Abdallah A. Abd El-AzizAl-Azhar University, Egypt
Title: A comparative study of pedicle screw fixation in dorsolumbar spine by freehand versus image-assisted technique
Background: Pedicle screw instrumentation has been used to stabilize the thoracolumbar spine for several decades. Although pedicle screws are originally placed via a freehand technique, there has been a movement in favor of pedicle screw placement with the aid of imaging.
Objective: To evaluate the safety and accuracy of pedicle screws placement with a freehand technique versus image-assisted technique.
Patients and methods: Patients of this study were divided into two groups: Free-hand group (group I). 18 patients and 108 screws and image assisted (group II) 32 patients and 264 screws). There were mainly for spondylolisthesis, fractures and deformity from March 2019 to November 2020 at Al-Azhar University Hospitals. Incidence and extent of cortical breach by misplaced pedicle screw was determined by a review of postoperative computed tomography (CT) images.
Results: A total of 50 patients received 372 free-hand and image assisted placed pedicle screws in the thoracic and lumbar spine. In free hand technique, a total of 8 screws (3.7%) were identified as breaching the pedicle laterally in 4 patients, and 4 screws (4.4%) breaching medially in 2 patients. In image assisted technique, a total of 14 screws (5.3%) were identified as breaching the pedicle laterally in 3 patients and 2 screws (0.75%) breaching medially in one patient. Upper thoracic spine was the most frequent location of screw breach (10.8%). The accuracy rate in our work was 89%% in the free-hand group compared to 94% in the image assisted technique group (p < 0.01).
Conclusion: Freehand technique was as good as the image-assisted technique in comparison to safety and accuracy, using both techniques together this can result in high accuracy and efficacy that can reach up to 100%.