Validation of a patient-specific finite element analysis framework for identification of growing rod-failure regions in early onset scoliosis patients.

Purpose: Growing rods are the gold-standard for treatment of early onset scoliosis (EOS). However, these implanted rods experience frequent fractures, requiring additional surgery. A recent study by the U.

Biomechanical Effects of Thoracic Flexibility and Stiffness on Lumbar Spine Loading: A Finite Element Analysis Study.

Objective: To determine the effects of thoracic stiffness on mechanical stress in the lumbar spine during motion.

Methods: To evaluate the effect of preoperative thoracic flexibility, stiff and flexible spine models were created by changing the material properties of ligaments and discs in the thoracic spine. Total laminectomy was performed at L4/5 in stiff and flexible models.

Resisting subsidence with a truss Implant: Application of the "Snowshoe" principle for interbody fusion devices.

The primary objective was to compare the subsidence resistance properties of a novel 3D-printed spinal interbody titanium implant versus a predicate polymeric annular cage. We evaluated a 3D-printed spinal interbody fusion device that employs truss-based bio-architectural features to apply the snowshoe principle of line length contact to provide efficient load distribution across the implant/endplate interface as means of resisting implant subsidence. Devices were tested mechanically using synthetic bone blocks of differing densities (osteoporotic to normal) to determine the corresponding resistance to subsidence under compressive load.

C1-C2 arthroplasty for craniovertebral junction instability: A preliminary proof of concept in human cadavers.

Background: The atlantoaxial complex contributes to significant neck movements, especially the axial rotation. Its instability is currently treated with various C1-C2 fusion techniques. This however, considerably hampers the neck movements and affects the quality of life; a C1-C2 motion preserving arthroplasty could potentially overcome this drawback.

The Transverse Process Trajectory Technique: An Alternative for Thoracic Pedicle Screw Implantation-Radiographic and Biomechanical Analysis.

Background: This study evaluates the accuracy, biomechanical profile, and learning curve of the transverse process trajectory technique (TPT) compared to the straightforward (SF) and in-out-in (IOI) techniques. SF and IOI have been used for fixation in the thoracic spine. Although widely used, there are associated learning curves and symptomatic pedicular breaches.

A new lumbar fixation device alternative to pedicle-based stabilization for lumbar spine: cadaver investigation.

To evaluate the stability provided by a new bilateral fixation technique using an investigation for posterior lumbar segmental instrumentation. Experimental cadaver study. In this study, we propose an alternative technique for a posterior lumbar fixation technique called "inferior-oblique transdiscal fixation" (IOTF).

Does Spanning a Lateral Lumbar Interbody Cage Across the Vertebral Ring Apophysis Increase Loads Required for Failure and Mitigate Endplate Violation.

Study Design: Randomized Biomechanical Cadaveric Study-Level II.

Objective: We aimed to elucidate that placing lateral lumbar interbody cages that span the stronger ring apophysis will require increasing loads for failure, decreasing rates of subsidence, regardless of bone density or endplate integrity.

Summary Of Background Data: There are several reports regarding the rates and grades of cage subsidence when utilizing the lateral lumbar interbody fusion technique.

Adjacent-Level Hypermobility and Instrumented-Level Fatigue Loosening With Titanium and PEEK Rods for a Pedicle Screw System: An In Vitro Study.

Adjacent-level disease is a common iatrogenic complication seen among patients undergoing spinal fusion for low back pain. This is attributed to the postsurgical differences in stiffness between the spinal levels, which result in abnormal forces, stress shielding, and hypermobility at the adjacent levels. In addition, as most patients undergoing these surgeries are osteoporotic, screw loosening at the index level is a complication that commonly accompanies adjacent-level disease.

Morphological changes of the caudal cervical intervertebral foramina due to flexion-extension and compression-traction movements in the canine cervical vertebral column.

Background: Previous studies in humans have reported that the dimensions of the intervertebral foramina change significantly with movement of the spine. Cervical spondylomyelopathy (CSM) in dogs is characterized by dynamic and static compressions of the neural components, leading to variable degrees of neurologic deficits and neck pain. Studies suggest that intervertebral foraminal stenosis has implications in the pathogenesis of CSM.

Effects of flexion and extension on the diameter of the caudal cervical vertebral canal in dogs.

Objective: To quantify changes in the diameter of the vertebral canal with flexion and extension in the cervical vertebral column.

Study Design: Cadaveric biomechanical study.

Sample Population: Cadaveric canine cervical vertebral column (n = 16 dogs).