Preoperative CT Simulation of Iliosacral Screws for Treating Unstable Posterior Pelvic Ring Injury

BackgroundPercutaneous iliosacral screw placement is an important surgical method for the treatment of pelvic unstable fractures, but either intraoperative X-ray screws or navigational screws may be misplaced. This study aimed to demonstrate a safe, effective, and rapid medthod for placing iliosacral screws for the treatment of unstable posterior pelvic ring injury according to preoperative computed tomography (CT) planning using simulated screws. MethodsAfter preoperative CT simulation of iliosacral screws planning screw insertion point and trajectory, intraoperative percutaneous iliosacral screws were used to treat unstable pelvic posterior ring injury.The mechanism of injury, Tile classification, number of screw implants, operative time of each screw implantation, radiation exposure time of each screw implantation screw position, complications, and postoperative follow-up time were collected.Screw position grading was evaluated by Smith grading. ResultsA total of 24 screws were implanted in 21 patients (9 men and 12 women;mean age 41.3 years:range 14-71 years). Tile classification included:Tile B:15 patients;Tile C:6 patients. The mean placement time of each screw was 19.5 minutes (range 14-32min); Radiation exposure time: 0.6 min (range 0.5-0.9min); Two screws were inserted in 3 patients; One screw was inserted in 18 patients; According to Smith grading standard, grade0:20 cases; and Grade1:1 case; Mean postoperative follow-up time was 17.1months (range12-25 months); None of the patients showed nonunion. ConclusionsPreoperative CT simulation of iliosacral screws for placement planning, screw trajectory, and intraoperative placement of screws is a safe method that can be used to reduce surgical time, radiation exposure, and accurate screw placement.

Pelvic antropometric measurement in 3D CT for placement of two unilateral iliosacral S1 - 7.3 mm screws

Purpose Stability of the dorsal pelvic ring is important for patient mobilisation and can be restored using several surgical procedures after fracture. Placement of percutaneous iliosacral screws is a reliable and minimal-invasive technique to achieve stabilisation of the dorsal pelvic ring by placement of two screws in the first sacral vertebra. Aim of this study was to evaluate 3D CT scans regarding the anatomical possibility to place two 7.3 mm iliosacral screws for fixation of the dorsal pelvic ring. Methods 3D CT datasets of 500 consecutive trauma patients with 1000 hemipelves of a mid-european level I trauma centre with or without pelvic injury were evaluated and measured bilaterally in this retrospective study. Results One thousand hemipelvic datasets of 500 patients (157 females, 343 males) with a mean age of 49.7 years (18 to 95) were included in this study. Only 16 hemipelves (1.6%, 11 in females, 5 in males) in 14 patients (2.8%, 9 females = 5.73%, 5 males = 1.5%) showed too narrow corridors so that 7.3 mm screw placement would not be possible (p = 0.001). In women, too narrow corridors occurred 3.9 times as often as in men. Only two females showed this bilaterally. Conclusion The evaluation of 3D CT scans of the pelvis showed the importance of planning iliosacral screw placement, especially if two 7.3 mm screws are intended to be placed in the first sacral vertebra.

Choosing between the Conventional Plates, Locking Plates, or Iliosacral Screws for Sacroiliac Joint Dislocation: A Biomechanical Comparison Study

Background: This study examines the comparison of biomechanical strengths of three kinds of the most familiar implants available in Indonesia: conventional and locking sacroiliac plates and screws, also iliosacral screws. Despite the common thought that iliosacral screws are preferred compared to conventional plates and screws due to its biomechanic superiority, this study tested whether the locking plates and screws could offer an alternative.Materials and Methods: This study was an in vitro experimental study with a Randomized Post Test - Only Control Group Design using pelvic bones from male cadavers aged 20-50 y.o. Twelve samples were divided into three treatment groups and one control group. Group P1 was fixed with two conventional plates, P2 was fixed with two locking plates, P3 was fixed with two iliosacral screws, and control group K with sacroiliac joint was intact. Each group was given an increasing load until a vertical shift of the sacroiliac joint ≥ 2.0 mm was obtained.Results: The average force load for 2 mm displacement among the fixation systems being tested shows a statistically significant difference (p0.05). Load failure force for 2 mm displacement in the locking plate and screw group has the highest average (591.33 ± 56.08 N) compared to the iliosacral screw group (583.67 ± 73.56 N) and conventional plate and screw group (574 ± 106.05 N).Conclusions: Biomechanically, the fixation system using two locking anterior sacroiliac plates and screws is more stable than the iliosacral screws and conventional sacroiliac plates and screws.

3D-Imaging navigation in posterior pelvic iliosacral screwing using the Surgivisio® system.

The recent studies about iliosacral screws performed with navigation systems show promising results. The Surgivisio system is a new generation of intraoperative 3D imaging technique used in our institution since two years. The aim of this prospective study was to evaluate the accuracy of iliosacral screw placement and radiation exposure with the Surgivisio® system.Between January 2018 and December 2019, every patient operated for percutaneous iliosacral screwing using the Surgivisio® system were included in this prospective single center study. Accuracy of screw placement was assessed with post-operative high- resolution CT-scan. Operative time, radiation exposure and complications were assessed.A total of 32 patients were included with 49 iliosacral screws. Using the modified Gras classification, 2% (1/49) were rated as misplaced and 2% (1/49) were repositioned. The mean operative time was 26 min for the whole procedure. The mean dose area product was 7.98 Gy.cm2. Two complications were recorded (neurological pain treated by removal of the misplaced screw, an asymptomatic cement leakage with one augmented iliosacral screw).The Surgivisio® system is an efficient navigation tool for iliosacral screwing in minimal invasive surgery. It improves the accuracy of screw placement with an acceptable radiation exposure and operative time.