INTRODUCTION: The objective of this study was to develop a novel, patient-specific, navigational template for thoracic pedicle screw placement. METHODS: Twenty thoracic cadaver specimens were randomly divided into two groups of 10: the navigational template group and the free-hand group. A volumetric CT scan was performed on each thoracic vertebra, and a three-dimensional reconstruction model was generated. A drill template was designed with a surface that was the inverse of the posterior vertebral surface. Each drill template and its corresponding vertebra were manufactured using a rapid prototyping technique and tested for violation. Two hundred and forty screws were implanted into the thoracic spines and the positions of the screws were evaluated. RESULTS: Two hundred and forty thoracic screws were inserted using either the navigational template method or the free-hand method. The accuracy rate and incidence of risk for setting thoracic pedicle screws differed statistically between the two methods (P < 0.05): The navigational template method had a higher accuracy rate and a lower incidence of risk than the free-hand method. Moreover, the free-hand method had a significant learning curve, whereas a learning curve for the navigational template method was not obvious. CONCLUSION: We have developed a novel, patient-specific, navigational template for thoracic pedicle screw placement with good applicability and high accuracy.
INTRODUCTION: The objective of this study was to develop a novel, patient-specific, navigational template for thoracic pedicle screw placement. METHODS: Twenty thoracic cadaver specimens were randomly divided into two groups of 10: the navigational template group and the free-hand group. A volumetric CT scan was performed on each thoracic vertebra, and a three-dimensional reconstruction model was generated. A drill template was designed with a surface that was the inverse of the posterior vertebral surface. Each drill template and its corresponding vertebra were manufactured using a rapid prototyping technique and tested for violation. Two hundred and forty screws were implanted into the thoracic spines and the positions of the screws were evaluated. RESULTS: Two hundred and forty thoracic screws were inserted using either the navigational template method or the free-hand method. The accuracy rate and incidence of risk for setting thoracic pedicle screws differed statistically between the two methods (P < 0.05): The navigational template method had a higher accuracy rate and a lower incidence of risk than the free-hand method. Moreover, the free-hand method had a significant learning curve, whereas a learning curve for the navigational template method was not obvious. CONCLUSION: We have developed a novel, patient-specific, navigational template for thoracic pedicle screw placement with good applicability and high accuracy.
Authors: Ahmed A Aoude; Maryse Fortin; Rainer Figueiredo; Peter Jarzem; Jean Ouellet; Michael H Weber Journal: Eur Spine J Date: 2015-03-07 Impact factor: 3.134