Search Results (55)

Pedicle screw fixation is a critical technique for stabilizing lumbar fractures in canines, yet the biomechanical implications of insertion angles remain underexplored. This study aims to identify optimal screw trajectories by analyzing stress distribution and deformation patterns in beagle lumbar segments (L6-L7) using finite element analysis (FEA). A 3D finite element model was reconstructed from CT scans of a healthy beagle, incorporating cortical/cancellous bone, intervertebral disks, and cartilage. Pedicle screws (2.4 mm diameter, 22 mm length) were virtually implanted at angles ranging from 45° to 65°. A 10 N vertical load simulated standing conditions. Equivalent stress and total deformation were evaluated under static loading. The equivalent stress occurred at screw–rod junctions, with maxima at 50° (11.73 MPa) and minima at 58° (3.25 MPa). Total deformation ranged from 0.0033 to 0.0064 mm, with the highest at 55° and the lowest at 54°. The 58° insertion angle demonstrated optimal biomechanical stability with minimal stress concentration, with 56–60° as a biomechanically favorable range for pedicle screw fixation in canine lumbar fractures, balancing stress distribution and deformation control. Future studies should validate these findings in multi-level models and clinical settings. Full article

Background: Traumatic fractures of the cervical spine pose significant challenges in management, particularly in young patients, where preserving mobility is crucial. Patient Characteristics: A 30-year-old woman presented with a C3 lateral mass and pedicle fracture following a motor vehicle collision. Initial conservative management with a rigid cervical collar for three months failed to reduce the diastasis, and the debilitating neck pain worsened. Preoperative imaging confirmed fracture instability without spinal cord compression. Intervention and Outcome: Preoperative screw trajectory planning was conducted with the My Spine MC system (Medacta), and fine-tuning was achieved on a 3D-printed model of the vertebra. A posterior midline approach was employed to expose the C3 vertebra, and a Herbert screw was inserted under fluoroscopic guidance. Imaging at three months demonstrated significant fracture reduction and early bone fusion. The patient achieved substantial improvement in functional mobility without complications. Conclusion: Herbert screw fixation holds potential as a less-invasive alternative to conventional posterior stabilization for selected cervical fractures. This technical note provides the reader with the required information to support surgical planning and execution. Full article

Pedicle screw fixation is a common spinal surgery technique, but concerns remain about stability when screws are malpositioned. Traditional in vitro pull-out tests assess anchorage but lack physiological accuracy. This study examined the stability of correctly placed and intentionally malpositioned pedicle screws on forty vertebrae from five cadavers. Optimal screw paths were planned via CT scans and applied using 3D-printed guides. Four malposition types—medial, lateral, superior, and superior-lateral—were created by shifting the original trajectory. A custom setup applied three consecutive cycles of tensile and compressive load from 50 N to 200 N. Screw inclination under load was measured with a 3D optical system. The results showed increasing screw inclination with higher forces, reaching about 1° at 50 N and 2° at 100 N, similar in both load directions. Significant differences in inclination were only found at 100 N tensile load, where malpositioned screws showed a lower inclination. Overall, malpositioning had no major effect on screw loosening. These findings suggest that minor deviations in screw placement do not significantly compromise mechanical stability. Clinically, the main concern with malpositioning lies in the potential for injury to nearby structures rather than reduced screw fixation strength. Full article

This study aimed to develop a novel modular pedicle screw system incorporating an elliptical sleeve to conform the pedicle’s elliptical cross-section and enhance fixation strength with mechanical stability. The biomechanical evaluation was conducted based on fundamental mechanics principles, followed by a finite element (FE) analysis to assess stress distribution under compressive and torsional loads. Subsequently, mechanical testing was performed to evaluate static and fatigue bending performance and in vitro biomechanical fatigue in porcine vertebrae by pull-out testing after 5000 and 100,000 cycles to assess fixation stability. The FE analysis demonstrated that the elliptical sleeve design improved bending resistance by 1.21× and torsional resistance by 1.91× compared to conventional cylindrical screws. Mechanical testing revealed greater bending/torsion stiffness and fatigue resistance, with the elliptical sleeve screw withstanding 5 million cycles at 235.4 N, compared to 175.46 N for cylindrical screws. Biomechanical pull-out testing further confirmed significantly higher retention strength after 100,000 cycles (1229.75 N vs. 867.83 N, p = 0.0101), whereas cylindrical screws failed prematurely at 10,663 cycles due to excessive displacement (>2 mm). The elliptical sleeve pedicle screw system demonstrated enhanced fixation strength, reduced micromotion, and superior fatigue resistance, making it a promising alternative to conventional pedicle screws for improving long-term spinal fixation stability. Full article

Background/Objectives: Degenerative lumbar spine conditions are a major cause of disability, particularly in elderly patients or those with comorbidities. Surgical treatment often combines decompression and stabilization to address pain and instability. Pedicle screws are the gold standard for stabilization but pose challenges in patients with compromised bone quality. Interspinous devices have emerged as a less invasive alternative, but comparative studies are limited. This study aimed to compare clinical and surgical outcomes of lumbar decompression with stabilization using pedicle screws versus interspinous devices. Methods: A retrospective cohort study was conducted on patients who underwent lumbar decompression with either pedicle screw fixation or interspinous device stabilization at Mater Olbia Hospital between February 2020 and February 2023. Outcomes were evaluated using VAS for back and leg pain, SF-36 for quality of life, EQ-5D, and SCL-90 for psychological factors. Statistical analysis included paired t-tests, chi-square tests, and multivariate regression. Results: A total of 728 patients were included. The interspinous device group consisted of older patients with higher comorbidity burdens (mean age: 68.4 vs. 59.2 years, p < 0.001). Surgical time and incision size were significantly shorter in the interspinous group (p < 0.001), and no postoperative complications were reported, compared to 3.5% in the pedicle screws group (p < 0.05). Both groups demonstrated significant improvements in pain (VAS), quality of life (SF-36, EQ-5D), and psychological outcomes (SCL-90). Somatization and paranoid ideation were significant predictors of worse postoperative pain, particularly in the pedicle screws group. No significant differences in quality-of-life improvements were observed between the groups. Conclusions: Both stabilization techniques are effective for lumbar spine surgery, with interspinous devices offering a safer and less invasive option for high-risk patients. Psychological factors significantly influence pain outcomes, underscoring the need for a comprehensive approach addressing both physical and psychological aspects to optimize patient recovery. Full article

Spinopelvic dissociation is a highly unstable orthopedic injury with a growing incidence worldwide. Operative treatment classically involves an open lumbopelvic fusion and sacroiliac stabilization, which carries high perioperative morbidity and mortality in a frail patient population. Advancements in spinal navigation, robotics, and minimally invasive surgery (MIS) techniques now allow these fracture patterns to be treated entirely percutaneously through small incisions. These incisions are just large enough to accommodate pedicle screw guides and enable the placement of lumbopelvic instrumentation, with rods being passed subfascially across pedicle screws and extending caudally to iliac fixation. This contrasts with the open midline approach, which requires more extensive soft tissue dissection and results in increased blood loss compared to percutaneous techniques. Modern imaging techniques, including CT navigation and robotics, facilitate the precise placement of sacral S2AI screw instrumentation in both open and percutaneous methods, all while safely avoiding previously placed trans-sacral fixation and other existing hardware, such as acetabular screws. Trans-sacral screws are typically percutaneously inserted first by the orthopedic trauma service, utilizing inlet, outlet, and lateral sacral fluoroscopic guidance to navigate the limited available corridor. With the advent of MIS techniques, trauma patients can now benefit from faster postoperative rehabilitation, minimal blood loss, decreased pain, and quicker mobilization. This article will review current concepts on spinopelvic anatomy, fracture patterns, indications for treatment, and current concepts for minimally invasive percutaneous lumbopelvic fixation, and it will present illustrative examples. Full article

Current standard of care treatment for patients with spine tumors includes multidisciplinary approaches, including the following: (1) surgical tumor debulking, epidural spinal cord decompression, and spine stabilization techniques; (2) systemic chemo/targeted therapies; (3) radiation therapy; and (4) surveillance imaging for local disease control and recurrence. Titanium pedicle screw and rod fixation have become commonplace in the spine surgeon’s armamentarium for the stabilization of the spine following tumor resection and separation surgery. However, the high degree of imaging artifacts seen with titanium implants on postoperative CT and MRI scans can significantly hinder the accurate delineation of vertebral anatomy and adjacent neurovascular structures to allow for the safe and effective planning of downstream radiation therapies and detection of disease recurrence. Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) spine implants have emerged as a promising alternative to titanium due to the lack of artifact signals on CT and MRI, allowing for more accurate and safe postoperative radiation planning. In this article, we review the tenants of the surgical and radiation management of spine tumors and discuss the safety, efficacy, and current limitations of CFR-PEEK spine implants in the multidisciplinary management of spine oncology patients. Full article

The spine is a complex structure critical for stability, force transmission, and neural protection, with spinal fractures and spondylolisthesis posing significant challenges to its integrity and function. Spinal fractures arise from trauma, degenerative conditions, or osteoporosis, often affecting transitional zones like the thoracolumbar junction. Spondylolisthesis results from structural defects or degenerative changes, leading to vertebral displacement and potential neurological symptoms. Diagnostic and classification systems, such as AO Spine and TLICS, aid in evaluating instability and guiding treatment strategies. Advances in surgical techniques, including minimally invasive approaches, pedicle screws, interbody cages, and robotic-assisted systems, have improved precision and recovery while reducing morbidity. Vertebral augmentation techniques like vertebroplasty and kyphoplasty offer minimally invasive options for osteoporotic fractures. Despite these innovations, postoperative outcomes vary, with challenges such as persistent pain and hardware complications necessitating tailored interventions. Future directions emphasize predictive analytics and enhanced recovery strategies to optimize surgical outcomes and patient quality of life. Full article

Study Design: This was a single-institution, retrospective cohort study. Objective: The objective of this study was to assess a surgical technique for spinal reconstruction after corpectomy, integrating an allograft/autograft within a vertebral body replacement cage linked to spinal rods via pedicle screws. This method aims to enhance biomechanical stability and promote long-term fusion without cage endcaps. Summary of Background data: Recent advancements in spinal surgery feature innovative constructs that improve healing and fusion rates. FDA-approved mesh cages provide enhanced stability and superior fusion with fewer complications. Our approach combines allografts/autografts with vertebral replacements, using a pedicle screw through the cage for significant biomechanical enhancement. Methods: Two patients undergoing cervical and lumbar spinal reconstructions due to different pathologies were selected. The surgical technique involved shaping the allograft/autograft to fit precisely within the cage, extending beyond its ends to facilitate fusion at both ends, and securing the construct to the spinal rods with pedicle screws for added stability. Patient outcomes were assessed based on post-operative stability, fusion rates, and the presence of any complications. Results: Both cases successfully utilized the technique, achieving stabilization and fusion. Improvements were noted in post-operative recovery. There were no instances of cage subsidence, or any significant complications directly related to the novel construct. Conclusions: Our case series highlights a post-corpectomy reconstruction technique involving a mesh cage construct integrated with an autograft/allograft and connected to posterior instrumentation for enhanced stability. This technique was applied successfully in two cases, demonstrating its feasibility, durability, and potential to promote biological integration. Further studies with larger cohorts and extended follow-up periods are necessary to refine the approach for wider clinical use. Full article

Background: Thoracolumbar and lumbar spine injuries account for 30–60% of spinal fractures, especially at the thoracolumbar junction. Conservative treatment is recommended for stable fractures without neurological symptoms, but studies suggest surgical intervention may offer better outcomes. However, there is no consensus on the best stabilization method. Methods: This non-randomized, prospective study was conducted on 114 patients divided into groups based on the surgical technique selected: pedicle stabilization using Schanz screw constructs (Group One, n = 37) stabilization above and below the fractured vertebra using pedicle screws (Group Two, n = 32), and intermediate fixation with a pedicle screw additionally inserted into the fractured vertebra (Group Three, n = 45). Outcomes were assessed using the Cobb angle, anterior and posterior vertebral wall height, and patient quality of life via the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). X-ray imaging was performed before, during, and after surgery in the control group. Results: This statistical study showed that the location and type of injury significantly influenced the choice of short-segment stabilization method. In the case of measuring the Cobb angle and the high anterior wall, the statistical analysis showed that the best result was observed in the Schanz Group. Patients from this study group had the lowest pain and the highest efficiency. Conclusions: Schanz screw stabilization may offer superior outcomes for thoracolumbar spine injuries, providing better clinical and quality of life results compared to other methods. Full article

Objective: To evaluate the efficacy of open and percutaneous pedicle screw fixation in the treatment of thoracolumbar fractures. Methods: Online databases MEDLINE (PubMed), SCOPUS, and Cochrane were searched for English language articles published between January 2001 and December 2023, limited to articles that included the clinical and radiological outcomes of adult patients. The main outcome measures of the study were the Oswestry Disability Index (ODI), the Numeric Rating Scale (NRS) score, and the Cobb angle. Results: A total of 7 studies involving 909 patients were included; 374 (41.1%) procedures were performed with open surgery (OS), while 535 (58.9%) procedures were conducted with minimally invasive surgery (MIS). The mean value of ODI in the MIS group was 8.29% [CI 95% 4.82–11.76], compared to the other group, which was 14.22% (p-value 0.87). Patients receiving a MIS had an average NRS of 1.54 [CI95% 0.98–2.10] whilst OS had 2.31 [CI95% 1.50–3.12] (p-value 0.12). Conclusions: The percutaneous technique is equally safe and effective in resolving the deformity, but the clear advantages are represented by the reduction in blood loss, shorter operative times, a lower incidence of infection, shorter hospitalization, shorter postoperative rehabilitation, and therefore good results in terms of quality of life. Full article

This paper delves into the historical evolution of spinal surgery, focusing on the pivotal role of the Harrington rod in treating spinal deformities. Introduced in 1955, the Harrington rod marked a significant breakthrough in neurosurgery, especially for scoliosis treatment, by offering a novel approach to spinal stabilization. Through a retrospective analysis, this study examines the development and impact of the Harrington rod, highlighting Dr. Paul Harrington’s contributions to spinal surgery. His innovative technique revolutionized the management of spinal deformities, laying the groundwork for future advancements in spinal instrumentation. Despite initial skepticism, Harrington’s methods gained acceptance, significantly influencing neurosurgical practices and patient outcomes. This study also explores subsequent advancements that built on Harrington’s work, including the transition to long-segment spine constructs and the introduction of segmental pedicle screws, which allowed for more precise deformity correction. Reflecting on Harrington’s legacy, this paper acknowledges the continuous evolution of spinal surgery, driven by the interplay between clinical challenges and technological innovations. Harrington’s pioneering spirit exemplifies the ongoing pursuit of better surgical outcomes, underscoring the importance of innovation in the field of neurosurgery. Full article

(1) Background: Pelvic fractures, and particularly instabilities of the dorsal pelvic ring, are becoming increasingly prevalent, particularly in orthogeriatric patients. Spino-pelvic triangular osteosynthesis is an effective approach to achieve sufficient stabilization in vertically unstable fractures. This study compares two types of osteosynthesis: the conventional one and a novel instrumentation where the iliosacral screw is placed through a fenestrated iliac screw. (2) Methods: Sixteen artificial osteoporotic L5+pelvis models with an unstable sacral fracture have been instrumented with either an iliac screw connected with a rod to a L5 pedicle screw and an iliosacral screw (TF) or a fenestrated ilium screw connected with a rod to a L5 pedicle screw and an iliosacral screw passing through the fenestra of the iliac screw (TFS). Biomechanical testing was performed using cyclic loading until failure. (3) Results: Both configurations yielded comparable results with regard to initial stiffness, implant loosening, and cycles to failure. The TFS exhibited markedly higher values for cycles to failure and markedly lower values for loosening. However, due to the characteristics of the artificial bone model, these findings were not significant. (4) Conclusions: The novel triangular fixation systems demonstrated comparable results to the standard triangular osteosynthesis configuration. Full article

Background and Objectives: Proximal junctional kyphosis (PJK) and failure (PJF), the most prevalent complications following long-segment thoracolumbar fusions for adult spinal deformity (ASD), remain lacking in defined preventive measures. We studied whether one of the previously reported strategies with successful results—a prophylactic augmentation of the uppermost instrumented vertebra (UIV) and supra-adjacent vertebra to the UIV (UIV + 1) with polymethylmethacrylate (PMMA)—could also serve as a preventive measure of PJK/PJF in minimally invasive surgery (MIS). Materials and Methods: The study included 29 ASD patients who underwent a combination of minimally invasive lateral lumbar interbody fusion (MIS-LLIF) at L1-2 through L4-5, all-pedicle-screw instrumentation from the lower thoracic spine to the sacrum, S2-alar-iliac fixation, and two-level balloon-assisted PMMA vertebroplasty at the UIV and UIV + 1. Results: With a minimum 3-year follow-up, non-PJK/PJF group accounted for fifteen patients (52%), PJK for eight patients (28%), and PJF requiring surgical revision for six patients (21%). We had a total of seven patients with proximal junctional fracture, even though no patients showed implant/bone interface failure with screw pullout, probably through the effect of PMMA. In contrast to the PJK cohort, six PJF patients all had varying degrees of neurologic deficits from modified Frankel grade C to D3, which recovered to grades D3 and to grade D2 in three patients each, after a revision operation of proximal extension of instrumented fusion with or without neural decompression. None of the possible demographic and radiologic risk factors showed statistical differences between the non-PJK/PJF, PJK, and PJF groups. Conclusions: Compared with the traditional open surgical approach used in the previous studies with a positive result for the prophylactic two-level cement augmentation, the MIS procedures with substantial benefits to patients in terms of less access-related morbidity and less blood loss also provide a greater segmental stability, which, however, may have a negative effect on the development of PJK/PJF. Full article

Lumbar interbody fusion procedures have seen a significant evolution over the years, with various approaches being developed to address spinal pathologies and instability, including posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and lateral lumbar interbody fusion (LLIF). LLIF, a pivotal technique in the field, initially emerged as extreme/direct lateral interbody fusion (XLIF/DLIF) before the development of oblique lumbar interbody fusion (OLIF). To ensure comprehensive circumferential stability, LLIF procedures are often combined with posterior stabilization (PS) using pedicle screws. However, achieving this required repositioning of the patient during the surgical procedure. The advent of single-position surgery (SPS) has revolutionized the procedure by eliminating the need for patient repositioning. With SPS, LLIF along with PS can be performed either in the lateral or prone position, resulting in significantly reduced operative time. Ongoing research endeavors are dedicated to further enhancing LLIF procedures making them even safer and easier. Notably, the integration of robotic technology into SPS has emerged as a game-changer, simplifying surgical processes and positioning itself as a vital asset for the future of spinal fusion surgery. This literature review aims to provide a succinct summary of the evolutionary trajectory of lumbar interbody fusion techniques, with a specific emphasis on its recent advancements. Full article