What is the treatment for a patella fracture?

Treatment of Patella Fractures

The treatment of patella fractures should be determined based on fracture type, displacement, and integrity of the extensor mechanism, with surgical fixation recommended for fractures with displacement >2-3mm, articular step-off >2-3mm, or disruption of the extensor mechanism. 1

Assessment and Classification

• Evaluate for obvious deformity, swelling, bruising, severe pain with movement, or inability to move the affected knee 2, 3
• Radiographic assessment should include anteroposterior and lateral views of the knee 1
• CT imaging may be beneficial for complex fractures to better understand fracture complexity and guide treatment decisions 1
• Assessment of extensor mechanism integrity is crucial as it determines treatment approach 4

Treatment Algorithm

Non-operative Management

• Indicated for undisplaced fractures with an intact extensor mechanism 1
• Conservative treatment typically involves:
  • Immobilization with rigid splinting or casting 2, 5
  • Pain management and activity modification 3
• Risk of subsequent displacement (30-50%) should be considered when choosing non-operative management 6

Surgical Management

• Indications for surgical intervention include:

  • Fractures with >2-3mm of displacement 1
  • Articular step-off >2-3mm 1
  • Disruption of the extensor mechanism 1, 4
  • Open fractures 2, 3

• Surgical options include:

  • Modified anterior tension band wiring - treatment of choice for non-comminuted transverse (2-part) fractures 7
  • Cannulated screw fixation - can be combined with tension band wiring for biomechanical superiority 7
  • Small fragment screws or angular stable plates - for comminuted fractures requiring anatomic restoration of the retropatellar surface 7
  • Circular cerclage wiring (metal, resorbable PDS, or non-resorbable FiberWire) - to increase fixation stability 7
  • Partial or complete patellectomy - rarely used salvage procedure due to severe functional impairment 7

Complications and Their Management

• Common complications following patella fracture treatment include:

  • Nonunion, infection, posttraumatic arthritis, arthrofibrosis, symptomatic hardware, and extensor mechanism insufficiency 8
  • Patellofemoral osteoarthritis is very common after healing of patella fractures 4
  • Hardware-related pain often necessitates removal after fracture healing 1

• Risk factors for complications:

  • Patient factors (age, bone quality, activity level, compliance) 7
  • Injury factors (fracture pattern, associated soft tissue damage) 7
  • Treatment factors (inadequate reduction, fixation failure) 8

Rehabilitation

• Early rehabilitation is recommended to avoid knee joint capsule contractures and cartilage degeneration 7
• Rehabilitation should include:
  • Early motion exercises to prevent stiffness 2
  • Muscle strengthening exercises 2, 5, 3
  • Long-term continuation of knee exercises 2, 5, 3
  • Patient education about pain management strategies 5, 3

Special Considerations

• For patellar fractures after total knee arthroplasty:

  • Minimally displaced, non-comminuted fractures can be treated with immobilization 9
  • Displaced, comminuted fractures with loose patellar prostheses require operative treatment 9
  • The incidence of patellar fractures is significantly higher after patella resurfacing and revision arthroplasty 9

• For severe trauma patients:

  • In patients with multiple injuries, timing of definitive fixation should consider overall patient status 6
  • Temporary stabilization may be necessary in patients with circulatory shock, respiratory failure, or severe visceral injuries 6