Minimally invasive fixation of sacroiliac triangle for vertically unstable pelvic posterior ring injury

Abstract

Objective To investigate the clinical results of minimally invasive fixation of the sacroiliac triangle for vertically unstable pelvic posterior ring injury. Methods A retrospective study was conducted of 20 patients who had been treated for vertically unstable pelvic posterior ring from January 2014 to August 2016. They were 12 males and 8 females, aged from 20 to 58 years (average, 35 years). According to Tile classification for pelvic fractures, there were 4 cases of type C1.1, 6 cases of type C1.2, 7 cases of type C1.3 and 3 cases of type C2. Their posterior rings were treated by fixation through posterior paraspinal approach with S1-iliac pedicle screws plus percutaneous sacroiliac screws, and their anterior rings by closed reduction and internal fixation with cannulated screws, Infix or plate following open reduction. The incision length, operation time and intraoperative blood loss were recorded. Postoperative reduction quality was assessed by Matta radio-logical criteria and pelvic function by Majeed criteria at the final follow-ups. Results Altogether 20 fixation systems of S1-iliac pedicle screws and 37 sacroiliac joint screws were inserted in this series. The length of incision ranged from 5.5 to 7.6 cm (average, 6.2 cm), the operation time from 89 to 130 minutes (average, 98 minutes) and the intraoperative blood loss from 110 to 320 mL (average, 195 mL). According to Matta ra-diological criteria, reduction was excellent in 13, good in 5 and fair in 2 cases, with an excellent and good rate of 90%. The follow-up time for the 20 patients ranged from 6 to 15 months (average, 9 months). The healing time ranged from 10 to 14 weeks(average, 12.5 weeks). At the final follow-ups, X-ray and CT three-dimensional reconstruction showed fine fracture union. By the Majeed criteria, the pelvic function was excellent in 11 cases, good in 5, fair in 3, and poor in one, with an excellent and good rate of 80%. No loosening, breakage or pull-out of pedicle screws or sacroiliac screws happened. Conclusion Minimally invasive fixation of the sacroiliac triangle for vertically unstable pelvic posterior ring injury can lead to precise placement, quick recovery, small incision and good functional outcome. Key words: Pelvis; Fractures, bone; Fracture fixation, internal; Surgery, minimally invasive