The goal of this clinical trial is to learn about the surgical techniques of percutaneous sacroiliac screw fixation both the two-view fluoroscopic technique (sacral inlet and outlet views) and the standard three-view fluoroscopic technique (lateral, sacral inlet, and sacral outlet views).

The main questions it aims to answer is:

• Is there any difference of the operative time, intraoperative radiation exposure time, screw malposition rate, and postoperative neurological complication rate for percutaneous pelvic screw fixation between two techniques?

Researchers will compare two surgical techniques of percutaneous sacroiliac screw fixation in high energy posterior pelvic ring injured patients.

Participants will:

• Be examined neurological status carefully before and after the operation
• Get both preoperative and postoperative CT scan
• Undergo the percutaneous sacroiliac screw(s) fixation with or without anterior plating fixation

Inclusion Criteria:

1. Patients with traumatic posterior pelvic ring or sacral fractures indicated percutaneous screw fixation.
2. Patients who are fully conscious, possess decision-making capacity, and can provide informed consent.

Exclusion Criteria:

1. Presence of severe sacral dysmorphism (sacral dysmorphic score > 70 and absence of osseous corridor)
2. Concomitant diagnosis of osteoporosis or age more than 60 years
3. Age under 20 years or evidence of skeletal immaturity
4. Pregnancy
5. Highly comminuted sacral fractures precluding accurate intraoperative assessment of the screw trajectory
6. Pre-existing lumbosacral neurological deficits prior to surgery

Withdrawal Criteria:

1. Intraoperative necessity to convert to an alternative surgical method (e.g., inability to safely proceed with percutaneous fixation).
2. Absence of postoperative computed tomography (CT) scan
3. Loss to follow-up within 2 months postoperatively