Fingertip avulsion

Background

A. Nail plate; B. lunula; C. root; D. sinus; E. matrix; F. nail bed; G. hyponychium; H. free margin.

• Consult hand surgeon for all patients with Amputation proximal to the lunula (crescent-shaped whitish area)

Anatomy

• The perinychium includes the nail, the nailbed, and the surrounding tissue.
• The paronychia is the lateral nail folds
• The hyponychium is the palmar surface skin distal to the nail.
• The lunula is that white semi-moon shaped proximal portion of the nail.
• The sterile matrix is deep to the nail, adheres to it and is distal to the lunule.
• The germinal portion is proximal to the matrix and is responsible for nail growth.

Differential Diagnosis

Hand and finger injuries

• Distal finger
  • Finger amputation
  • Fingertip laceration
  • Nail avulsion
  • Nailbed laceration
  • Subungual hematoma
• Other finger/thumb
  • Boutonniere deformity
  • Mallet finger
    • Swan neck deformity
  • Jammed finger
  • Jersey finger
  • Trigger finger
  • Ring avulsion injury
  • De Quervain tenosynovitis
  • Infiltrative tenosynovitis
  • Metacarpophalangeal ulnar ligament rupture (Gamekeeper's thumb)
• Hand
  • Dupuytren contracture
• Wrist
  • Drummer's wrist
  • Ganglion cyst
  • Lunotriquetral ligament instability
  • Scaphoid fracture
  • Extensor digitorum tenosynovitis
  • Compressive neuropathy ("bracelet syndrome")
  • Intersection syndrome
  • Snapping Extensor Carpi Ulnaris
  • Vaughn Jackson syndrome
• General
  • Hand and finger dislocations
  • Hand and finger fractures
  • Hand and finger infections
  • Gout and pseudogout
  • Hand and finger tendon injuries
  • High-pressure injection injury
  • Osteoarthritis
  • Rheumatoid arthritis
  • Ring removal

Evaluation

Fingertip Zones

• Zone I - Distal to tip of phalanx
• Zone II - Between tip of phalanx and lunule
• Zone III - Proximal to lunule

Management

No exposed bone or nail bed involvement

• Zone I injuries - treat conservatively with serial dressing changes alone
  • Cover wound with non-adherent dressing
  • Instruct patient to soak fingertip in antibacterial soap-added water for 10min QD and then reapply non-adherent dressing
  • Follow up with primary care provider in 2d
  • Most will have epithelialization in approximately 1 month

Exposed Bone

• Zone II injuries
  • Consider hand surgery consult
  • Rongeur bone if bony protuberance
  • Wound closure with flap
  • Follow up with hand surgery in 3-5d
  • Healing time 3-6wks
• Zone III injuries
  • Consult hand surgery if available
  • May require distal phalanx amputation
  • Consider treating like Zone II
  • Healing time 3-6wks

See Also

• Finger amputation
• Distal phalanx (finger) fracture