What is the recommended management for a non‑union comminuted fracture of both the inferior and superior pubic rami?

Management of Non-Union Comminuted Pubic Rami Fractures

For a non-union comminuted fracture of both the inferior and superior pubic rami, surgical fixation is indicated, particularly when displacement exceeds 15-16 mm or when the patient has persistent pain and functional impairment limiting ambulation.

Assessment of Stability and Surgical Indication

The critical first step is determining whether this represents an isolated anterior ring injury or part of a complete pelvic ring disruption with posterior instability. This fundamentally changes management:

• Check for posterior pelvic ring involvement (sacral fractures, sacroiliac joint disruption, iliac wing fractures) on CT imaging
• Measure initial fracture displacement - displacement ≥16 mm is a significant risk factor for non-union and predicts failure of conservative management 1
• Assess mechanical stability using the Young & Burgess classification system

When Surgical Fixation is Required

Posterior pelvic ring instability represents an absolute surgical indication for anatomic fracture reduction and stable internal fixation 2. The goal is achieving anatomic reduction and stable fixation to allow early functional rehabilitation and decrease long-term morbidity, chronic pain, and complications from prolonged immobilization 2.

For isolated anterior ring non-unions with persistent symptoms, surgical intervention provides more rapid symptom relief and faster functional recovery 3.

Surgical Approach and Technique

For Symptomatic Non-Union of Pubic Rami:

The superior pubic ramus should be addressed as the primary target, as this often leads to indirect healing of inferior ramus fractures:

• Open reduction internal fixation (ORIF) with bone grafting through a modified Stoppa approach is the preferred method for most cases 4

  • Allows excellent exposure while minimizing soft tissue trauma
  • Facilitates direct visualization of the non-union site
  • Enables placement of autologous iliac bone graft (gold standard for pelvic non-unions) 5
  • Use of reconstruction plating for anterior fixation

• Alternative: Percutaneous retrograde superior ramus screw fixation for hypertrophic non-unions with suitable anatomy 6, 7

  • 5.5 mm cannulated retrograde superior ramus screws demonstrate superior biomechanical performance compared to 3.5 mm reconstruction plates 8
  • Requires excellent preoperative planning and understanding of pelvic fluoroscopy
  • Avoids morbidity of extensive open procedures
  • Best suited for hypertrophic (not atrophic) non-unions

If Posterior Ring Instability is Present:

Combined anterior and posterior fixation is mandatory 2:

• Posterior fixation options:

  • Minimally invasive percutaneous iliosacral screw fixation (S1 and S2 corridors)
  • Spinopelvic fixation for vertically unstable sacral fractures (allows immediate weight-bearing) 2
  • Tension band plating for posterior ring injuries

• Anterior fixation:

  • Pubic symphysis plating for diastasis >2.5 cm (Grade 1A recommendation) 2
  • Superior ramus plating or screw fixation as described above

Critical Technical Considerations

Bone Grafting Approach

When bone grafting is required for atrophic non-union:

• Posterior approach allows direct visualization of the non-union site and precludes nerve root injury 5
• Autologous iliac crest bone graft remains the gold standard
• Combine with stable internal fixation (CT-guided percutaneous iliosacral screws posteriorly if needed, plus anterior fixation) 5

Common Pitfalls to Avoid

1. Underestimating posterior ring involvement - Always obtain CT imaging to rule out occult posterior instability
2. Inadequate fixation of comminuted fractures - Comminution requires more robust fixation strategies; consider combined plating and bone grafting
3. Treating displacement <16 mm conservatively when symptomatic - While guidelines suggest non-operative management for stable patterns, persistent symptoms warrant intervention 1
4. Ignoring bilateral ramus fractures - These have higher non-union rates and may require bilateral fixation 1

Post-Operative Mobilization

• Early mobilization is the goal - typically ambulatory within 1 day post-fixation for isolated anterior ring repairs 3
• Weight-bearing status depends on:
  • Posterior ring stability (spinopelvic fixation allows immediate weight-bearing) 2
  • Quality of fixation achieved
  • Bone quality and comminution severity

Special Populations

Elderly patients and those with osteoporosis require particular attention:

• Higher risk of complications from prolonged immobilization
• May benefit from more aggressive surgical intervention even with seemingly stable fractures
• Consider augmentation techniques for poor bone quality

The evidence strongly supports that surgical intervention for symptomatic pubic rami non-unions provides superior functional outcomes compared to continued conservative management, with the specific technique guided by fracture characteristics, posterior ring stability, and patient anatomy 5, 4, 6, 3, 1.