What is the treatment for a patellar spur fracture?

Treatment of Patellar Spur Fracture

The treatment of patellar spur fractures should be based on displacement and extensor mechanism integrity, with non-displaced fractures managed conservatively and displaced fractures requiring surgical fixation. 1

Diagnostic Evaluation

• Initial assessment should include standard radiographs (anteroposterior and lateral views) to confirm the fracture pattern and degree of displacement 2
• CT imaging may be necessary for better understanding of fracture complexity when radiographs are inconclusive 3

Treatment Algorithm

Conservative Management

• Indicated for:
  • Non-displaced fractures (< 2-3 mm step-off and < 1-4 mm displacement)
  • Intact extensor mechanism 1, 3
• Protocol includes:
  • Immobilization in extension using a knee brace or cast
  • Protected weight-bearing for 4-6 weeks
  • Progressive range of motion exercises after initial immobilization period
  • Pain management with NSAIDs (naproxen 500mg twice daily or ibuprofen 1.2-2.4g daily) 4

Surgical Management

• Indicated for:
  • Fractures with > 2-3 mm step-off
  • Fractures with > 1-4 mm displacement
  • Disruption of the extensor mechanism 1, 3
• Surgical options:
  • Tension band wiring (most common technique)
  • Partial patellectomy (for comminuted fractures not amenable to reconstruction)
  • Total patellectomy (rarely, for severely comminuted fractures) 5

Rehabilitation Protocol

• Phase 1 (0-4 weeks): Pain control and protected range of motion 4

  • Quadriceps strengthening exercises
  • Progressive weight-bearing as tolerated

• Phase 2 (4-8 weeks): Progressive strengthening 4

  • Eccentric strengthening exercises
  • Functional bracing if needed

• Phase 3 (8-12 weeks): Return to function 4

  • Occupation-specific training
  • Functional exercises

Complications and Management

• Hardware-related pain is common after surgical fixation and may require removal after fracture healing 3
• Other potential complications include:
  • Nonunion
  • Infection
  • Posttraumatic arthritis
  • Arthrofibrosis
  • Extensor mechanism insufficiency 6

Special Considerations

• Periprosthetic patellar fractures (after total knee arthroplasty) require special attention:
  • Type I non-displaced fractures can be treated non-operatively
  • Displaced fractures may require resection arthroplasty with open reduction and internal fixation 5
  • Partial or total patellectomy may be necessary in severely comminuted cases 5

Follow-up

• Regular assessment at 2,6, and 12 weeks to evaluate:
  • Pain levels
  • Range of motion
  • Functional improvement
  • Signs of complications 4
• Return to full activity permitted when:
  • Complete resolution of pain
  • Full range of motion
  • Strength symmetry >90% compared to uninjured side 4

Pitfalls to Avoid

• Inadequate reduction of articular surface can lead to posttraumatic arthritis 3
• Overtightening of tension band constructs may lead to fracture comminution
• Delayed mobilization can result in knee stiffness and arthrofibrosis
• Failure to address concomitant injuries may lead to poor outcomes