10.03 Nail Root Dislocation

agk’s Library of Common Simple Emergencies

Presentation

The patient has caught his finger in a car door or dropped a heavy object like a can of vegetables on a bare toe, with the edge of the can striking the base of the toenail and causing a painful deformity. The base of the nail will be found resting above the eponychium instead of in its normal anatomical position beneath. The cuticular line that had joined he eponychium at the nail fold will remain attached to the nail at ts original position.

What to do:

• Take an x ray to rule out an underlying fracture (which may require reduction as well as protective splinting.)
• Anesthetize the area using a digital block.
• Lift the base of the nail off the eponychium, and thoroughly cleanse and inspect the nail bed. Minimally debride loose cuticular tissue and test for a possible avulsion of the extensor tendon.
• If bleeding is a problem, establish a bloodless field using a Penrose drain to wrap and tourniquet the finger.
• Repair any nailbed lacerations with a fine absorbable suture like 7-0 or 6-0 Vicryl.
• Reinsert the root of the nail under the eponychium.
• Reduce any underlying angulated fracture.
• If the nail tends to drift out from under the eponychium, it can be sutured in place with two 4-0 nylon or polypropylene stiches in the corners.
• Any non-absorbable sutures should be removed after one week.
• Cover the area with a finger tip dressing and splint any underlying fracture.
• Provide tetanus prophylaxis.
• Followup should be provided in 3-5 days. Instruct patients to return immediately if there is increasing pain or any other sign of infection.
• Prescribe an analgesic like acetaminophen and hydrocodone.

What not to do:

• Do not ignore the nail root dislocation and simply provide a finger tip dressing. This is likely to lead to continued bleeding or to a later infection because tissue planes have not been replaced in their natural anatomic position.
• Do not debride any postion of the nailbed, sterile matrix or germinal matrix.

Discussion:

Because the nail is not as firmly attached at the base or lunula as it is to the distal nail bed, impact injuries can avulse only the base (nail root) leaving it lying on top of the eponychium. It may be surprising that this injury is often missed but at first glance, a dislocated nail can appear to be in place, and without careful inspection, a patient can return from radiology with negative x rays and be treated as if he only had an abrasion or contusion. The attachment of the cuticle from the nailfold of the eponychium to the base of the nail forms a constant landmark on the nail. If any nail is showing proximal to this landmark it indicates that the nail is not in its normal position beneath the eponychium.

Illustration

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from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES ©
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