Purpose: We present 120 patients (37 males, 83 females) affected by thoracic lumbar scoliosis, treated by posterior instrumented arthrodesis with the insertion of pedicle screws by "free hand technique", without any image guided system, radioscopy use during insertion or intraoperative neurophysiological monitoring.
Methods: Seventy-two (60%) patients have been treated by hybrid instrumentation with lumbar and thoracic screws, hooks and wires at thoracic levels, while the remaining 48 (40%) patients have used only lumbar and thoracic pedicle screws. Mean Cobb grades value of the main scoliotic curve was 73° before surgery in patients treated by hybrid instrumentation, reduced to 37.5° after surgery. In patients treated only by screws, mean Cobb grades value of the main scoliotic curve was 65°, reduced to 16° after surgery.
Results: Minimum follow up has been 3 years; mean patient age at surgery was 15 years and 4 months. We placed a total number of 1,004 pedicle screws, 487 of which at thoracic level. In 12 patients (10%) a total number of 20 screws were misplaced at postoperatory exam, without any clinical complication for the patients or consequences on the arthrodesis or on maintaining the correction of the curve.
Conclusions: In our experience pedicle screws is the method that leads to best correction and balance on vertebral bodies, with best results at distance concerning correction maintaining. Our experience shows that even at thoracic level, pedicle screws insertion by free-hand technique is safe and reliable.