OBJECTIVE: To Evaluate by CT scan tridimensional reconstruction, malpositioning of pedicle screws in adolescent idiopathic scoliosis patients. METHODS: It was analyzed CT scan cuts of 8 patients submitted to surgical treatment in Hospital de Base de São José do Rio Preto- SP, which were performed posterior spinal fusion from T2/T4 to L4/L5, 164 screws were inserted. RESULTS: 32,9% (n=54) were malpositioned offering potential risk, which was considered 2mm deviation, 20,1% (n=33) lateral invasion, 9,1% (n=15) medial invasion, 3,6% (n= 6) anterior invasion. From those malpositioned screws 46% (n=25) were in concavity, 35% (n=19) in convexity and 19% (n=10) were nearby curve. CONCLUSION: Acceptable invasion boundaries were not well determined, and also measurements methods are not standardized. The "free hand" technique proved safe, besides pedicle violation. Pre-Op CT Scan showed helpful in surgery planning and avoiding complications.
Scoliosis; Bone Screws; Spinal Fusion
