As a general principle, when the nail bed is avulsed, it should be always repositioned to obtain anatomical reconstruction of the fingernail. Thus, when a fragment of the nail bed remains attached to the undersurface of the avulsed nail, it should be replaced as a composite free graft. If the avulsed fragment is not available because of loss or destruction, conservative treatment or reconstructive techniques can be considered. Conservative techniques are based on the observation that the nail bed has a regenerative potential that allows for complete nail repair in about 6 weeks [17]. In his study, Ogunro [14] reported that when the residual nail bed is effectively covered, in order to prevent drying and maintain a local environment suited for tissue regeneration, normal nail growth may be obtained.
Reconstructive techniques can be used when larger nail-bed defects are observed, but these procedures may be demanding and not immediately executable in all the orthopedic and plastic surgery centers. There are several options for reconstructing sterile and matrix defects, including split-thickness or full-thickness grafts, rotational flaps, and composite grafts. The choice of donor site is made according to the extent of the lesion. It is possible to select: (a) nail bed from uninjured areas of the involved finger; (b) a bank finger when the injured finger is not available for replantation; (c) uninjured fingers or the big toe for larger defects (it may be harvested in an emergency even under local anesthesia). Split-thickness nail-bed graft may be harvested from uninjured areas of the involved finger if the defect is small or from adjacent uninjured finger or toe when larger nail-bed areas are involved. Nail-bed graft can be placed directly on the exposed cortex of the distal phalanx, sutured to the surrounding nail bed, and appropriately dressed [18]. Full-thickness nail-bed grafts have the disadvantage of causing deformity of the donor site and are rarely used except when there are salvageable spare parts that would otherwise be not used [19]. A full-thickness nail-bed graft is necessary, however, when replacing lost germinal matrix to support regeneration of the nail plate or in case of complex injury of the perionychium surrounding the nail bed [20].
The well-vascularized nail bed and matrix enable the use of rotation flap as a proximal or distal pedicled flap for large defects (even 5–6 mm) or bipedicled flap for defects <3 mm. For more complex injuries, some authors suggest nonvascularized composite tissue grafts, combining sterile and germinal matrix and eponychium, usually performed from the second toe. Only 50% have been described as attaining good results, and donor-site sequels are not negligible. Many techniques and variations from the wrap-around flap of Morrison have been reported to allow reconstruction in one setting of combined bone and soft-tissue loss. In those cases, the pedicles are sutured at the level of the proximal interphalangeal joint.