gms | German Medical Science

Objectives: To investigate the clinical significance of excessive inlet view in fluoroscopy assisted placement of sacroiliac screws.

Methods: Included for this prospective study were 47 patients with unstable pelvic fractures who had been admitted to Department of Orthopaedic Trauma, Xi'an Honghui Hospital between January 2020 and January 2021.There were 30 males and 17 females, with a mean age of 39.4 years (from 25 to 66 years). By the Tile classification, 21 fractures were type B and 26 fractures were type C. The inlet view and the angle of excessive inlet view were measured before operation. The intraoperative placement of sacroiliac screws was assisted by C-arm fluoroscopy navigation. The positions of sacroiliac screws were verified by CT or O-arm fluoroscopy after operation. The screw placement time, fracture reduction quality, fracture healing time, and pelvic function at the last follow-up were recorded.

Results: A total of 67 screws were implanted in the 47 patients, including 56 sacroiliac screws. The average time for insertion each screw was 19.9 mins (from 9 to 31 mins). The average angle of excessive inlet view was 17.38° (from 12.1° to 24.8°). All sacroiliac screws were located in the sacral canal without breaking through the cortical bone. By the postoperative Matta scoring, the reduction was excellent in 22 cases, good in 17 cases. acceptable in 6 cases. and poor in 2 cases. The rating of excellent and good was 83.0% (39/47).The average follow-up time was 9.5 months(from 5 to 15 months). The healing time averaged 10.5 weeks (from 7 to 16 weeks). At final follow-up,by the Mejeed score, the function was excellent in 26 cases, good in 15 casesand acceptable in 6 cases,the excellent and good rating was 87.2%(41/47).

Conclusion: Flouoroscopy in the excessive inlet view is a simple and easy intraoperative technique. It can improve accuracy and safety of sacroiliac screw placement. Because it allows clear identifcation of the posterior border of the sacrum and effectively avoids iatrogenic injury to the sacral nerve caused by screws breaking through the bone cortex.