Volar Plate Fracture

• Volar plate forms floor of PIP joint and separates the joint space from the flexor tendons
  • Volar plate is ligamentous at its origin on the proximal phalanx
  • Cartilaginous in its insertion onto the middle phalanx
• Hyperextension injury
• Involves PIP joint of fingers
• Primarily a ligamentous injury that can result in fracture
• Injury to the PIP joint is relatively common in athletics, especially sports involving ball-handling
  • “Jammed finger”
• If force of injury is great enough, dorsal dislocation can occur
  • Rupture of volar plate may occur with longitudinal splitting of the collateral ligament structures
    • Allows for complete dorsal displacement of middle phalanx
    • Simple dislocations easily reduced by player coach, or trainer on the field
    • Following reduction, most dorsal dislocations are stable
• Fractures of base of middle phalanx also occur in association with dorsal dislocations
  • If fracture involves more than 40-50% of articular surface
    • Collateral ligament support is lost
    • Combined with coexistent volar plate disruption
      • Represents major loss of joint stability
      • These injuries are often unstable, exhibiting persistent subluxation of the middle phalanx
        
        
• Imaging findings
  
  
  • Small fragment of bone is avulsed from palmar (volar) aspect of base of middle phalanx

• Complications
  
  
  • Joint instability
  • Associated collateral ligament tear may heal with abundant fibrous tissue producing bump on one side of joint

Volar Plate Fracture. There is a small avulsed fragment of the base of the middle phalanx of the middle finger from a volar plate injury

Michael E. Robinson, MD  eMedicine.com