Weightbearing Progression After Percutaneous Fixation of Sacral Fracture with Pubic Rami Fractures
Following percutaneous fixation of a sacral fracture with superior and inferior pubic rami fractures, early functional rehabilitation with progressive weightbearing should be initiated, with the specific progression dependent on the stability of the fixation construct and anterior fracture pattern. 1
Immediate Postoperative Weightbearing Strategy
The fundamental goal of internal fixation for unstable pelvic ring injuries is to allow early functional rehabilitation and decrease long-term morbidity, chronic pain, and complications historically associated with prolonged immobilization. 1
For Stable Fixation Constructs
Patients with spinopelvic (triangular) fixation can begin immediate full weightbearing at 6 weeks postoperatively, as this construct provides superior biomechanical stability that prevents reduction loss in vertical shear sacral fractures. 2
Triangular osteosynthesis (lumbopelvic fixation combined with iliosacral screw fixation) demonstrates significantly smaller displacement under peak loads (0.163 ± 0.073 cm) compared to standard iliosacral screw fixation alone (0.611 ± 0.453 cm), providing the mechanical advantage needed for early weightbearing. 3
For Standard Percutaneous Iliosacral Screw Fixation
If only posterior percutaneous fixation was performed, the anterior fracture pattern is the critical determinant of weightbearing progression. 4
Patients with comminuted or oblique ipsilateral superior AND inferior pubic rami fractures have 95.6-100% risk of subsequent displacement with posterior-only fixation, making them poor candidates for early weightbearing without supplemental anterior fixation. 4
Patients with transverse or absent inferior pubic ramus fractures (0% displacement risk) can safely progress to weightbearing more rapidly. 4
Recommended Weightbearing Protocol
Week 0-6 Postoperatively
Touch-down weightbearing (TDWB) to partial weightbearing (PWB) at 20-30% body weight for patients with standard iliosacral screw fixation and stable anterior fracture patterns (transverse rami fractures). 1
Non-weightbearing (NWB) to TDWB only for patients with comminuted/oblique superior and inferior pubic rami fractures treated with posterior-only fixation, due to high displacement risk. 4
Week 6-12 Postoperatively
Progress to weightbearing as tolerated (WBAT) for patients with spinopelvic fixation, as this construct allows full weightbearing by 6 weeks. 2
Progress to PWB at 50% body weight for standard iliosacral screw fixation with stable anterior patterns, advancing by 25% every 2 weeks based on pain tolerance and radiographic evidence of healing. 1
Week 12+ Postoperatively
- Advance to full weightbearing once radiographic evidence of bone union is demonstrated at the superior pubic ramus and sacral fracture sites. 5
Critical Pitfalls to Avoid
The most common error is applying posterior-only fixation to patients with comminuted or oblique ipsilateral superior and inferior pubic rami fractures and then allowing early weightbearing. All 11 patients (100%) with this combination experienced displacement at follow-up in one study. 4
Nakatani zone I and II rami fractures correlate most strongly with subsequent displacement risk and require either supplemental anterior fixation or protected weightbearing. 4
Examination under anesthesia should be strongly considered for patients with comminuted/oblique rami fractures to disclose occult instability, regardless of whether the sacral fracture is complete or incomplete. 4
Monitoring During Progression
Serial radiographs at 2,6, and 12 weeks postoperatively to assess for loss of reduction or hardware failure before advancing weightbearing status.
Pain-guided progression: Patients should not advance weightbearing if experiencing significant pain at the fracture site, as this may indicate inadequate healing or construct failure.