Anatomic evaluation and relationship between the lumbar pedicle and adjacent neural structures: an anatomic study

Area of Science:

• Orthopedic Surgery
• Neurosurgery
• Anatomy

Background:

• Transpedicular spinal fixation is gaining attention globally.
• Ensuring safety and efficacy through accurate screw placement is vital for orthopedic surgeons.
• Understanding the anatomical relationships around the lumbar pedicle is key to preventing neural complications.

Purpose of the Study:

• To quantitatively analyze the anatomical relationships between the lumbar pedicle and adjacent neural structures.
• To identify high-risk zones for neural injury during transpedicular screw insertion.
• To provide data for improving the safety of lumbar pedicle screw placement.

Main Methods:

• Study involved ten adult cadavers.
• Lumbar pedicles, dural sac, and nerve roots were exposed after removing laminae and facets.
• Key distances including interpedicular distance (IPD) and distances to nerve roots and dural sac were measured.

Main Results:

• Average distances from the lumbar pedicle to the dural sac ranged from 1.29-1.56 mm.
• Distances to superior and inferior nerve roots ranged from 4.12-5.52 mm and 1.10-1.06 mm, respectively.
• Statistically significant differences in IPD, PSRD, and PDSD were noted between L5 and other lumbar levels.

Conclusions:

• The L5 level appears safer for pedicle screw insertion compared to other lumbar levels.
• Improper medial or caudal placement of pedicular screws poses a significant risk of injury to the dural sac and inferior nerve root.
• Precise anatomical knowledge is essential for minimizing neural injury during transpedicular fixation.