Pubic Rami Fractures

Definition: Pubic rami fractures involve the superior and/or inferior pubic rami. They may be isolated (ring intact) or associated with posterior ring injury (sacral fracture, SI joint injury).

Epidemiology:

• Elderly Fragility Fractures: Most common presentation. Low-energy fall.
• Young High-Energy: MVA, Fall from height. Often part of major pelvic ring injury.
• Incidence: Very common fragility fracture. Often under-recognized.

Anatomy:

• Superior Pubic Ramus: Connects pubic body to acetabulum (forms anterior column).
• Inferior Pubic Ramus: Connects pubic body to ischium.
• Pubic Symphysis: Fibrocartilaginous joint at midline.

Ring Concept:

• The pelvic ring is a closed loop: Sacrum, SI joints, Innominate bones (Ilium, Ischium, Pubis), Symphysis.
• A complete ring cannot break in only one place. If rami are fractured, look posteriorly.

Exception:

• Insufficiency Fractures: Osteoporotic bone can have incomplete or subtle posterior fractures (Sacral insufficiency fractures).

History:

• Mechanism: Low-energy fall (elderly)? High-energy (young)?
• Pain Location: Groin, anterior pelvis.
• Mobility: Can they walk? Weight-bear?

Physical Examination:

• Tenderness: Pubic rami (groin/anterior pelvis).
• Deformity: Usually none (isolated stable fractures).
• Compression/Distraction: May elicit pain.
• Gait: Antalgic.
• GU Exam: Blood at meatus? Urethral injury in high-energy (especially males).
• PR/PV Exam: Assess for associated injury.

Imaging:

1. X-ray (AP Pelvis): Shows rami fractures. May miss posterior injury.
2. CT Pelvis: Essential. Assess posterior ring (Sacrum, SI joints).
3. MRI: If CT negative but high clinical suspicion. For occult sacral insufficiency fractures.

Key Findings:

• Rami Fractures: Usually visible on X-ray.
• Sacral Compression (LC-1): May be subtle on CT. Look for buckling of sacral ala.
• Sacral Insufficiency Fracture: Classic 'H-sign' (Honda sign) on bone scan / MRI (bilateral sacral ala + transverse fractures).

The elderly patient with groin or buttock pain and inability to weight-bear is not always a rami fracture. Distinguish:

Mortality:

• 1-year mortality for elderly pelvic fragility fractures is significant (10-20%).
• Similar to hip fractures.
• Orthogeriatric model of care improves outcomes.

Conservative Care:

• Mobilize Day 1.
• Walker/Frame.
• Physio daily.
• Discharge when safe (Home vs Rehab).

Post-Sacroplasty:

• Mobilize same day or next day.
• Weight-bear as tolerated.
• Follow-up X-ray.

• Isolated Rami: Good outcomes if mobilized early.
• With Ring/Sacral: May have chronic pain. Sacroplasty can help.
• Elderly Frailty: High morbidity/mortality from immobility.

Global epidemiology:

• Fragility fractures of the pelvis are rising rapidly with population ageing; the typical patient is a woman in her 80s after a low-energy fall.
• Women are affected roughly 5-6 times more often than men, reflecting postmenopausal bone loss.
• One-year mortality (around 15-20%) and loss of independence approach those of hip fracture, making this a sentinel frailty event rather than a benign injury.

Side-by-side guidance:

Registry and practice notes:

• No dedicated pelvic-fragility registry exists; data come from national hip-fracture registries and trauma databases, which increasingly capture pelvic fragility fractures under the same frailty pathways.
• Bone-health drugs (bisphosphonates, denosumab, and anabolic agents such as teriparatide/romosozumab) are standard secondary prevention after a fragility fracture; agent choice and access vary by region and fracture risk.

High- vs limited-resource variation:

• High-resource settings: routine CT, orthogeriatric co-management, fracture liaison services, and percutaneous fixation/sacroplasty for refractory pain.
• Limited-resource settings: diagnosis often rests on plain radiographs (risking missed posterior injury), with conservative analgesia and mobilization the mainstay and surgery reserved for clear instability.