CT SCAN ASSESSMENT OF THE PEDICLES: APPLICATION IN THE SURGICAL TREATMENT SCOLIOSIS
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Abstract
Objective: To evaluate the value of multi-slice computed tomography (MSCT) in preoperative pedicle assessment and the clinical efficacy of the pedicle screw funnel technique in the treatment of severe scoliosis.
Patients and Methods: A retrospective study was conducted on 32 patients (24 females, 8 males; mean age 17.9 years) with severe scoliosis who underwent posterior spinal fusion using all-pedicle-screw constructs between 2006 and 2010. Preoperative MSCT scans from T1 to L5 were performed to measure pedicle dimensions, vertebral rotation, and vertebral body depth. Postoperative screw positions were evaluated via MSCT using the RAO classification.
Results: A total of 547 pedicle screws were placed. Ideal screw position (RAO Grade 0) was achieved in 82% (450 screws); Grade 1 in 7.6% (42 screws); Grade 2 in 6.2% (34 screws); and Grade 3 in 3.8% (21 screws). Revision surgery was performed in 6 patients for 15 Grade 3 screws (2.7% of total), yielding optimal postoperative positioning, while 7 Grade 3 screws required no intervention due to a lack of clinical symptoms. Misplaced screws were primarily located in the concave thoracic spine or the upper convex thoracic spine where pedicles were extremely small or absent (13 pedicles were absent in the T2–T6 region, representing 2.37%).
Conclusion: Preoperative MSCT is a powerful tool for surgical planning, enabling surgeons to navigate anatomical deformities, determine optimal screw trajectories, and select appropriate screw sizes. Combining MSCT with the funnel technique ensures high placement accuracy and minimizes neurovascular complications in severe scoliosis correction.
Keywords
Severe scoliosis, Pedicle screws, Funnel technique, RAO classification, Multi-slice computed tomography (MSCT)
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References
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