Validity of a Novel Free-Hand Pedicle Screw Placement Training Tool

This study establishes the construct validity of a low-cost training platform designed for high-repetition training of the skills required for fluent use of the five specific tools described for free-hand pedicle screw placement and breach avoidance.

A total of 19 participants were included and divided into three groups based on spine surgery experience. Participants were asked to place five pedicle screws into the model. The performance was assessed by recording breaches, technical criteria (0 to 44 points), time to completion, and angulation of the screws. Success (no breaches, no protrusions) frequency (success/time) was calculated and analyzed.

Participants included three spine surgeons, seven advanced trainees (who had placed >10 pedicle screws), and nine inexperienced trainees. None of the screws placed by the spine surgeons breached the pedicle wall. Eight of 35 screws placed by advanced trainees (22.9%) and 31 of 45 screws placed by inexperienced trainees (68.9%) had a pedicle breach. Spine surgeons had a higher median success frequency compared with inexperienced trainees and advanced trainees (P = 0.015). The time needed to place a screw decreased over time (P < 0.0001). There was a trend toward an association between increased training level and decreased time to place five screws (P = 0.076). Increased training level was associated with greater total points scored (P < 0.0001). More screws placed by inexperienced trainees were further away from the ideal pedicle axis compared with those placed by advanced trainees or spine surgeons.

An association exists between training level and performance on the pedicle screw model, which suggests construct validity when evaluating our model's use for teaching surgeon learners. The model is easily assembled and is an alternative spine surgery training tool that overcomes limited availability and considerable costs of other training platforms. It can be used in high repetition to establish tool-skill fluency.

Level I.