Computer-assisted versus conventional surgery for insertion of 96 cannulated iliosacral screws in patients with postpartum pelvic pain

Background. The purpose of this study was to assess the value of fluoroscopy-based computer-assisted surgery (CAS) for the insertion of iliosacral screws. The results of CAS were compared with the results of a conventionally operated prospective control group. Endpoints of this study were fluoroscopy time, guide wire insertion time, operation time and complication rate. Methods: The study group consisted of 24 patients with postpartum pelvic pain syndrome. All patients were treated with a stabilization of the pelvic ring by means of an anterior plate fixation and autologous tricortical bone graft as well as two iliosacral screws bilaterally. Consequently, the results of 48 versus 48 iliosacral screw fixations could be evaluated. Conventionally operated patients were turned from the supine to the prone position intraoperatively, whereas CAS operated patients were operated in the supine position. One surgeon performed all operations. Results. The fluoroscopy time in the CAS group was 0.7 minutes versus 1.8 minutes in the conventionally treated group (p < 0.01). The mean insertion time for four guide wires was 20.2 minutes in the CAS versus 19.4 minutes in the conventionally operated group (p = 0.6). The mean operation time in the CAS group was 97 minutes; 116 minutes in the conventional group (p = 0.03). In the CAS group one patient had pain and a sensory deficit of S2 postoperatively. The Fisher's exact test showed no difference in complication rate between the two groups (p = 0.26). Conclusions: The fluoroscopy time is decreased with a factor 2.5 using CAS. Guide wire insertion time was similar in both groups. The reduction in operation time using CAS was due to fact that patients were operated in the supine position during the whole procedure. This study shows that CAS is a save technique for insertion of iliosacral screws.