Navigationsgestützte Arthrodese des Iliosakralgelenks

[Percutaneous, 2D-fluoroscopic navigated iliosacral screw placement in the supine position: technique, possibilities, and limits]

OBJECTIVE

In pelvic surgery, computer-assisted procedures are currently used predominantly for percutaneous iliosacral screw placement. The aim of this study was to evaluate the possibilities and limits of a 2D-fluoroscopic navigated procedure used for this indication.

METHODS

A consecutive series of patients with non or slightly displaced injuries of the posterior pelvic ring were prospectively investigated. Cannulated cancellous screws of 7.3 mm were percutaneously implanted in the supine position. The navigated procedure was performed using an active optoelectronical system and a 2D C-arm. Target parameters were practicability, precision and intraoperative radiation exposure time compared to patients treated using a non-navigated technique.

RESULTS

In a 15 month period, 35 screws were implanted in 20 patients. The average procedure took 36.2+/-12.5 min (range 18-62 min), with a fluoroscopic time of 0.9+/-0.3 min (range 0.6-1.8 min) per screw. The displacement rate was 8% (n=3/35, CI 1.8-23.0). Compared to retrospectively selected patients treated using a non-navigated technique (n=13), a significant increase in procedure time (P=0.01), a significant decrease of radiation exposure time (P<0.001) and a decreased displacement rate (P>0.05) were observed in the navigated group.

CONCLUSION

The 2D-fluoroscopic navigated procedure used in this study can be recommended for percutaneous stabilisation of non or minor displaced injuries of the posterior pelvis. This procedure reduces intraoperative radiation exposure and improves intraoperative orientation but does not crucially enhance the precision of screw placement compared to the non-navigated technique. Finally, it is limited by its poor image resolution and lack of three-dimensionality.

Image guidance in pelvic and acetabular surgery--expectations, success and limitations

During the last decade navigation techniques in pelvic and acetabular surgery have been described. Nowadays, available techniques include CT-based navigation, 2D C-arm navigation and 3D C-arm navigation. The main indication is the navigated percutaneous SI screw fixation, but acetabular screw fixations are also reported. In this article, based upon a literature review and our own clinical experiences, the indications for and limitations of navigated techniques in pelvic and acetabular surgery are described.