Distal Phalanx Anatomy

 

  • The distal phalanges are very small terminal bones of the fingers and plays a crucial role in fine motor skills.
  • The base of the distal phalanx, which is part of the DIP joint is covered with articular cartilage.
  • The middle phalanx has three basic parts: The distal tuft the shaft or diaphysis, and the base.
  • The concave proximal ends of the distal phalanx articulate with the middle phalanx.
  • The proximal end of the 2nd, 3rd, 4th, and 5th distal phalanges articulate with the head of the 2nd, 3rd, 4th, and 5th middle phalanges.
  • Dorsally the terminal extensor tendon inserts into a dorsal tubercle at the base of the distal phalanx.
  • Palmarly the FDP tendon inserts into the palmar aspect of the base of the distal phalanx.
  • The FDP inserts slightly volar and distal to the attachment of the volar plate to the base of the distal phalanx.
Diagrams & Photos
  • Distal phalanx
    Distal phalanx 16, 17, 18 & 19
  • Normal X-ray Image of distal phalanx, middle phalanx, proximal phalanx, and metacarpals.
    Normal X-ray Image of distal phalanx, middle phalanx, proximal phalanx, and metacarpals.
  • Anatomic Image of distal phalanx, middle phalanx, proximal phalanx, and metacarpals.
Key Points
  • Numerous fascial bands attached in the skin of the pulp to the distal phalanx.
  • An abscess (a felon) can develop in the fascial compartments of the pulp.
  • The fingernail is firmly attached to the dorsum of the distal phalanx. 
  • The Landsmeer ligaments, specifically the Oblique Retinacular Ligament (ORL) attach to the dorsal proximal distal phalanx.  This ligament helps synchronize PIP and DIP joint motion.
  • In the growing child there is an epiphyseal plate in the base of the middle phalanx.
  • The distal phalanges are fractured frequently.
  • Distal phalanx fractures are often open fractures.
Anatomy References
Anatomic Abbreviations
Hand Surgery Resource Anatomy Diagnostic Guide (Chapter)