What is the appropriate management of a left superior pubic ramus fracture in a patient with a prior left total hip arthroplasty?

Management of Superior Pubic Ramus Fracture with Ipsilateral Total Hip Arthroplasty

In a patient with a left superior pubic ramus fracture and prior left total hip arthroplasty, obtain a CT scan of the pelvis immediately before any mobilization to exclude acetabular component involvement or extension, as early mobilization without imaging can lead to catastrophic acetabular component displacement. 1

Critical Initial Assessment

Mandatory Imaging Protocol

• Standard radiographs are insufficient in patients with pubic ramus fractures and ipsilateral hip arthroplasty 1
• CT scan of the pelvis is mandatory to exclude:
  • Acetabular fracture extension 1
  • Periprosthetic acetabular fracture 2
  • Posterior column involvement 2
  • Acetabular component stability 1

High-Risk Scenario Recognition

• A case report documented a patient with "minimally displaced inferior pubic ramus fracture" and ipsilateral THR who was mobilized early with analgesia, but continued groin pain led to repeat radiographs showing acetabular fracture with displacement of the acetabular component 1
• Periprosthetic T-type acetabular fractures can present initially as isolated pubic ramus fractures, involving anterior and posterior columns with ischiopubic segment disruption 2

Treatment Algorithm Based on CT Findings

If Isolated Superior Pubic Ramus Fracture (No Acetabular Extension)

Conservative management is appropriate for truly isolated fractures:

• Hospital admission with interdisciplinary care program 3
• Multimodal analgesia incorporating nerve block (femoral or fascia iliaca) 3
• Early mobilization with weight-bearing as tolerated once acetabular involvement is definitively excluded 1
• Avoid NSAIDs if renal dysfunction present (common in 40% of hip fracture patients) 3

Surgical fixation may be considered if:

• Persistent pain despite adequate analgesia 1
• Inability to mobilize due to pain 4
• Concern for fracture displacement affecting hip prosthesis stability 1

If Periprosthetic Acetabular Fracture Identified

Surgical intervention is required:

• Retrograde percutaneous inferior pubic ramus screw fixation using fully-threaded 6.5-mm cannulated screws is effective for stabilizing the ischiopubic segment 2
• Combined with posterior column fixation if posterior column involvement present 2
• This approach prevents further displacement, facilitates early weight-bearing, and avoids revision arthroplasty 2

Surgical Technique Considerations (If Fixation Indicated)

Screw Placement Strategy

• Zone III fractures (lateral to obturator foramen) have no loss of reduction reported 4
• Retrograde screw placement has higher failure rates (11 of 12 failures in one series) 4
• Antegrade approach preferred when technically feasible 4
• Fully threaded screws may provide better purchase than partially threaded screws 4, 5

High-Risk Factors for Fixation Failure

• Female sex (10 of 12 failures) 4
• Elderly patients (average age 55 years in failure group) 4
• Fractures medial to lateral border of obturator foramen (Zones I-II) 4
• Most common failure mechanism: collapse of pubic ramus over screw with recurrent internal rotation deformity 4

Perioperative Management

Anesthesia and Analgesia

• Either spinal or general anesthesia appropriate 3
• Multimodal analgesia with preoperative nerve block strongly recommended 3
• Tranexamic acid administration to reduce blood loss 3

Orthogeriatric Comanagement

• Interdisciplinary care programs decrease complications and improve outcomes 3
• Assessment of cognitive function, nutritional status, renal function, and pressure sore risk 6
• Early mobilization essential to prevent pneumonia, DVT, and pressure ulcers 6

VTE Prophylaxis

• Pharmacologic VTE prophylaxis mandatory 6, 7
• Duration typically 1 month 3

Secondary Fracture Prevention

• Systematic osteoporosis evaluation for all patients ≥50 years with fragility fractures 6
• Fracture Liaison Service referral for risk evaluation and treatment initiation 6
• DEXA scan, vitamin D, calcium, and PTH levels 7

Common Pitfalls to Avoid

• Mobilizing before CT scan obtained - can cause acetabular component displacement 1
• Assuming all pubic ramus fractures are stable in patients with hip arthroplasty 1
• Relying solely on plain radiographs - inadequate to exclude acetabular extension 1
• Retrograde screw placement - associated with 15% loss of reduction rate 4
• Inadequate pain control - may mask progressive fracture displacement 1
• Failing to provide orthogeriatric comanagement - leads to suboptimal outcomes 6