[External fixators in temporary spinal stabilization. Radiographic anatomy of the lumbar pedicles]

Area of Science:

• Orthopedic Surgery
• Spinal Fusion Techniques
• Biomechanical Analysis

Background:

• External spinal fixation is a surgical technique employed for lumbar spine fusion and managing lumbosacral pain.
• Percutaneous screw implantation necessitates precise localization using anterior-posterior X-rays, with the pedicle oval as the primary landmark.
• Existing methods may lead to pedicle perforation due to anatomical variations between the arch root and the halo.

Purpose of the Study:

• To evaluate the efficacy of external spinal fixation in enhancing lumbar spine fusion rates.
• To determine the optimal method for screw placement during percutaneous implantation to avoid complications.
• To investigate the anatomical accuracy of pedicle localization using X-ray guidance.

Main Methods:

• Cadaver studies were conducted to analyze the anatomical relationship between the pedicle, arch root, and halo.
• Radiographic assessment using anterior-posterior X-rays was performed to evaluate screw trajectory and potential perforation.
• External spinal fixation was applied in a cohort of patients requiring lumbar fusion.

Main Results:

• Cadaver studies revealed that the pedicle's root of the arch and the halo are not identical.
• Reliance on the midpoint of the halo is critical for accurate screw placement, preventing medial pedicle perforation.
• External spinal fixation demonstrated a markedly enhanced fusion rate of the lumbar spine.

Conclusions:

• Accurate pedicle screw placement, guided by the halo midpoint in X-rays, is essential for safe external spinal fixation.
• This technique significantly improves lumbar spine fusion rates.
• External spinal fixation offers a viable solution for indicated spinal fusion and pain management.