[Application effect of probing technique on reducing screw cut-out risk during sacroiliac screw placement]

To evaluate the application effect of the probing technique in reducing the risk of screw cutout during sacroiliac (SI) screw placement and to provide a reference for improving the accuracy and safety of screw insertion.

A retrospective analysis was conducted on the clinical data of 46 patients with pelvic fractures who underwent percutaneous SI screw placement from October 2019 to December 2024. Patients were divided into a traditional group (n=24) and a probe group (n=22). The traditional group included 14 males and 10 females, aged 19 to 66 years with a mean of (41.88±14.07) years. The probe group included 12 males and 10 females, aged 21 to 64 years with a mean of (39.91±12.86) years. All patients presented with posterior pelvic ring instability, and fracture types were confirmed by preoperative imaging according to the OTA/AO classification. The traditional group received conventional fluoroscopy-guided screw placement, while the probe group adopted a "guidewire-cannulated screw-probe" stepwise insertion technique. Outcome measures included operation time, number of fluoroscopic exposures, screw placement accuracy (assessed by postoperative thin-slice CT using the modified Gras classification), and complications.

Across the two groups, 57 sacroiliac screws were placed (30 in the traditional group and 27 in the probe group). All patients completed the follow-up, with a duration ranging from 6 to 24 months with a mean of (16.5±4.8) months. Incision healing was successful in all patients postoperatively. The mean number of fluoroscopic exposures in the probe group (17.8±3.9) times was significantly lower than that in the traditional group (23.6±5.1) times (P< 0.001). The mean operation time in the probe group(19.9±5.8) min was significantly shorter than that in the traditional group (23.8±6.3) min (P=0.021). According to the modified Gras grading, the rate of screw malposition in the probe group was 3.7% (1/27), which was lower than 16.67% (5/30) in the traditional group. No revision surgeries were required in the probe group, whereas one case in the traditional group required revision.

The probing technique, utilizing tactile feedback within the osseous canal, reduces intraoperative fluoroscopy frequency and operation time while lowering the risk of screw malposition. This technique demonstrates good applicability in patients with sacral anatomical variations or narrow osseous channels, providing a safe and efficient method for the precise placement of SI screws.