Percutaneous iliosacral screw insertion: malpositioning and revision rate of screws with regards to application technique (navigated vs. Conventional).
BACKGROUND
Conventional percutaneous iliosacral screw placement in pelvic surgery is considered to be a highly demanding operative technique with a high rate of screw malpositions, which may be associated with the risk of neurologic damage or inefficient stability. In the conventional technique, the correct entry point for the screw and the small target corridor for the iliosacral screw may be difficult to visualize using an image intensifier. We tried to find out in this study whether the positioning of percutaneous screw implantations could be optimized by evaluating the rate and grade of malpositions and whether the needed revisions could be reduced by using computer navigation and three-dimensional (3D) image intensifier.


METHODS
A group of 54 patients with 63 screws implanted using computer navigation was compared with 87 patients with 131 screws implanted using the conventional fluoroscopic technique. The exact screw position was controlled in a postoperative computed tomography scan, and the grade of malposition of every screw was investigated and compared.


RESULTS
A complete intraosseous screw position was found in 42% of cases using the conventional technique and was significantly less compared with 81% using a 3D image intensifier in combination with a navigation system. Moreover, the revision rate of 1.6% was significantly less in the navigated group compared with 19% in the conventional group.


CONCLUSIONS
The results indicate that 3D-computer navigation of the percutaneous iliosacral screw insertion can facilitate surgical performance in respect to reducing screw malposition and revision rates.
Department of Orthopaedic and Trauma Surgery, University of Freiburg Medical Center, Freiburg, Germany. jzwingmann@freenet.de
J
J
Zwingmann
G
G
Konrad
A T
AT
Mehlhorn
N P
NP
Südkamp
M
M
Oberst
D000328:Adult; D001863:Bone Screws; D001864:Bone Wires; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D021621:Imaging, Three-Dimensional; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging* / Q000293:injuries / Q000601:surgery*; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome