NAILBED INJURY

Introduction

The fingernail is a sophisticated appendage that is essential for both the aesthetics and functioning of the finger, as it protects the dorsum of the fingertip, enhances tactile sensitivity, and assists with fine pick-up and pinching tasks.1 Fingertip injuries are among the most common traumatic conditions seen by hand surgeons. Treatment typically consists of nail plate removal and nail bed repair or trephination, both of which prevent nail loss and deformity when executed properly.2,3

Pathophysiology

  • Blunt or sharp trauma from a crushing injury to the fingertip (eg, from a heavy object, car accident, slammed door, industrial workplace mishap, or sports game) causes compression of the nail matrix, which leads to a simple or complex nail bed laceration; a cut directly to the nail bed may also be responsible1,3,7
  • Sharp lacerations can occur when objects land with enough force to penetrate the nail plate3
  • Avulsion injuries from a crushing or grinding force are also possible and often result in partial loss of the nail bed3
  • Subungual hematoma commonly occurs after a crushing injury and nail bed trauma7

Related Anatomy3

  • The perionychium consists of the nail and surrounding structures, including the hyponychium, nail bed, and nail fold
  • The nail bed is the skin that lies directly underneath the nail plate and above the distal phalanx
  • The eponychium refers to the soft tissue proximally on the dorsum of nail continuing to the dorsal skin
  • The white arc on the nail just distal to eponychium is the lunula; the nail bed distal to this is the sterile matrix and proximal to that is the germinal matrix
  • The nail fold consists of the germinal matrix and eponychium

Incidence and Related Conditions

  • Damage to the nail bed is estimates to occur in 15–24% of all fingertip injuries4,5,6
  • Approximately 50% of nail bed injuries are associated with distal phalangeal fracture
  • Subungual hematoma
  • Eponychial loss
  • Onycholysis
  • Bony irregularities
  • Ridged nail
  • Split nail3
  • Pincer nail
  • Nail plate disruption
  • Nail matrix laceration
  • Partial or complete fingertip amputation7
Clinical Presentation Photos and Related Diagrams
Nail Bed Lacerations
  • Complex nail bed laceration through germinal matrix (1) and sterile matrix (2) with pulp laceration  and exposed distal phalanx.
    Complex nail bed laceration through germinal matrix (1) and sterile matrix (2) with pulp laceration and exposed distal phalanx.
Symptoms
Pain with loss of finger function
Nail deformity
Dark nail with discoloration secondary to a subungual hematoma
Typical History

The typical patient is a 28-year-old male. Upon exiting his parked car on steep hill, the car door shut and caught his right long finger, which immediately damaged his fingertip. The trauma from the slammed door resulted in a simple laceration to the middle one-third of his nail bed and an associated fingertip injury. He experienced a throbbing pain in his injured finger and had difficulty performing certain tasks that required fine gripping skills, such as holding a pen to write.8  He was seen in the emergency room where the remaining nail plate was removed and the nail bed repaired with aborbable sutures.  The nail plate was sutured in place to splint the nail bed repair and to keep the nail fold open.

Positive Tests, Exams or Signs
Work-up Options
Images (X-Ray, MRI, etc.)
Fractures Associated with Nail Bed Lacerations
  • Distal phalanx shaft anf tuft fracture (arrow) associated with nail plate loss and nail bed laceration
    Distal phalanx shaft anf tuft fracture (arrow) associated with nail plate loss and nail bed laceration
Treatment Options
Conservative: 
  • If the X-ray does not reveal a fracture of the distal phalanx, the patient is asymptomatic and subungual hematoma covers <25% of the nail surface area, no intervention may be needed3,7
Operative: 
  • Surgical intervention is typically necessary if the subungual hematoma covers ≥25% of the nail surface area, the patient is in significant pain, and/or the distal phalanx is fractured
  • Nail bed trephination
    • May be sufficient treatment if the subungual hematoma covers 25-50% of the nail surface area and the nail plate is intact
    • Electrocautery is used to perforate the nail with a large enough hole to drain the hematoma; multiple holes may be necessary to facilitate adequate drainage
  • Nail plate removal and nail bed repair
    • Commonly recommended if the subungual hematoma covers >50% of the nail surface area9
    • Particularly necessary if distal phalanx is also fractured7
    • Careful repair should be performed under magnification using 6-0 or smaller absorbable sutures or 2-octylcyanoacrylate2,9
    • The nail may or may not be subsequently replaced between the eponychial fold and underlying matrix, although it is recommended in cases of distal phalanx comminuted fracture3
    • Splinting of eponychial fold
  • Percutaneous pinning
    • For unstable distal phalanx fractures
  • Nail bed graft
    • Recommended with occurrence of nail bed loss
    • Can be harvested from the adjacent nail bed when the loss is very small or from the great toenail when it is large3
Complications
  • Split nail
  • Hook nail
  • Loose nail plate
  • Deformed nail with ridges etc
  • Infection especially chronic fungal infection
Outcomes
  • Nail plate removal and nail bed repair elicit good-to-excellent outcomes and prevent long-term cosmetic and functional disability2,8
  • Patients with severe crush injuries, avulsion injuries, and multiple areas of injury generally report poorer overall outcomes8
  • If meticulous repair of nail bed laceration is not obtained, nail deformity is likely to occur2
  • Nail bed trephination has also been associated with a low infection rate and a good cosmetic outcome7
  • Accompanying fracture appears to have little effect on final appearance of nail8
Key Educational Points
  • Nail bed repair is a technically difficult procedure, as it uses very small absorbable sutures under magnification to repair uneven, often complex, nail bed fissures, some of which are associated with underlying fractures9 
  • Significant controversy remains regarding the appropriate management of nail bed injuries, as some believe trephination alone can be adequate to treat subungual hematomas that cover >50% of the nail surface area7
  • Nail plate regeneration is a slow process with nail growing on average .1mm per day
Practice and CME
References

Cited

  1. Inglefield CJ, D'Arcangelo M, Kolhe PS. Injuries to the nail bed in childhood. J Hand Surg Br 1995;20(2):258-61. PMID: 7797986
  2. Strauss EJ, Weil WM, Jordan C, Paksima N. A prospective, randomized, controlled trial of 2-octylcyanoacrylate versus suture repair for nail bed injuries. J Hand Surg Am 2008;33(2):250-3. PMID: 18294549
  3. Bharathi RR, Bajantri B. Nail bed injuries and deformities of nail. Indian J Plast Surg 2011;44(2):197-202. PMID: 22022029
  4. Shepard GH. Treatment of nail bed avulsions with split-thickness nail bed grafts. J Hand Surg Am 1983 Jan;8(1):49-54. PMID: 6827053
  5. Illingworth CM. Trapped fingers and amputated finger tips in children. J Pediatr Surg 1974;9(6):853-58. PMID: 4473530
  6. Usal H, Beattie TF. An audit of hand injuries in a paediatric accident and emergency department. Health Bull (Edinb) 1992;50(4):285-7. PMID: 1526770
  7. Mignemi ME, Unruh KP, Lee DH. Controversies in the treatment of nail bed injuries. J Hand Surg Am 2013;38(7):1427-30. PMID: 23751325
  8. Zook EG, Guy RJ, Russell RC. A study of nail bed injuries: causes, treatment, and prognosis. J Hand Surg Am 1984;9(2):247-52. PMID: 6715836
  9. Fehrenbacher V, Blackburn E. Nail bed injury. J Hand Surg Am 2015;40(3):581-2. PMID: 25499844

New Articles

  1. Mignemi ME, Unruh KP, Lee DH. Controversies in the treatment of nail bed injuries. J Hand Surg Am 2013;38(7):1427-30. PMID: 23751325
  2. Fehrenbacher V, Blackburn E. Nail bed injury. J Hand Surg Am 2015;40(3):581-2. PMID: 25499844

Reviews

  1. Strauss EJ, Weil WM, Jordan C, Paksima N. A prospective, randomized, controlled trial of 2-octylcyanoacrylate versus suture repair for nail bed injuries. J Hand Surg Am 2008;33(2):250-3. PMID: 18294549

Classics

  1. Zook EG, Guy RJ, Russell RC. A study of nail bed injuries: causes, treatment, and prognosis. J Hand Surg Am 1984;9(2):247-52. PMID: 6715836
  2. Shepard GH. Treatment of nail bed avulsions with split-thickness nail bed grafts. J Hand Surg Am 1983 Jan;8(1):49-54. PMID: 6827053
  3. Stevenson TR. Fingertip and nailbed injuries. Orthop Clin North Am 1992;23:149-159. PMID:1729663