Clinically relevant biomechanical properties of three different fixation techniques of the upper instrumented vertebra in deformity surgery

Nevzati, Edin; Moser, Manuel; Dietz, Nick; Yaszay, Burt; Lenke, Lawrence G.; Farshad, Mazda; Arvind, Varun; Cho, Samuel K.; Spiessberger, Alexander

doi:10.1007/s43390-022-00506-8

Cited by 2 publications

(1 citation statement)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transpedicular screws are a mainstay for the stabilization of the thoracolumbar spine and have demonstrated superior pullout strength given biomechanical torque and cortical interface. [ 1 2 3 4 5 ] To minimize radiation exposure to the patient, operating room time, and health-care costs, freehand techniques for pedicle screws of thoracic and lumbar levels are well-described. [ 6 7 ] Thoracic transpedicular screws are often cited as some of the most challenging levels for freehand pedicular screw placement with the lowest accuracy and most frequent breach complications.…”

Section: Introductionmentioning

confidence: 99%

Consistent anatomical relationships of pedicle, lamina, and superior articulating process in severe idiopathic scoliosis allow for safe freehand pedicle screw placement: A proof-of-concept technical study

Dietz,

Spiessberger

2024

Journal of Craniovertebral Junction and Spine

Self Cite

View full text Add to dashboard Cite

Introduction: Transpedicular screw placement has superior pullout strength compared to alternative forms of spinal fusion and is often performed in deformity correction surgery with navigation for optimal accuracy and reliability. Freehand technique for pedicle screws minimizes operation time and radiation exposure without fluoroscopy but is not widely adopted given the challenge of difficult anatomical corridors and accurate placement, especially in idiopathic scoliosis and advanced deformity. We used a computer-generated model to assess a proof-of-concept and anatomical feasibility of a freehand screw technique in severe scoliosis. Methods: Three-dimensional (3D) reconstructions of vertebra from a sample of two male patients with severe idiopathic scoliosis deformity (1 thoracic and 1 lumbar) with Cobb angles of 100° were used for planned placement of 17 levels of thoracolumbar (6.5 mm × 45 mm) pedicle screws. 3D reconstruction of each vertebra was created and measurements of screw entries and trajectories were reproduced with a 3D slicer software image computing platform. Results: Accurate transpedicular screw placement is possible with anatomical landmarks based on the 3D reconstructed vertebral levels. A series of 5 figures were assembled to demonstrate sagittal, coronal, and axial planes and key anatomical landmarks and trajectories of thoracic and lumbar freehand pedicle screws in severe idiopathic scoliosis. Conclusions: Anatomical landmarks for freehand transpedicular screw placement (between pedicle, lamina, and superior articulating process) are constant and reliable in severe idiopathic scoliosis as evidenced by 3D computer modeling. Preoperative computed tomography modeling may assist appropriate screw entry and trajectory based on anatomical landmarks for spine surgeons, and guide freehand technique for screw placement in adolescent idiopathic scoliosis.

show abstract