How Accurately do Inexperienced Surgeons Place Thoracic Pedicle Screws with the Free Hand Technique?
Purpose: To evaluate with real time direct observation what are the common errors made and whether these errors are recognized while they are occurring when inexperienced surgeons learn to place thoracic pedicle screws. Methods: Three orthopaedic resident surgeons inexperienced in the straight ahead freehand technique received an introductory teaching session and utilized published visual charts (Lenke 2004). Six adult spines were used to harvest intact vertebral body specimens with rib heads removed. Each vertebral body was mounted on a clear plexiglass frame with only the posterior surface anatomy visible to the surgeon. The resident surgeon verbalized all perceived anatomical violations. An observer recorded in real time the accuracy of gearshift probe, flexible probe, tap and screw placement. A critically perforated screw was defined as greater than 2.0 mm outside the confines of the pedicle wall. Results: 137 pedicles in 68 intact vertebral body specimens were instrumented with ei
