What are intraarticular and extraarticular fractures of the wrist?

Intra-articular and Extra-articular Fractures of the Wrist

Intra-articular fractures involve the joint surface of the wrist, while extra-articular fractures occur outside the joint space, with the former typically requiring more aggressive management due to their impact on long-term joint function and risk of post-traumatic arthritis. 1, 2

Classification and Definitions

• Extra-articular fractures: Fractures that occur outside the radiocarpal joint space, not involving the articular surface of the distal radius 1
• Intra-articular fractures: Fractures that extend into the radiocarpal joint surface, disrupting the articular cartilage 2
  • Common types include:
    • Die-punch fractures (depression of the lunate facet) 1, 2
    • Volar rim fractures 2
    • Dorsally displaced intra-articular fractures 2

Clinical Significance

• Intra-articular fractures with ≥1 mm of displacement have significantly higher risk of post-traumatic arthritis (91% vs 11% in congruent joints) 3
• Restoration of articular congruity to within 1 mm is critical to minimize risk of long-term osteoarthritis 2
• Extra-articular parameters (especially radial length) are important for recovery of motion and preventing distal radioulnar joint problems 2

Imaging Evaluation

Initial Assessment

• Standard 3-view radiographic examination is the first-line imaging for suspected wrist fractures 1
  • Posteroanterior (PA), lateral, and 45° semipronated oblique views 1
  • A fourth semisupinated oblique view may increase diagnostic yield 1

Advanced Imaging for Equivocal Cases

• CT without IV contrast is recommended when radiographs are equivocal 1

  • Superior for detecting intra-articular extension of distal radius fractures 1
  • Three-dimensional reconstructions are helpful for preoperative planning of complex articular injuries 1
  • Cannot evaluate concomitant ligamentous injuries 1

• MRI without IV contrast can detect occult fractures when radiographs are normal but clinical suspicion remains high 1

  • Shows both intra-articular extension and concomitant ligament injuries 1
  • Particularly useful for evaluating scapholunate ligament tears that may affect surgical treatment 1

Management Considerations

Extra-articular Fractures

• Often managed non-operatively with cast immobilization 1
• Surgical fixation may be indicated if there is significant displacement or angulation 1

Intra-articular Fractures

• Surgical treatment is typically indicated for intra-articular fractures with ≥1 mm of displacement 2

• Surgical options include:

  • Limited open reduction and internal fixation 2
  • Arthroscopically assisted internal fixation 4
  • Open reduction and internal fixation (often with volar locking plates) 5

• The surgical approach is determined by the fracture pattern:

  • Volar approach for displaced volar rim fractures 2
  • Dorsal approach for dorsally displaced fractures or impacted die-punch fractures 2

Arthroscopic Evaluation

• Arthroscopy is an option during surgical treatment of intra-articular fractures to:
  • Improve diagnostic accuracy for wrist ligament injuries 1
  • Assist with reduction of articular fragments 4
  • Allow visual inspection and lavage of the joint 4

Prognostic Factors

• Severity of initial displacement 2
• Amount of comminution 2
• Number of fracture fragments 2
• Accuracy of articular surface reconstruction (goal: <1 mm step-off) 2, 3
• Simple intra-articular fractures in the sagittal plane may have outcomes comparable to extra-articular fractures when properly reduced and fixed 6

Common Complications

• Post-traumatic arthritis (65% of intra-articular fractures in young adults) 3
• Tendon ruptures (particularly extensor pollicis longus) 5
• Median nerve complications 5
• Compartment syndrome 5
• Wound infections 5