Study Design: In vitro study using porcine spines instrumented with pedicle screw and rod fixation.
Objectives: To determine the intradiscal pressure (IDP) changes with the use of dynamic and rigid pedicle screw systems in simulated spinal fusion.
Summary Of Background Data: The intervertebral discs are prone to injury under conditions of altered IDP. The effects of instrumentation with dynamic pedicle screw systems on IDP have not been clearly delineated.
Methods: A 2-level posterior instrumentation was applied to fresh porcine spinal segments (n=16). Dynamic and rigid pedicle screw constructs along with uninstrumented (n=6) spinal segments as controls were tested. The spinal segments were subjected to 24,000 cycles of flexion compression loading at 5 Hz. IDP within the instrumented (L2-L3 and L3-L4) and adjacent (L1-L2 and L4-L5) discs were measured using a pressure transducer needle. Results were recorded at 6000 cycle intervals.
Results: Instrumentation increased IDP. Within the instrumented levels, the greatest increase in IDP was found at the L2-L3 disc. Here, after 24,000 loading cycles, IDP for spines instrumented with mobile screws was 6.8 times higher than that of uninstrumented spines whereas for rigid screws the factor was 9.1. For the L3-L4 cases, the presence of instrumentation increased IDP by factors of 1.7 and 2.7 for mobile and rigid screws, respectively. In the uninstrumented levels, IDP at L1-L2 and L4-L5 was lower with mobile screws. These were statistically significant at for L1-L2 (24,000 cycles, P=0.008) and L4-L5 level (12,000, 18,000, and 24,000 cycles, P<0.04 in all cases).
Conclusions: Of the 2 types, mobile screws produced the least increase in IDP. This feature might be beneficial for the fusion process while at the same time prevent secondary pathology such as premature disc degeneration and facet joint pathology due to excessive disc pressures.
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http://dx.doi.org/10.1097/BSD.0b013e3180ca7116 | DOI Listing |
J Neurosurg Spine
January 2025
1Department of Spine Surgery, Hospital for Special Surgery, New York.
Objective: When creating minimally invasive spine fusion constructs, accurate pedicle screw fixation is essential for biomechanical strength and avoiding complications arising from delicate surrounding structures. As research continues to analyze how to improve accuracy, long-term patient outcomes based on screw accuracy remain understudied. The objective of this study was to analyze long-term patient outcomes based on screw accuracy.
View Article and Find Full Text PDFBrain Spine
May 2024
Goettingen Medical University, Department of Trauma Surgery, Orthopedics and Plastic Surgery, Robert-Koch-Str. 40, D-37099, Goettingen, Germany.
Introduction: As medical education becomes more complex, the demand for advanced teaching and training methods has grown. Technological advancements have opened up new possibilities, particularly in the realm of virtual reality (VR) simulations for training.
Research Question: Our prospective, randomized pilot study aims to assess whether a novel VR-based 3D training platform can effectively teach the knowledge and skills needed for complex spinal surgery, specifically pedicle screw placement.
Eur Spine J
January 2025
Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing, China.
Purpose: To describe a novel alternative technique for C2 fixation under the concept of atlantoaxial joint distraction and fusion with intra-articular Cages, and to report its preliminary clinical outcomes.
Methods: Eighteen patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial joint distraction and fusion with intra-articular Cages. All patients had hypoplasia of the C2 isthmus prohibiting insertion of the pedicle screw.
BMC Geriatr
January 2025
Department of Neurosurgery, Yonsei University College of Medicine, 50, Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, Republic of Korea.
Background: Comparative studies of posterior lumbar interbody fusion with cortical bone trajectory and pedicle screw in older patients, particularly in those aged ≥ 80 years, are rare. This study aimed to retrospectively analyze the clinical and surgical outcomes following posterior lumbar interbody fusion with pedicle screw fixation compared to cortical bone trajectory in patients aged ≥ 80 years with degenerative lumbar spine disease.
Methods: We included 68 patients aged ≥ 80 years who underwent degenerative lumbar spinal surgery at our spine center between January 2011 and December 2020.
Med Leg J
January 2025
Department of Neurosurgery, Tufts Medical Center, Tufts University School of Medicine, Boston, USA.
Spine surgery is highly litigious; misplaced screws and intraoperative neuromonitoring frequently feature in lawsuits. Intraoperative neuromonitoring aims to prevent injury but its standards are debated, and literature suggests its benefits are mixed. We surveyed its use among neurosurgeons from the Congress of Neurological Surgeons with Pearson's chi-square test applied to analyse data within R.
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