10.04 Finger or toenail avulsion

agk’s Library of Common Simple Emergencies

Presentation

The patient may have had a blow to the nail; the nail may have been torn away by a fan blade or other piece of machinery; or a long hard toenail may have caught on a loop of a shag carpet or other fixed object and been pulled off the nailbed. The nail may be completely avulsed, partially held in place by the nail folds, or adhering only to the distal nail bed. On occasion, an exposed nailbed will have a pearly appearance with minimal bleeding making it seem as if the nail is still in place when actually it has been completely avulsed.

What to do:

• Obtain x rays if there was any crushing or high velocity shearing force involved.
• Perform a digital block to anesthetize the entire nailbed.
• Cleanse the nailbed with normal saline and remove any loose cuticular debris. Although it is acceptable simply to cover the nailbed with a non-adherent dressing, the patient is usually more comfortable with a clean nail or surrogate in place while a new nail grows in. No dressing is truely non-adherent over an exposed naibed. If the nail or artificial stent is not used, then bring the patient back for an early dressing change in one day to prevent adherence.
• If the nail is still tenuously attached, remove it by separating it from the nailfold using a hemostat. Cleanse the nail thoroughly with normal saline, cut away the distal free edge of the nail and remove only loose cuticular debris.
• Inspect the nailbed for lacerations and if present carefully reapproximate with fine (6-0 or 7-0) absorbable sutures.
• Reduce any displaced or angulated fractures of the distal phalynx. If a stable reduction cannot be obtained, consult an orthopedic surgeon for possible pinning.
• Reinsert the nail under the eponychium and apply a fingertip dressing.
• If the nail does not fit tightly under the eponychium, it can be sutured in place at its base.
• If the nail is missing, badly damaged or contaminated, replace it with a substitute. An artificial nail can be cut out of the sterile aluminum foil found in a suture pack or can be cut from a sheet of vaseline gauze. Insert this stent under the eponychium as you would the nail and apply a fingertip dressing after it is in place.
• Leave these stents in place until the nailbed hardens and the stent separates spontaneously.
• Dressings should be changed every three to five days.
• If the wound was contaminated, tissue macerated, pr patient immunocompromised, prescribe three or four days of a first generation cephalosporin as prophylaxis. Fractures of the distal phalynx do not always require antibiotics however.

What not to do:

• Do not dress an exposed nailbed with an ordinary gauze dressing. It will adhere to the nailbed and require lengthy soaks and at times an extremely painful removal.
• Do not ignore nailbed lacerations or fractures of the distal phalanx. The new nail can become deformed or ingrown wherever the bed is not smooth and straight.
• Do not debride any portion of the nailbed, sterile matrix or germinal matrix.

Discussion:

Although the eponychium is unlikely to scar to the nailbed unless there is infection, inflammation, or considerable tissue damage, separating the eponychium from the nail matrix by reinserting the nail or inserting an artificial stent helps to prevent synechia and future nail deformities from developing. The patient's own nail is also his most comfortable dressing. Minimally traumatized avulsed nails can actually grow normally if carefully replaced in their proper anatomic position. A gauze stent left in the nail sulcus will be pushed out as the new nail grows. Complete regrowth of an avulsed nail usually requires four to five months at one milimeter per week.

Illustration

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from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES ©
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