Chapter 35. Nail Trephination

• Subungual hematoma with pain.

• Some experts suggest that nail removal and repair should be prompted by the percentage of nailbed involved (eg, greater than 25–50%), but this is not supported in the literature.

• Procedure is limited to simple hematomas, not complex crush injuries with associated fractures or nailbed injuries.

• Immunosuppression.

• Do not trephinate artificial acrylic nails using cautery (flammable).

• Do not prepare the nail with alcohol (also flammable).

• 10% povidone-iodine (or equivalent).

• Sterile gloves and gauze.

• Single-use, disposable electrocautery device (sterile) is preferred.

• A needle or metal paperclip heated in a flame is an alternative to electrocautery. A metal paperclip is preferred because it is blunt and will do less damage if inserted too far.

• Another alternative is to use either an #11 blade or 18- or 20-gauge needle in a twisting motion to drill the nail.

• Infection (very rare).

• Pain (if done correctly, procedure should provide pain relief).

• Nail deformity (rare, and associated with more complex injuries).

• Immobilization is important for young children; movement during the procedure can lead to injury to the nailbed or fingertip.

• Hide the cautery device from view of the young child until just before the procedure. Explain the procedure to older children, emphasizing that holding still will prevent pain.

• Do not mistake the pain of an underlying fractured phalanx for the pain of a hematoma.

• Obtain a radiograph if indicated by history or examination.

• Consider nail removal or specialist consultation for management and follow-up when any of the following is present:

• • The nail or nailbed is disrupted.

  • There is a displaced fracture of the phalanx.

  • There is substantial periungual blood (suggesting eponychial injury).

• Prepare the nail with a 10% povidone-iodine solution.

• Place the hand on a sterile surface.

• The nail is firmly adherent to the underlying nailbed (Figure 35–1).

• A hematoma in this space that cannot drain spontaneously causes pain that is sometimes severe.

• The nail itself is insensate, but the nailbed is very sensitive.

• The key to a pain-free procedure is to puncture the nail without entering the nailbed.

• With the hand properly positioned and immobilized (if necessary), the cautery device is heated and then applied to the nail in the center of the hematoma area.

• Little or no pressure is required to penetrate the nail, particularly in small children with thin nails.

• Immediately upon entering the subungual space, blood will escape and a sizzling sound will be heard (from the blood hitting the cautery blade).

• Immediately withdraw the blade.

• Slight pressure will express more of the remaining fluid.

• Older hematomas may no longer ...