Chapter 104. Nail Bed Repair

The fingertip, the most sensitive area of the hand, is often our first contact with the environment. It has important functional roles in grasping and pinching, in addition to its sensory and cosmetic functions.1,2 The fingernail protects the fingertip and provides increased sensation to the volar pulp.3 However, it also conceals the true extent of fingertip injuries. Hand injuries, with the fingertips most frequently involved, are second only to back injuries as the most common occupational injuries resulting in loss of work days.4 Hence, it is important for the Emergency Physician to evaluate the full extent of the injury, to assess potential disabilities, and to recognize the need for prompt referral to a Hand Surgeon.

The fingernails are frequently injured due to their anatomic location and their functional role. Immediate primary repair is the ideal management when these injuries involve the nail bed and surrounding skin fold structures.3,5 Careful repair is necessary to avoid functional impairment and cosmetic derangement of the nail plate.6 The following discussion will refer primarily to the fingernail. The toenail has less importance, both cosmetically and functionally, as grasp and pinch are not needed. However, all the principles and recommendations made also apply to the toenail.7

Knowledge of the anatomy of the nail unit enables the Emergency Physician to recognize the types of injuries and provide anticipatory guidance of the consequences of these injuries to the patients. The “perionychium” or the nail unit consists of the nail fold, the nail plate, nail bed, and the hyponychium (Figure 104-1).1,2

The nail plate enhances the sensibility of the fingertip by applying a counterforce to the pulp space nerve endings.3 The digital tip and the nail plate also function in unison to smoothly coordinate normal pinch and grasp, which are important for picking up fine objects such as coins and pins.3,8

The nail plate is comprised of compacted, flattened, and elongated anucleated cells that originate from cornified epithelial cells.9 There are three atomic sites where these cells exist.5,8 The nail bed contains two of the sites: the sterile matrix and the germinal matrix.8 The other location is the dorsal roof matrix (Figure 104-1A). Of these, the germinal matrix is the most important for normal nail growth.5 The germinal matrix is responsible for approximately 90% of the nail plate by volume.8 The sterile matrix is responsible for a small percent of the nail plate by volume and varies from individual to individual. This cell production accounts for the nail plate being thicker at its distal tip compared to its proximal origin.8 The nail cells from the dorsal roof matrix are small in number and form a very thin layer on the surface of the nail plate. These cells are responsible for the shine of the nail. If the dorsal roof is destroyed, the nail will lose its shine and become dull.

Skin overlies the nail plate proximally and laterally (Figure 104-1B).9 The proximal skin fold is referred to as the eponychium. The eponychium protects the germinal matrix located in the proximal nail bed and is the home of the dorsal roof matrix. The skin immediately over the dorsal roof is called the nail wall.8 The lateral skin folds, the adjacent cutaneous areas, and the adjacent nail bed (germinal matrix and sterile matrix) are collectively referred to as the perionychium (Figure 104-1B).6,8,9 The lunule is the pale arc just distal to the eponychium and roughly corresponds to the location of the germinal matrix.1,2,8,9

The nail bed is comprised of the germinal matrix proximally and the sterile matrix distally. The borders of the nail bed are the proximal nail fold, the lateral nail folds, and the hyponychium distally. The hyponychium is the thick layer of cells at the junction of the distal nail bed (sterile matrix) and the fingertip skin.8 It is located just under the distal free margin of the nail plate (Figure 104-1A). The hyponychium serves as a barrier preventing the delicate nail bed from exposure to bacteria and fungi.8

The rate of nail growth varies from finger to finger, from individual to individual, and varies with age.3,8 Nail growth is fastest between 4 and 30 years of age and after 80 years of age. Fingernails grow four times faster than the toenails.1 A new nail takes a minimum of 4 months to grow, and even longer following an injury. Progression of the distal nail occurs at a rate of 0.1 mm/day or 0.5 to 1 mm/week.3,9 This rate varies and is usually faster in fingers than in toes, and faster in the summer months.3 The pressure of new cells being formed leads to the flattening and elongation of the older cells as well as their progression distally.8

The sterile matrix is more adherent to the nail plate than to the adjacent germinal matrix. Therefore, avulsions involving nail bed tissue are more likely to occur at the sterile matrix.8,10,11 Conversely, the nail plate is loosely held to the germinal matrix. This accounts for the peculiar injury of avulsions of the proximal nail plate from the proximal nail fold while the distal nail plate remains attached (Figure 104-2).

The digital artery supplies the volar radial and ulnar sides of the finger and consistently sends even smaller branches to the proximal nail fold and to the nail bed producing a rich capillary network.1 The small veins of the nail bed, pulp, and lateral nail folds coalesce proximally to form a larger commissural vein that runs lateral to the distal phalanx and a terminal vein that runs dorsal to the distal phalanx. The digital nerve accompanies the digital artery and sends branches beyond the distal interphalangeal joint and into the nail fold, nail bed, and the finger pulp. The extensor tendon attaches itself to the distal phalanx just proximal to the germinal matrix.8,11 The periosteum of the distal phalanx, in turn, closely adheres to the sterile matrix.8

With these anatomic considerations in mind, certain patterns emerge as a result of injury. Avulsions of the nail bed tend to occur in the sterile matrix rather than the less adherent germinal matrix. Another pattern of injury seen is the avulsion of the proximal nail plate from the proximal nail fold while the distal part remains attached to the nail bed (Figure 104-2). Because the sterile matrix closely adheres to the periosteum of the distal phalanx, fractures of the distal phalanx might injure the nail bed producing a subungual hematoma.6 Due to the close proximity of the germinal matrix and the attachment of the extensor tendon, injuries to or repair of these structures might involve the other. A subungual hematoma is a collection of blood between the nail bed and the nail plate. Although a large subungual hematoma may require repair of the underlying nail bed, this is controversial.

Emergency Physicians must consider in each case whether there exists enough damage to require surgical nail bed repair. It is important to note that significant force is required to break, penetrate, or avulse the nail plate.6 Therefore, the fragile nail bed is most likely disrupted if the nail plate is disrupted.

Injuries to the fingertip and nail, if not initially managed correctly, have long lasting functional as well as cosmetic consequences. The most important consideration is functional.9 Normal nail growth after injury requires a smooth nail bed. Therefore, nail bed injuries must be meticulously repaired to prevent cosmetic deformities and functional impairment.9–11 Scar tissue may form between the wound edges if the nail bed is not accurately approximated. This scar tissue will not form the intermediate nail cells responsible for nail adherence.8 Furthermore, loss of the germinal matrix alone will result in permanent loss of the nail plate.5,12 The skin folds surrounding the nail margins must also be preserved.5,11 Failure to do so will result in the painful complication of adhesion formation between the skin fold and the nail bed.5,11 Secondary repair of these spaces, or of the nail bed, requires more complex procedures and are usually associated with a poor outcome.4,10 Therefore, every effort should be made to primarily repair all significant nail bed injuries.

No absolute contraindications exist for primary nail bed repair. Any life-threatening injuries, limb-threatening injuries, and/or uncontrolled hemorrhage must be addressed prior to nail bed repair.

• Povidone iodine or chlorhexidine solution
• Restraining device(s), as necessary
• 10 mL syringe armed with a 27 gauge needle
• Local anesthetic solution without epinephrine, 1% lidocaine or 0.25% bupivacaine
• Digital tourniquet
• #15 scalpel blade on a handle
• Magnification device
• Sterile prefabricated nail, if available
• Nonadherent petrolatum gauze
• 5-0, 6-0, and 7-0 chromic gut (or polyglactin 910 or irradiated polyglactin 910) on a p-3 cutting needle
• 6-0 monofilament nylon sutures
• Needle driver
• Curved hemostat
• Fine scissors or periosteal elevator
• Forceps
• Sterile towels or drapes
• Sterile gloves
• Dry gauze/tube gauze
• Splinting material
• Battery-powered electrocautery device

The use of a digital tourniquet is essential to properly repair a nail bed. Its use provides a bloodless field, which allows for a more meticulous and precise wound approximation. Numerous options are available to use as a tourniquet in the Emergency Department. Home-grown options include the use of a sterile Penrose drain, rubber IV tourniquet, or sterile glove. A sterile Penrose drain or IV tourniquet secured with a hemostat is often used as these items are readily available (Figure 104-3). A sterile glove may be used as a tourniquet (Figure 104-4). Apply a sterile glove onto the patient's hand that is snug or a size one-half smaller than their actual glove size. Cut just the tip off of the glove over the affected finger(s). Roll the cut finger back and onto the proximal phalanx to form the tourniquet (Figure 104-4).

Several commercially produced digital tourniquets are often available in the Emergency Department. The Tourni-cot (Mar Med Co., Grand Rapids, MI) is a sterile, single use, disposable, rubber ring that slides over the fingertip and rolled backward until it rests over the proximal phalanx (Figure 104-5). These come in several sizes to fit the appropriate finger size. The advantage of the Tourni-cot is that it exsanguinates the digit as it is applied. The T-Ring (Precision Medical Devices LLC, San Clemente, CA) is a “one size fits all” digital tourniquet (Figure 104-6). It is a sterile, single use, disposable, rubber diaphragm with a central hole. It slides over the fingertip and is pushed backward until it rests over the proximal phalanx. The T-Ring also exsanguinates the digit as it is applied.

The first step in the evaluation of fingertip injuries is obtaining a thorough history. The mechanism of injury can provide some clues to the type and extent of injuries as well as amount of contamination to be expected. Other pertinent information includes age, hand dominance, occupation or hobbies, comorbidities, and tetanus vaccination status. All significant injuries to the fingertip should be evaluated radiographically for fractures. The management of fingertip injuries may differ in the presence of a fracture. Thoroughly evaluate and document a complete neurovascular examination, tendon function and intactness, and ligamentous stability of the joints. Ascertain the patient's tetanus immune status and administer prophylaxis if required.

It is important to explain both the risks of doing the procedure and of not doing the procedure. Document this conversation and obtain an informed consent. Place the patient on a gurney with the hand on a bedside procedure table in a well-lit area. Be prepared to use age-appropriate sedation or to apply appropriate restraints for children.11 Procedural sedation may be necessary in patients who are agitated, uncooperative, or require extensive repair. Apply a type of magnification device if available. This may consist of a head-strap device, a swing arm device, magnification glasses, or loupe magnification glasses.

Anesthetize the injured digit(s). Anesthesia may be achieved with a digital block or a metacarpal block when only a single digit is involved.6 Lidocaine (1% or 2%) can provide pain relief of up to 3 hours. For longer analgesia, use 0.5% bupivacaine. Although recent studies have shown that the practice of using lidocaine with epinephrine for digital blocks is safe, this is still controversial and many do not advocate its use.13–15 Multiple metacarpal blocks or an axillary nerve block may be performed if multiple digits are involved.6 Please refer to Chapter 126 for the details regarding regional nerve blocks.

Thoroughly clean the hand of any dirt and debris. Apply povidone iodine or chlorhexidine solution and allow it to dry.16 Irrigate the wound with sterile saline. If the nail plate has been avulsed, irrigate it with a dilute povidone iodine or chlorhexidine solution followed by a gentle rinse with sterile saline. It is important not to scrub the undersurface of the avulsed nail plate because adherent squamous tissue may be destroyed.6

A bloodless field is desired and, in many cases, necessary. Apply a digital tourniquet as described in the “Equipment” section above.6 If available, a pneumatic tourniquet may be placed on the arm instead of using the digital tourniquet. The pneumatic tourniquet is especially helpful when the patient has fractures or lacerations of the proximal digit that preclude the use of a digital tourniquet. Avoid using a blood pressure cuff, as these tend to deflate during use. As with all tourniquets, limit the amount of time in which the tourniquet is in place. Create a sterile field by applying sterile towels.

Adhering to certain principles will improve the outcome when repairing nail beds. A smooth and flat nail bed is necessary to the normal growth of the nail and should be the primary goal in any repair. Avoid or severely limit the amount of debridement.5 The germinal matrix must be meticulously repaired and the proximal nail fold, the eponychium, preserved or that space is obliterated within a few days and result in adhesions or abnormal nail growth.5 Thoroughly clean and replace the nail plate whenever possible. This will preserve the nail folds surrounding the nail bed, allow the nail plate to serve as a splint for fractures, and act as a protective cover for the healing nail bed.6 Treatment goals also include preservation of length and sensation of the fingertip, early mobilization, prevention of joint contractures, and attention to cosmesis.4,17

The technique of nail bed repair depends upon the type of injury as well as which structures are involved. Various classification schemes, such as the nature of injury or anatomic location, have been developed to categorize fingertip injuries and guide treatment. Nail bed injuries are classified as simple lacerations, crushing lacerations, avulsion-lacerations, lacerations with associated fractures, lacerations with loss of skin and pulp, and fingertip amputations.2,12

Nail Plate Removal

A significant force is required to break the nail plate. The nail plate should be removed to visualize the underlying nail bed if the nail plate is damaged or avulsed, or the lateral skin folds lacerated as an associated nail bed injury is highly likely. Removal of the nail plate is unnecessary in minor injuries where the nail plate is not damaged and still attached to the nail folds.

Remove the nail plate to repair nail bed injuries or to inspect the nail bed for potential injuries (Figure 104-7). Insert the closed tips of a fine scissors between the nail bed and the nail plate. A periosteal elevator, if available, can be substituted for the scissors. Hold the scissors parallel to the long axis of the finger. Slightly angle the tips of the scissors toward the nail plate to prevent any damage to the nail bed.11 Advance the tips of the scissors 1 to 2 mm. Open the blades of the scissors to separate the nail bed from the nail plate. Close the blades of the scissors. Continue to advance the tips of the scissors in 1 to 2 mm increments and separate the nail bed from the nail plate. Stop advancing the scissors when the tips of the blades are at the level of the eponychium. Firmly grasp the nail plate with a hemostat. Pull the nail plate parallel to the long axis of the finger to completely remove it from the finger.

Making two linear incisions with a scalpel at 90° from the eponychial edge will allow greater exposure to the germinal matrix for repair (Figure 104-8).7 This allows the eponychium to be folded or sutured back and therefore increase exposure of the germinal matrix.2,17

Simple Lacerations

Simple lacerations are caused by localized blows to the nail plate. After removing the nail plate and exposing the nail bed, repair the laceration meticulously using 6-0 or 7-0 chromic gut or irradiated polyglactin 910 sutures.2,6,17 Minimize debridement as much as possible to avoid scarring that will result in nonadherence or splitting of the nail plate. Repair any skin lacerations adjacent to the nail bed using 6-0 or 5-0 monofilament nylon sutures.5 Nail fold lacerations may require repair in layers in order to preserve these spaces.9

Crushing Lacerations

The second type of injury is a crush injury with resultant lacerations. Crushing injuries may produce stellate lacerations and fragmentation of the nail bed (Figure 104-9A). Attempt to meticulously repair the fragmented nail bed using 6-0 or 7-0 chromic gut or irradiated polyglactin 910 sutures to achieve precise approximation and the smoothest result possible (Figure 104-9B).6

Avulsion-Lacerations

The third type of nail bed injury is the avulsion-laceration (Figure 104-10A). These injuries are more complex than the previously described injuries. Distal nail bed avulsions simply require petrolatum gauze to be placed over the injury followed by sterile gauze. Suture the petrolatum gauze and sterile gauze in place using 5-0 or 6-0 nylon suture for 10 days to allow the wound to heal by second intention (Figure 104-10B).5,17 Avulsion-laceration injuries may require consultation with a Hand Surgeon depending on the amount of tissue involved and whether the germinal matrix is involved.6,11,12 More severely damaged nail beds with a large amount of avulsed tissue usually require dermal grafts or split-thickness matrix grafts.6

Small fragments of avulsed nail bed may remain attached to the nail plate. These may be simply treated by carefully replacing the nail plate in its anatomic position.18 Larger segments of avulsed nail bed that remain attached to the nail plate should be repaired (Figures 104-11A & B). Gently shave away the nail bed from the nail plate with a #15 scalpel blade (Figure 104-11C). Replace the avulsed nail bed and suture it in place with 5-0 or 6-0 chromic gut or irradiated polyglactin 910 sutures (Figure 104-11D).10,18 Apply a petrolatum gauze dressing and replace the nail plate.

A special type of avulsion injury occurs when there is a crush injury to the distal fingernail. This results in an avulsion of the proximal nail plate with or without involvement of the germinal matrix (Figure 104-2). The proximal nail plate is less adherent to the nail bed and can be pulled out from under the eponychium (Figure 104-2). Remove the nail plate if the proximal nail plate is avulsed without involvement of the germinal matrix. Clean the nail plate and nail bed with sterile saline. Replace and secure the nail plate.

More often with these crush injuries the germinal matrix is avulsed as well. In these cases, the germinal matrix should be replaced with a series, usually three, of 6-0 nylon simple interrupted or horizontal mattress sutures (Figure 104-12).5,6,10 Place all three sutures before returning the nail bed to its proper location. Making two linear incisions with a scalpel at 90° from the eponychial edge will allow exposure to the germinal matrix for repair (Figure 104-8).7 This allows the eponychium to be folded or sutured back and therefore increase exposure of the germinal matrix. Place a piece of petrolatum gauze between the eponychium and the germinal matrix after the repair (Figure 104-12B). Larger germinal matrix avulsions require consultation with a Hand Surgeon for grafting.2,6,11,17

Lacerations with Associated Fractures

The fourth type of nail bed injury is lacerations associated with fracture(s). Approximately 50% of nail bed injuries have an associated phalangeal tuft fracture.19 The nail bed laceration should be repaired as previously described and the fracture addressed as a separate entity.5 It is important to remember that the sterile matrix is closely adherent to the dorsal periosteum of the distal phalanx. Therefore, fractures require precise anatomic reduction in order for normal nail bed healing and nail plate growth to take place.6,10,12 Replacing the nail plate and splinting the finger after repairing the nail bed laceration is often enough to reduce these fractures. Occasionally, fixation may be employed by a Hand Surgeon using Kirschner wires to prevent rotation of the bony fragments.2,6

Lacerations with Skin Loss and Fingertip Amputations

The final two types of injury are lacerations with loss of skin and pulp, and fingertip amputations. They can be further classified according to zones based upon the anatomic level of amputation (Figure 104-13).3 Zone I injuries occur distal to the bony phalanx. These do not result in the loss of function and rarely result in a cosmetic deformity. Management consists of cleansing, placing topical antibiotic ointment over the injured area, and then applying a layer of petrolatum gauze. This should be followed by a sterile dressing and a splint. Zone II injuries occur distal to the lunule and over the bony phalanx. These injuries often have exposed bone. Zone III injuries occur proximal to the distal end of the lunule. Zone II and Zone III injuries should be managed in consultation with a Hand Surgeon. Either type of injury may require reconstruction with a pedicle flap and/or skin grafting.3

Trephination for a Subungual Hematoma

A subungual hematoma is a collection of blood under the nail plate caused by blunt trauma to the fingertip. The nail bed is usually crushed or lacerated with resultant extravasation of blood into the plane between the nail plate and the nail bed.11 As pressure builds up, compression of nail bed nerves occurs and often causes significant pain. Usually this pain is what causes the patient to seek medical attention. The management of subungual hematomas is discussed separately because these injuries are typically minor and treated by simple trephination. A complete discussion of the management of subungual hematomas can be found in Chapter 102.

It is generally accepted that subungual hematomas <50% of the nail plate may be managed conservatively by simple trephination (puncture) of the nail plate.2,5,6,11,17,20,21 This allows for drainage of blood and immediate pain relief. No anesthesia is usually necessary for this procedure. Ideally, this is accomplished with the use of an electrocautery device creating a 3 to 4 mm hole in the nail plate overlying the hematoma. The nail plate should be clean and dry for this procedure. If an electrocautery device is not available, a heated paperclip may be used.5 Refer to Chapter 102 for more complete details of the procedure.

Some controversy exists over the management of subungual hematomas >50% of the nail plate. The concern is that a larger hematoma may hide an occult laceration that requires repair in order to avoid the complication of step-off with subsequent ridging as the new nail grows back. Some authors feel that it is impossible to accurately assess the amount of damage beneath a subungual hematoma unless the nail plate is removed to directly inspect the nail bed.6,21 These authors noted that subungual hematomas that have separated greater than 50% usually have lacerations that require repair. Another study found that a subungual hematoma with more than 50% separation had a 60% incidence of having a nail bed laceration that required repair and up to a 95% incidence when there was an associated phalanx fracture.21 In contrast to these studies, a prospective study found no complications at 6 months follow-up for subungual hematomas treated by electrocautery trephination alone.2,20 This was regardless of the size of the subungual hematoma or the presence of a fracture. These authors feel that removing the nail plate and attempting repair may actually cause further trauma to the nail bed.20

It was previously recommended that radiographs be obtained to rule out a fracture for all hematomas larger than 50% of the nail plate. A newer study found no correlation between the size of the hematoma and the presence of fractures.20 If a fracture is suspected, have a low threshold to obtain plain radiographs prior to evacuating the hematoma.

In summary, most subungual hematomas may be treated by simple nail trephination using an electrocautery device. This procedure will lead to beneficial drainage only if done before 36 to 48 hours from the time of the injury.11 The clinical benefit of nail bed repair with larger subungual hematomas is controversial. It may be prudent to maintain a lower threshold for nail bed repair with a larger subungual hematoma, particularly if an ideal cosmetic outcome is desired.

Whenever possible, the nail plate should be replaced after repairing any of the above-mentioned injuries. The nail plate covers the sensitive nail bed and protects it from injury, maintains the proximal nail fold (eponychium) to allow for growth of a new nail, and splints the nail bed. In order to accomplish the best outcome, place a hole in the center of the nail plate to allow for fluid drainage.11 Make one or two holes in the lateral aspects of the nail plate. Suture the nail plate in place using 5-0 nylon sutures through the lateral skin folds (Figure 104-14).6,10,11 These sutures should remain in place for 7 days. An alternative to suturing the nail plate in position is to use tissue adhesive. After replacing the nail plate, apply tissue adhesive along the eponychium and lateral nail folds at the area where they overlap the nail plate. An artificial nail may be used if the original nail plate is not available. The potential problem with sterile prefabricated nails is that there exists an increased risk for infection and a risk of erosion into the nail bed or nail folds.6 The editor recommends petrolatum gauze be used to maintain the nail fold structures when the original nail plate is not available or significantly damaged (Figure 104-15).

After repair of the nail bed, the digit(s) involved will need to be bandaged in order to protect it from infection, moisture, and trauma. The application of becaplermin, recombinant human platelet-derived growth factor, has shown to improve outcomes.22 This substance is not routinely used in the Emergency Department and should be applied after consultation with a Hand Surgeon. Place petrolatum gauze over the nail bed to avoid adherence from secretions. Apply a tube gauze dressing followed by a digital aluminum splint.3 Movement of the distal interphalangeal joint should be restricted for 7 to 10 days with a splint.6 For infants and young children, the entire hand should be dressed. If petrolatum gauze was used to keep the proximal nail fold (eponychium) open, it should be removed in 5 to 10 days.6 Petrolatum gauze used to keep open the lateral nail folds (perionychium) should remain in place for 10 days.5 Any sutures placed in the skin structures or nail folds should be removed in 7 to 10 days.5

Prophylactic antibiotics are not routinely required. They are recommended for large avulsions, amputations, and associated fractures when there is contamination with organic material.6 Topical antibiotics may be applied to Zone I fingertip amputations. All injuries require a wound check in 24 to 72 hours.3,5,6 The patient's tetanus immune status should be determined and prophylaxis administered if required. The hand should be elevated whenever possible. Narcotic analgesics may be prescribed as needed for pain control.

It is important to explain to the patient that regeneration of a new nail may take up to 6 to 12 months.6 Warn the patient that as the new nail forms, it may look irregular and snag on cloth or string objects.6 The patient should trim and file the leading edge of the new nail once it extends past the hyponychium in order to avoid snagging.

The complications associated with failure to repair or improper repair of a nail bed can be either functional, cosmetic, or both. The more serious complications are those which impair function or cause pain. There are basically seven complications that may arise. These exclude the infectious complications (abscess formation, cellulitis, and lymphangitis) that are inherent to all wounds. The occurrence of osteomyelitis from these injuries is rare, even with open fractures. The seven complications are loss of the nail, a split nail, a nonadherent nail, an ingrown nail, a malaligned nail, wide nails, and narrow nails.12

The complete loss of a nail could result in significant functional impairment to the fingertip as well as an abnormal looking fingertip. Complete nail loss occurs when there is complete disruption of the germinal matrix, either by significant avulsion of the matrix or amputation. Remember that if the germinal or roof matrices are not repaired, the pouch deep to the proximal skin fold (eponychium) is obliterated within a few days.20

A split nail occurs when the germinal matrix is improperly approximated.5,6,12 A wide scar will result that will not form a new nail. Subsequently, a split nail develops. This can be avoided by the careful approximation of the nail bed with sutures.

A nonadherent nail occurs when the nail bed is not repaired and granulation tissue forms secondarily. The nail plate will not adhere at the site of the granulation tissue as well as distal to the granulation tissue.12 The nail can snag and be exposed to repeated tears once the nail plate loses adhesion to the nail bed.

The nail plate may ingrow if the lateral skin folds or sulci are not maintained and kept open.12 Adhesions that form between the skin and nail bed can be very painful when the new nail tries to grow through that space.5 Ingrown nails also have the long-term problem of a higher rate of infections (paronychia). This can be avoided by the replacement of the nail plate or the placement of petrolatum gauze to elevate the lateral nail fold from the nail bed.

The nail plate will grow in a malaligned direction if the matrix is displaced or repaired in such a manner that it is improperly aligned.12 Functional impairment and cosmetic deformity may ensue depending upon the degree of this misdirected growth.

Wide nails often result from a crush injury with a tuft fracture.12 Separated bony fragments leave the nail bed flatter and wider. Narrow nails occur when a central avulsion-laceration is not repaired. Scar tissue forms in the center and allows the intact lateral portions to contract toward each other.12 The new nail subsequently becomes narrow and thick.

Tubular gauze dressings are commonly applied after the repair of a nail bed. When improperly placed, tubular gauze dressings can result in significant injury.23,24 This includes digital ischemia that may be permanent and require an amputation. Tubular gauze dressings should not be placed by healthcare personnel not trained in their proper application.

Nail bed injuries are common and may result in a cosmetically deformed or functionally impaired fingertip. Complications may occur even with precise repair. The treatment of choice is immediate primary repair of the nail bed and surrounding structures. Remember to minimize any debridement and to replace the nail plate whenever possible. Injuries with associated fractures and simple subungual hematomas are managed separately from the nail bed injury. Always be thorough and meticulous when repairing nail bed injuries to provide the best possible outcome. Finally, know when to consult with a Hand Surgeon.