics for 2.5 months and 5 times of VSD aspiration, the infected wound recovered gradually. With 18-month follow-up, the esophagus healed well, without symptoms of dysphagia and stomach discomfort, and CT scan showed that T2–4 had complete osseous fusion without sequestrum.ConclusionTuberculosis increases the risk of postoperative esophageal perforation in a certain degree for patients with upper thoracic tuberculosis. The damages to esophagus during the operation should be prevented. The screws with the length no more than 30 mm should be selected. Moreover, close monitoring after operation should be conducted to help the early identification, diagnosis and treatment, which could help preventing the adverse effects induced by the delayed diagnosis and treatment of esophageal perforation.

Massive subcutaneous hematoma of the anterior abdominal wall at the heparin injection site following anterior lumbar interbody fusion: a case report and review of literature

Introduction: Various vascular complications of anterior lumbar interbody fusion (ALIF) have been reported in the orthopedic literature. However, a subcutaneous hematoma is an unexpected complication, especially following minimally invasive ALIF. Patient Concerns: We report a very rare case of a heparin-induced subcutaneous hematoma in a 25-year-old man who underwent a revision L5/S1 ALIF followed by a computer-assisted posterior pedicle screw fixation. Diagnosis: Massive subcutaneous hematoma of the anterior abdominal wall was diagnosed. Interventions: The patient presented with a massive, tense and severely painful lump at the subcutaneous heparin injection site affecting the left anterior abdominal wall on the fifth postoperative day. An urgent computer tomography angiography scan revealed a massive abdominal wall hematoma arising from one of the left deep inferior epigastric artery perforators. The patient was taken back to the operating theater for an evacuation of the hematoma and subsequently recovered without any further complications. Outcomes: The patient was discharged without complication on the postoperative sixth day. Conclusion: This is the first documented case of a massive subcutaneous hematoma of the abdominal wall following a minimally invasive ALIF procedure. This report adds to the body of evidence on the risk of postoperative bleeding in patients following ALIF surgery. Also, spine surgeons need to be aware that subcutaneous injury to the abdominal wall deep inferior epigastric artery perforators at the site of the heparin injection can rarely occur. Therefore heparin injection sites remote from the anterior abdominal wall must be considered especially following ALIF surgery.

Short-term posterior C1-C2 pedicle screw fixation without fusion to treat type II odontoid fracture among people under 60years.

Posterior C1-C2 pedicle screw fixation is a reliable technique used in treatment of type II odontoid fracture. However, the loss of cervical range of rotation motion (RORM) was inevitable. There were few studies focusing on the influence of short-term C1-C2 fixation with nonfusion technique to preserve cervical function in patients younger than 60years. The purpose of this study was to compare cervical RORM which was measured by an improved goniometer, and the clinical outcomes between short-term and long-term C1-C2 fixation techniques in the treatment of Grauer type 2B and 2C odontoid fracture. This study represents a retrospective analysis, including patients who underwent primary C1-C2 fixation surgery. These patients were divided into short-term and long-term groups based on whether underwent a fixation removal operation. The clinical results were collected and compared between the two groups. Independent T test and Chi-square analyses were used to identify significant differences between the two groups and dependent T test was used within each group. Statistical significance was set at p < .05. There were no severe postoperative complications, and all 60 patients achieved spinal stabilization after primary surgery. The mean rotation angle in the short-term group at last follow-up time was 138.39 ± 21.06°, which was better than 83.59 ± 13.06° in the long-term group (p < .05). The same statistical difference was observed in flexion-extension angle, which was 71.11 ± 18.73° in short-term group and 53.34 ± 18.23° in long-term group. The mean NDI score in short-term group at last follow-up time was 1.23 ± 0.86 and better than 8.24 ± 3.17 in long-term group. However, the VAS score in short-term group was 1.82 ± 0.54 which was worse compared to 0.64 ± 0.29 in long-term group. The results demonstrated that primary C1-C2 fixation with nonfusion technique could support satisfactory clinical effects. In addition, the removal of instruments after bony fusion could improve the function of cervical movement significantly in patients under 60years.

Percutaneous transpedicular lumber fixation

Background: Posterior Pedicle screw fixation has step by step become popular to thoracolumbar fracture management. Since Roy-Camille et al used application of plates with pedicle screws for thoracolumbar fractures in 1963. Aim of the work: to evaluate the percutaneous transpedicular fixation for management of lumbar fractures. Patients and Methods: This research was done on 20 patients presented by lumbar spine fractures; they were treated with percutaneous transpedicular fixation and stabilization at Al-Azhar University hospitals from June 2019 to February 2020. All patients were without neurological deficits they were fixed either one level above and one level below or two levels above and two levels below the fractured vertebra. Results: Clinical and functional outcomes are preferable or comparable to conventional open procedures. The key disadvantages of this procedure are the steep learning curve and radiation exposure to both doctors, nurses and surly patients, which may be reduced as much as possible by using the new 3D CT screw insertion process. Conclusion: Percutaneous transpedicular spine fixation is a secure technique that follows the same principles as open procedures, allowing the surgeon to conduct biomechanically strong internal spinal fixation with minimal tissue damage, and is a suitable choice for the treatment of unstable thoracolimber fractures with no neurological deficit. This has the benefit of short-time surgery, no loss of blood, almost no muscle damage results in less postoperative pain than conventional open procedures, short hospitalization, early mobilization, a quicker return to work and a low risk of complications

Clinical outcomes of posterior laminectomy and pedicle screw fixation for upper cervical intraspinal tumors: a case series.

ObjectiveThis study was performed to introduce posterior laminectomy and pedicle screw fixation for the treatment of upper cervical spinal cord tumors and investigate the curative effects.MethodsEighteen patients (11 men, 7 women) who underwent surgical treatment of an upper cervical intraspinal tumor from January 2008 to June 2013 were reviewed. Clinical parameters including age, sex, affected spinal levels, lesion location, duration and type of symptoms, and pathological features were retrospectively investigated.ResultsThe mean operation time was 181.9 ± 25.5 minutes (range, 135–240 minutes), and the mean blood loss volume was 1038.9 ± 284.2 mL (range, 750–1530 mL). The Frankel grade, Japanese Orthopaedic Association score, and Karnofsky performance status score were significantly better postoperatively than preoperatively. The radiographic examination revealed good bone graft fusion. Two patients developed tumor recurrence, while four patients developed intraoperative or postoperative complications.ConclusionsManagement of upper cervical intraspinal tumors by posterior laminectomy and pedicle screw fixation can relieve compression of the cervical cord and nerve root, thoroughly remove the tumor lesion, reconstruct the stability of the upper cervical spine, and improve patients’ quality of life.

Outcome of Surgical Treatment of Spontaneous Spinal Epidural Abscesses for a 10-year Period.

Spinal epidural abscess is uncommon but potentially debilitating infection. Delay in early diagnosis may be associated with increased morbidity and mortality despite recent advances in medicine. To present the clinical course and outcome of treatment of spontaneous spinal epidural abscesses. Thirty-four patients (20 men and 14 women) with clinical, neuroimaging and/or histological data for spinal epidural abscess were treated at the Clinic of Neurosurgery at St George University Hospital, Plovdiv, Bulgaria, for the period 2009-2018. The average age of patients was 62 years (21-76 years) and the ratio of men to women was 1.4:1. All patients (100%) presented with vertebralgia, 13 patients (38.2%) had additional radiculalgia, and 10 patients (29.4%) presented with sensory or motor deficit. The duration of complaints varied from 4 to 180 days. At hospital admission, only 9 patients (26.4%) had intact neurological status. The most common localization of the spinal epidural abscess was in the lumbar and lumbosacral area (52.9%), concomitant spondylodiscitis was present in 31 patients (91.2%). Twenty-four patients (70.6%) underwent emergency surgery within 24 hours, and the rest had planned surgery. Decompressive interlaminotomy or hemilaminectomy was performed in 9 patients (26.5%). The remaining 25 patients (73.5%) underwent laminectomy, in 15 patients (44.1%) it was combined with posterior pedicle screw fixation. After the treatment, 23 patients (67.6%) had a good outcome, the remaining 11 (32.4%) had a poor outcome, and 3 patients died (8.8%). In patients with spinal epidural abscess, emergency surgery is the treatment method of choice. It allows decompression of neural structures, correction of the spinal deformity, segmental stabilization and rapid mobilization of patients.

Minimally invasive spinal fusion technique in patients with lumbar segmental instability.

Background: Lumbar fusion is a common surgical procedure for treatment of back pain caused by degeneration of lumbar disc. The aim of fusion is to prevent motion in the destabilized segments to decrease the back pain . All types of interbody fusion approaches work with posterior pedicle screw fixation to increase stabilization and fusion rates. It has some disadvantages including paraspinal muscle dissection, screw malposition, neurologic risk , increased the time of operation with blood loss and risk of infection. A modified interspinous device can provide stabilization similar to pedicular screw fixation avoiding its complication when used for interbody fusion as a minimally invasive procedur. Patient and Methods: The study involved 20 patients with moderate segmental instability in lumbar spine . Transforaminal interbody fusion using the polyethere- therketone( PEEK )cage and rigid interspinous device fixation was performed. Patients were followed up and treatment outcomes were assessed within approximately 24 months after surgery. Results: according to pain intensity level on the visual analogue scale, the need for painkillers and the quality of life according to the Oswestry Disability Index scale during the early postoperative period demonstrated significantly better outcomes due to a less severe operative trauma to the paravertebral soft tissues. The formation of interbody bone formation was observed after 20—36 months in 94% of patients . Postoperative complications occurred in 2.2% of patient. Conclusion: The use of transforaminal interbody fusion and rigid interspinous stabilization provides better clinical outcomes and fewer postoperative complications in patients with moderate lumbar segmental instability.

239. Comparison of single-position robot-assisted surgery vs conventional minimally invasive surgery following LLIF: an in vitro assessment

BACKGROUND CONTEXT Lateral lumbar interbody fusion (LLIF) provides indirect decompression of the neural elements while minimizing the potential vascular complications associated with anterior lumbar interbody fusion (ALIF). Posterior fixation may be applied through various techniques such as conventional minimally invasive surgery (CMIS), requiring the patient to be repositioned prone to provide access to both pedicles. Conversely, robot-assisted navigation (RAN) of pedicle screws can be utilized from a single position without flipping the patient. RAN is theorized to reduce patient surgical time, radiation, and blood loss due to positioning and workflow effects. PURPOSE To evaluate the effect of robot-assisted navigation in comparison to CMIS methods in terms of surgical time, radiation exposure, and pedicle screw accuracy. STUDY DESIGN/SETTING Cadaveric study. PATIENT SAMPLE N/A OUTCOME MEASURES N/A METHODS Twelve unembalmed human torsos were implanted with 2-level static LLIF cages, followed by posterior bilateral pedicle screw fixation using either CMIS (n=6) or RAN (n=6). Preoperative computed tomography (CT) RAN workflow utilized CT scans of the specimen taken offsite and transferred to the robotic system during setup. Screw planning was performed using these CT scans, and then was merged with intraoperative fluoroscopy. Surgical times, surgeon radiation exposure, and screw accuracy were measured. Patient flip time from a consecutive patient series was included. RESULTS Significant differences in surgical times and radiation dosages were found between groups. Surgical time for preoperative RAN and CMIS was 64.7 min±4.1 min and 123.0 min±13.7 min, respectively. Time per screw for RAN and CMIS workflows was 2.7±0.6 min and 4.3±1.3 min, respectively. RAN was significantly different for total operative time and time per screw in comparison to CMIS (p CONCLUSIONS Significant differences were found in both surgical time and radiation exposure between CMIS and RAN, with RAN resulting in shorter surgical times and less radiation exposure to the surgeon than CMIS. Consideration should be given to single-position LLIF procedures that utilize RAN to instrument the spine with bilateral pedicle screws. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

56. Minimally invasive pedicle screws provide similar clinical outcomes to open posterior fusion in the management of adult isthmic spondylolisthesis

BACKGROUND CONTEXT In adult patients undergoing anterior lumbar interbody fusion (ALIF) for the treatment of isthmic spondylolisthesis, the literature shows that posterior percutaneous pedicle screw fixation leads to shorter hospital stays, less time under anesthesia, and less intraoperative blood loss compared to open posterior fusion. However, there is conflicting evidence on whether patients undergoing posterior percutaneous fixation experience similar clinical outcomes as those undergoing open posterior fusion. PURPOSE The purpose of this study was to determine the impact of minimally invasive posterior surgery on clinical outcomes following lumbar spinal fusion for isthmic spondylolisthesis. STUDY DESIGN/SETTING This study was a retrospective analysis of prospectively collected data from a single, high-volume academic medical center. PATIENT SAMPLE Analysis of patients who underwent lumbar fusion for isthmic spondylolisthesis from 2014 to 2019 was conducted. Surgery was indicated after failure of conservative treatment to address lumbar radiculopathy and/or neurogenic claudication. OUTCOME MEASURES Patient-reported outcome measures (PROMs) were recorded at preoperative and postoperative clinical visits, and included the Visual Analog Scale back pain (VAS back) and leg pain (VAS leg), the Short-Form 12 Mental Component Score (MCS-12) and Physical Component Score (PCS-12), and the Oswestry Disability Index (ODI). Secondary measures included estimated blood loss (EBL) and length of stay (LOS). METHODS Patient and surgical characteristics including age, gender, body mass index (BMI), Charlson Comorbidity Index (CCI), number of levels decompressed and number of levels fused were recorded. Preoperative and final PROMs were obtained from an institutional query. For analysis, patients were divided into two groups based on surgical approach: ALIF with percutaneous pedicle screws (Percutaneous) and ALIF with open posterior fusion (Open). Multivariate linear regression was performed to correlate surgical approach and outcomes. RESULTS A total of 61 patients were included, with 20 patients in the Percutaneous group and 41 patients in the Open group. Patients undergoing open surgery had greater intraoperative EBL (p=0.013) and longer LOS (p=0.034). Otherwise, there were no significant differences in patient characteristics. Patients in both the Percutaneous and the Open groups had significant improvement in VAS back scores (p=0.001, p CONCLUSIONS Our results suggest that patients undergoing minimally invasive posterior fusion and patients undergoing open posterior fusion for adult isthmic spondylolisthesis have similar improvement of PROMs from preoperative to final assessment. Additionally, open surgery is significantly correlated with less improvement in VAS leg scores than minimally invasive approaches and was associated with significantly higher intraoperative blood loss and hospital length of stay. This study underscores the importance of considering surgical approach as a prognostic factor. Furthermore, the results provide additional information that can be used by physicians in preoperative discussions with patients regarding expectations of postoperative improvements in pain. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Experimental study of individualized 3D printing-guided template combined with thoracolumbar pedicle screw placement for the treatment of ankylosing spondylitis

To evaluate accuracy and safety of individualized 3D printing guided template for thoracolumbar pedicle screw placement in patients with ankylosing spondylitis. From January 2016 to September 2019, thoracolumbar spine three-dimensional CT data of 8 patients with ankylosing spondylitis were included, Mimics 17.0 and ideaMaker computer software were applied to design thoracolumbar pedicle screw guided template of patients with AS, physical model of all patients (T10-L2)were printed by 3D printer, 2 parts in each patient, and divided into guide-plate-assisted screw group (experimental group) and free-hand nail group (control group). Thoracolumbar pedicle screws of both groups were placed by the same spinal surgeon. The accuracy of pedicle screw placement between two groups were evaluated according to results of postoperative CT, the accuracy of the fixation of thoracolumbar pedicle screw was divided into 4 grades, grade 0 and 1 screws were acceptable nails, grade 2 and 3 screws were unacceptable nails. The diameter and length of pedicle screws, the distance between entry point and posterior median line designed by preoperative 3D printing were compared with actual use in operation. Twenty three blocks of thoracolumbar 3D printing screw of ankylosing spondylitis guided templates were designed and printed in guide-plate-assisted screw group, 46 screws were inserted and 44 screws were accepted. The time of implanting a screw into thoracolumbar pedicle was (4.20±1.15) min, the frequency of X-ray was (5.00±1.25) times and the average adjustment times of screw and Kirschner needle during screw placement was (1.76±1.32) times. In the control group, 46 nails were placed by traditional surgical method and 30 screws were accepted. The time of implanting a screw into thoracolumbar pedicle was (14.67±2.23) min, the frequency of X-ray fluoroscopy was (14.46±2.21) times and the average times of Kirschner needle adjustment was (4.76±3.39) times. The success rates between experimental group and control group were 95.65%(44 / 46) and 56.22%(30 / 46) respectively, and had statistical difference (χ2=13.538, P<0.05). There was no significant difference in diameter, length of pedicle screws and the distance of posterior median line between virtual designed by 3D printing before operation and actual situation in opertaion (P>0.05). The operation time of inserting a single screw, the times of X-ray fluoroscopy, and the average times of adjustment screw and Kirschner needle in experimental group were significant less than those in control group(P<0.01). The personalized guide template assisted the thoracolumbar fixation designed by 3D printing could significantly improve safety, accuracy and efficiency of surgery, especially suitable for thoracolumbar vertebral bodies requiring posterior pedicle screw fixation for fracture or dislocation with AS.

Comparison of posterior open screw fixation with percutaneous fixation among traumatic thoracolumbar fracture patients.

Objectives: To compare outcome and adverse events of open posterior pedicle screw fixation with percutaneous posterior pedicle screw fixation among patients suffering traumatic thoracolumbar fractures in our population. Study Design: Retrospectively Analyzed. Setting: Department of Neurosurgery, DHQ Teaching hospital, Gujranwala. Period: June 2015 to May 2019. Material &amp; Methods: The patients who underwent open pedicle screw fixation (group 1) and percutaneous fixation (group 2) for traumatic thoracolumbar fractures information’s collected included patient’s age, gender, operation time, intra-operative blood loss, duration of radiation exposure during surgery, hospital stay duration, non-union at 6months and post-operative screw malpositioning and infection. Statistical analysis was done using SPSS version 25. Independent sample T test and Chi-square test for independence were used for quantitative and qualitative variables respectively to determine their significant association with type of surgery. The p values were statistically significant if &lt; 0.05. Results: Out of 82 patients, 60.9 (n=50) underwent open pedicle screw surgery and 39.1% (n=32) underwent percutaneous fixation. Both cohorts had similar preoperative data including age (p=0.54) and gender (p=0.505). In comparison to open surgery group, the patients who underwent percutaneous fixation had significantly lesser operation time (46.63 + 6.25 minutes vs 89.88 + 9.05 minutes, p&lt;0.01), lesser intraoperative blood loss (78.75 + 23.93 ml vs 330.40 + 101.87ml, p&lt;0.01), greater intraoperative fluoroscopic exposure time (400.19 + 31.22 seconds vs 190.06 + 30.28 seconds, p&lt;0.01), and lesser hospital stay time (3.13 + 0.871 days vs 5.08 + 1.209days, p&lt;0.01). The incidence of post-surgery complications like screw malpositioning (p=0.621) and infection (p=0.733) was similar in both cohorts. The fracture union rates were also comparable in both cohorts (p=0.664). Conclusion: Minimally inavsive percutaneous posterior pedicle screw fixation had lesser operation time, blood loss, and hospital stay duration and greater fluoroscopic exposure than conventional open posterior pedicle screw fixation among patients with traumatic thoracolumbar fractures in our studied population. It also had a similar radilogic outcome and post-operative adverse events like screw malpositioning and local infection, showing the non-inferiority as compared to conventional open instrumentation. Prospective trials with large sample size are required to find superiority if any of one modality over other exists in our people.

Short Segment versus Long Segment Posterior Pedicle Screws Fixation for Treatment of Thoracolumbar Burst Fracture: A Comparative Prospective Study

Background: The surgical treatment of unstable burst fracture (TLICS &gt;4) of the thoracolumbar vertebrae remain controversial. This study is aimed to compare the short segment versus long-segment posterior fixation for thoracolumbar burst fracture.The objective of the study is to study comparison of outcome of the Short-Segment Posterior Fixation (SSPF) versus Long-Segment Posterior Fixation (LSPF) for treatment of thoracolumbar burst fracture in term of surgical, radiological, neurological and functional outcome. Subjects &amp; Methods: In this prospective study, we included 32 patients with Burst fracture AO type A3, A4 of Thoracolumbar spine (T10-L2), who underwent posterior pedicle screw fixation for Burst fracture Thoracolumbar spine. A total of 18 of the patients underwent Short-Segment Posterior Fixation (SSPF) (Group A); group A is further divided into three subgroups A1: short-segment only(n=10), A2: short-segment with index screw(n=4) and A3: short-segment with anterior column reconstruction(n=4) with cage, Whereas 14 patients had Long-Segment Posterior Fixation (LSPF) (Group B). Surgical (duration of surgery, blood loss, complication), Clinical (Oswestry questionnaire, spinal cord independent measuring scale), radiological (percentage of anterior body height compression, kyphosis correction loss, Mc Cormack classification) and Neurological (Frankel grading) outcomes were analyzed. Results: The operative time Group A (159.85 min 22.5) was significantly shorter than Group B (198.7 31.5). Blood loss was significantly less in Group A (478 ml 259.3) than Group B (865ml 275.7). Kyphosis Correction loss at 6th month follow up in Group A (subgroup A1: 10.7deg 6.2, subgroup A2: 7.1deg 7.4 and subgroup A3: Subgroup A3: 6.1deg 5.2) was higher than that of group B (6.2deg 6.3). Complication (surgical site infection) occurred in Two patients in group B. There was no significant difference in terms of improvement in functional and neurological outcomes among both groups. The functional outcomes as per the SCIM and ODI score at 6th month follow up in group A: 74.7 +-22.29, 31.5+-13.73 respectively, and group B: 73.8+-26.07, 26.7+-17.9, respectively. Conclusion: Short-Segment Posterior Fixation (SSPF) is a significantly decreased duration of surgery and blood loss compare with Long-Segment Posterior Fixation (LSPF). Loss of kyphosis correction in Short-Segment Posterior Fixation (SSPF) may be decreased with index screws or anterior column reconstruction.

Design a novel integrated screw for minimally invasive atlantoaxial anterior transarticular screw fixation: a finite element analysis

PurposeTo design a new type of screw for minimally invasive atlantoaxial anterior transarticular screw (AATS) fixation with a diameter that is significantly thicker than that of traditional screws, threaded structures at both ends, and a porous metal structure in the middle. The use of a porous metal structure can effectively promote bone fusion and compensate for the disadvantages of traditional AATSs in terms of insufficient fixation strength and difficulty of bone fusion. The biomechanical stability of this screw was verified through finite element analysis. This instrument may provide a new surgical option for the treatment of atlantoaxial disorders.MethodsAccording to the surgical procedure, the new type of AATS was placed in a three-dimensional atlantoaxial model to determine the setting of relevant parameters such as the diameter, length, and thread to porous metal ratio of the structure. According to the results of measurement, the feasibility and safety of the new AATS were verified, and a representative finite element model of the upper cervical vertebrae was chosen to establish, and the validity of the model was verified. Then, finite element-based biomechanical analysis was performed using three models, i.e., atlantoaxial posterior pedicle screw fixation, traditional atlantoaxial AATS fixation, and atlantoaxial AATS fixation with the new type of screw, and the biomechanical effectiveness of the novel AATS was verified.ResultsBy measuring the atlantoaxial parameters, the atlantoaxial CT data of the representative 30-year-old normal adult male were selected to create a personalized 3D printing AATS screw. In this case, the design parameters of the new screw were determined as follows: diameter, 6 mm; length of the head thread structure, 10 mm; length of the middle porous metal structure, 8 mm (a middle porous structure containing an annular cylinder ); length of the tail thread structure, 8 mm; and total length, 26 mm. Applying the same load conditions to the atlantoaxial complex along different directions in the established finite element models of the three types of atlantoaxial fusion modes, the immediate stability of the new AATS is similar with Atlantoaxial posterior pedicle screw fixation.They are both superior to traditional atlantoaxial anterior screw fixation.The maximum local stress on the screw head in the atlantoaxial anterior surgery was less than those of traditional atlantoaxial anterior surgery.ConclusionsBy measuring relevant atlantoaxial data, we found that screws with a larger diameter can be used in AATS surgery, and the new AATS can make full use of the atlantoaxial lateral mass space and increase the stability of fixation. The finite element analysis and verification revealed that the biomechanical stability of the new AATS was superior to the AATS used in traditional atlantoaxial AATS fixation. The porous metal structure of the new AATS may promote fusion between atlantoaxial joints and allow more effective bone fusion in the minimally invasive anterior approach surgery.

Comparison of anterior and posterior approaches for treatment of traumatic cervical dislocation combined with spinal cord injury: Minimum 10-year follow-up

Anterior reduction and interbody fusion fixation has not been compared directly with posterior reduction and short-segmental pedicle screw fixation for lower cervical dislocation, and so consensus is lacking as to which is the optimal method. The purpose of this paper is to compare long-term outcomes of the anterior versus posterior approach for traumatic cervical dislocation with spinal cord injury. One hundred and fifty-nine patients could be followed for more than 10 years (follow-up rate 84.1%). Ninety-two patients underwent anterior reduction and interbody fusion and fixation, and 67 patients underwent posterior reduction and short-segmental pedicle screw fixation. Japanese Orthopaedic Association (JOA) scores, the Neck Disability Index (NDI), the American Spinal Injury Association grading (ASIA), Odom’s criteria, cervical kyphosis, operative parameters, and surgical or post-operative complications were evaluated. Patients were followed for 10 to 17 years. There was no significant difference in main JOA scores, NDI scores or ASIA scores between the two groups at follow-up. The posterior approach was associated with greater loss of alignment by two years (P = 0.012) and at final follow-up (P < 0.001). The posterior approach group had more blood loss (P < 0.001), longer operation times (P < 0.001), longer hospital stays (P < 0.001) and fewer complications than the anterior approach group. The anterior approach is better than the posterior approach for preserving cervical lordosis, which is associated with a better long-term effect.

Evaluation of outcome of posterior decompression and instrumented fusion in thoracolumbar fractures

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The fractures of the thoracolumbar junction are the most common injuries of the vertebral column. Fall from a height and road traffic accidents are the main causes of injury. The present study aims to evaluate the functional, neurological and radiological outcome of the posterior decompression and instrumented fusion in operated patients with thoracolumbar fractures.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; In this retrospective and prospective study, a cohort of 30 patients with thoracolumbar fractures, classified by thoracolumbar injury classification and severity (TLICS) scoring system, underwent posterior decompression and pedicle screw fixation from January 2013 to August 2018 were included. Patients were assessed functionally (ODI score), neurologically (MRC grading) and radiologically (kyphotic angle) preoperatively and at 6 weeks, 3 months, 6 months and 12 months post-operatively.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The mean ODI score improved from 87.40 pre-operatively to 13.33 at final follow-up (p value 0.001). The mean kyphotic angle decreased from 24.37 degrees preoperatively to 9.87 degrees postoperatively (p value 0.001) with mean loss of correction of 1.16 degrees at final follow-up. Hip flexors and knee extensors improved from a mean preoperative value of 2.60 to 4.83 at final follow-up (p value 0.001). Similarly, ankle dorsiflexors, long toe extensors and ankle plantar flexors improved from mean preoperative value of 2.53, 2.50 and 2.60 to 3.93, 3.80 and 4.73 at final follow-up, respectively (p value 0.001).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Posterior decompression and instrumented fusion is a safe and effective surgical option in patients with thoracolumbar fractures. TLICS scoring system has a prognostic value and helps in determining the prognosis in these patients.&lt;/p&gt;

Application of oblique lumbar interbody fusion for lumbar intervertebral pyogenic infection

Objective To investigate the safety, key techniques and clinical efficacy of OLIF (oblique lumbar interbody fusion) corridor combined with lumbar intervertebral debridement, fusion with two interbody and internal fixation for the treatment of single-level lumbar pyogenic spondylodiscitis. Methods From February 2016 to March 2017, data of 12 patients with single-level lumbar intervertebral pyogenic infection diagnosed in our hospital who had undergone oblique lumbar interbody fusion with two interbody and posterior pedicle screw fixation via Wiltse approach were retrospectively analyzed. Among them, there were 10 males and 2 females, aged from 49 to 79 years, with an average age of 65.4±9.5 years. The white blood cells (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded and analyzed before operation and at the last follow-up. Lumbar pain was assessed by visual analogue acale (VAS), Oswestry disability index (ODI), and clinical efficacy was assessed by the MOS 36-item short-form health survey (SF-36) and Kirkaldy-Willis criteria. The hospitalization time, operation time, intraoperative blood loss, pathological reports, etiological results and complications were recorded. Disc height (DH), segmental angle (SA) and Lumbar Lordosis (LL) were measured before operation and at the last follow-up. The fusion time was recorded. Paired t-test and ANOVA was used for data analysis. Results All patients underwent surgery successfully, including 6 cases using two titanium meshes and 6 cases using two autologous tricortical iliac bones. Pathogenic culture was positive in 10 cases, with a positive rate of 83.3%, including 4 cases of streptococcus, 4 cases of Staphylococcus aureus, 1 case of Escherichia coli, and 1 case of Klebsiella pneumoniae. All patients were followed up for 16.1±5.1 months. At the last follow-up, WBC ([6.25±2.02] ×109/L) was lower than that before operation ([4.89±1.28] ×109/L), CRP (preoperation 58.73±52.56 mg/L vs postoperation 8.48±8.79 mg/L) and ESR (preoperation 51.88±19.04 mm/1 h vs postoperation 9.25±5.50 mm/1 h) were significantly lower (P< 0.01). The VAS score was preoperation 6.67±1.63 and postoperation 1.50±0.55, ODI score was preoperation 72.57%±3.41% and postoperation 18.00%±2.31%, and both were significantly lower postoperatively (P < 0.01). SF-36 score (preoperation 56.33±4.93 vs postoperation 73.73±5.86) was significantly higher (P< 0.01) respectively. The postoperative height of intervertebral space ([11.68±2.64] mm) was significantly higher than that before operation ([5.18±1.58] mm). The disc height at the last follow-up was (11.22±2.25) mm, and the loss rate was 1.89% compared with that of the immediate postoperatively; The postoperative lumbar lordosis angle (32.89°±14.52°) was significantly increased compared with that of the preoperative (24.16°±13.49°), and maintained well at the last follow-up (32.27°± 14.21°); The postoperative segmental angle (10.8°±8.51°) was significantly increased compared with that of the preoperative (5.81°±7.44°), and maintained well at the last follow-up (9.94°±7.87°). The fusion time ranged from 6 to 16 months, with an average of 9.2±3.5 months. The clinical efficacy was excellent in 10 cases (83.3%) and good in 2 cases (16.7%). The excellent and good rate was 100%. One case of pulmonary infection and pulmonary embolism occurred 2 days after operation, and recovered after use of antibiotics and anticoagulation treatment in ICU; one case of intramuscular venous thrombosis was found 1 day after operation, and recovered after anticoagulation treatment; no loosening of internal fixation was found, and no complications related to OLIF corridor occurred. Conclusion The treatment of single-level lumbar intervertebral pyogenic infection with OLIF corridor combined with lumbar intervertebral debridement, fusion with two interbody and internal fixation has the advantages of less blood loss, shorter operation time, more direct clearance of intervertebral space and left paravertebral focus, no disturbance of intraspinal canal and posterior structure, higher positive rate of etiology detection, shorter bedrest time and better restore of disc height and lumbar lordosis after operation. What’s more, the fusion rate is high and the clinical efficacy is satisfactory. Key words: Lumbar vertebrae; Infection; Spinal fusion