Morphometric analysis of the thoracic pedicle: an anatomico-radiological study

Area of Science:

• Orthopedic Surgery
• Spinal Anatomy
• Radiology

Background:

• Accurate thoracic pedicle screw placement relies on understanding pedicle morphometric anatomy.
• Knowledge of these anatomical features is vital for surgical success and patient safety.

Purpose of the Study:

• To investigate the morphometry of thoracic spine pedicles in Indian individuals.
• To identify key anatomical landmarks for precise and safe pedicle screw insertion.

Main Methods:

• Anatomico-radiological study combined with cadaveric confirmation.
• Morphometric analysis of 720 pedicles (T1-T12) from 15 cadaveric thoracic spines and 15 CT scans.
• Evaluation included transverse/sagittal diameters, angle, chord length, and entry point landmarks.

Main Results:

• Pedicle diameter was smallest at T4, increasing caudally; 22% of T4-T6 pedicles were <4.5 mm.
• Transverse pedicle angle decreased from T1 (26.5°) to T12 (8.1°).
• Chord length increased caudally from 30.4 mm (T1) to 43.3 mm (T12); entry point was superolateral to the lamina-transverse process junction.

Conclusions:

• Pedicle diameter and chord length are essential for selecting appropriate pedicle screws.
• Pedicle angle and entry point landmarks are critical for accurate screw placement during thoracic spine surgery.