Assessment of a percutaneous iliosacral screw insertion simulator

Navigational simulator use for specialized training purposes is rather uncommon in orthopaedic and trauma surgery. However, it reveals providing a valuable tool to train orthopaedic surgeons and help them to plan complex surgical procedures.

This work's objective was to assess educational efficiency of a path simulator under fluoroscopic guidance applied to sacroiliac joint percutaneous screw fixation.

We evaluated 23 surgeons' accuracy inserting a guide-wire in a human cadaver experiment, following a pre-established procedure. These medical trainees were defined in three prospective respects: novice or skilled; with or without theoretical knowledge; with or without surgical procedure familiarity. The screw insertion in the human cadaver was performed in two different settings: either without prior training for a first group (G1) or after simulator guidance in the second group (G2). Analysed criteria for each tested surgeon included the number of intraoperative X-rays taken in order to achieve the surgical procedure as well as an iatrogenic index reflecting the surgeon's ability to detect any hazardous trajectory at the time of performing said procedure.

An average number of 13 X-rays was required for wire implantation by the G1 group. G2 group, assisted by the simulator use, required an average of 10 X-rays. A substantial difference was especially observed within the novice sub-group (N), with an average of 12.75 X-rays for the G1 category and an average of 8.5 X-rays for the G2 category. In the second sub-group of operators devoid of procedural knowledge (P-), a significant difference was found, since 12 X-rays appeared on average required in the G1 group versus six in the G2 group. Finally, within the sub-group of operators with technical knowledge (T+), a significant difference also was found since an average of 16 X-rays was required in the G1 versus an average 10.8 X-rays in the G2 group. As far as the iatrogenic index is concerned, we were unable to observe any significant difference between the groups.

Despite some methodological variations, we were able to demonstrate the simulator's efficiency in familiarizing the operator with the use of a 2D imaging system as a first step facilitating the procedure conduct in the real 3D patient environment. Novice surgeons (N) having a good lumbosacral joint anatomy knowledge although devoid of specific surgical technique knowledge were the ones who most benefited from this guiding tool. Analysis of the training data collected during simulator's use helps orientating the prospective surgeon toward possession of not yet acquired learning points. This educational program can easily be extended to any other percutaneous technique requiring fluoroscopic control guidance.

Level III prospective diagnostic study.