Simulation workshops for surgical training of residents are becoming popular. The gold standard for teaching thoracolumbar pedicle screw placement are cadaver labs; however, the availability of human bodies is limited. The primary objective of this study was to determine if training on a synthetic bone model improves the apprenticeship of accurate pedicle screw placement. The secondary objective was to check the influence of residents’ previous experience in spine surgery.

The main hypothesis was that theoretical learning with practical application on synthetic bone was superior to theoretical learning alone.

Twenty-three orthopedic residents were taught about free-hand pedicle screw placement using a theoretical presentation. Six residents had previous experience with screwing techniques. After randomization in two groups, 11 residents (group 1) participated in a workshop on synthetic bone, whereas 12 residents received only theoretical instruction (group 2). Each resident was asked to place two thoracic screws (T7-T11) and two lumbar screws (L1-L5) on a cadaver. Screw placement accuracy was analyzed using the Gertzbein classification on computed tomography (grades 0 and 1=accurate positioning; grades 2 and 3=malposition>2mm).

Rates of accurate screw positioning were 64.0% and 62.5% for thoracic levels, and 72.7% and 66.6% for lumbar levels in group 1 and 2, respectively. There was no significant difference in malposition rates on cadavers between the groups (p=0.1809). A resident who was first trained by simulation had a chance of decreasing the Gertzbein score with an odds-ratio of 1.7714 [0.7710–4.1515]. The odds ratio was 4.5188 [0.0456–0.8451] when comparing residents with previous experience in spinal surgery to novice residents.

Theoretical teaching associated with a simulation model is relevant for learning a surgical technique. A single simulation workshop on synthetic bone seems insufficient to improve pedicle screw placement accuracy compared to theoretical teaching alone. Progressive experience and the repetition of technical gestures during hands-on supervised learning in spine surgery with a senior surgeon had an influence on the accuracy of pedicle screw placement.

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