Nailbed injuries are common, with fingertip injuries being the most often seen type of hand injuries. The fingertip is frequently injured because it is the point of interaction between the body and one's surroundings in the majority of activities performed on a daily basis, and it is the most distal portion of the upper extremities.[1, 2, 3, 4, 5, 6]
In addition to long-term cosmetic consequences, injuries to the nail can affect daily living. The nail provides protection for the fingertip, offers the ability to pick up small objects, and plays a role in tactile sensation. It serves as a counter force when the finger pad touches an object; two-point discrimination distance widens substantially with removal of a nail.
Blunt trauma to the fingertip and nailbed requires adequate treatment to prevent secondary deformities and reduce the need for subsequent reconstruction.[7] Delayed or inadequate treatment can result in negative functional and cosmetic outcomes. Peak incidence of fingertip and nailbed injuries is from 4 to 30 years of age. According to Chang et al, 10% of such accidents are treated in the emergency department. In the case of fingertip injuries, the nailbed is injured in 15-24% of cases.[8]
The injured finger can usually be examined without anesthesia, although children or those in severe pain may require a digital block first. A complete examination of sensation (performed prior to a digital block), motor function, and vascular supply is necessary.
A digital block of 1% lidocaine hydrochloride without epinephrine provides anesthesia of sufficient duration for most repairs. Bupivacaine extends anesthesia time 4-8 hours for longer procedures. Children may require procedural sedation and analgesia.
Observe the posture of the fingers, and look for any presence of deformities signifying fracture, dislocation, or tendon avulsion, and the presence of glass, wood, metal, or other foreign body fragments.
Depending on the extent of injury, radiologic evaluation with anteroposterior, lateral, and oblique views of the injured finger(s) may be useful to rule out foreign bodies and fractures or dislocations of the distal finger.[6]
The prophylactic use of antibiotics is indicated, depending on mechanism and extent of injury, such as for crush injuries and human bites or animal bites. Many clinicians prescribe a first-generation cephalosporin when bone or joint is exposed below a nailbed injury.
Small (less than 25% of the nailbed) and painless subungual hematomas require no intervention, as the hematoma will eventually reabsorb. If the subungual hematoma covers more than 25% of the nailbed or is causing pain, the patient should be offered evacuation via trephination or nail removal (see Hand, Subungual Hematoma Drainage).
Lacerations to the nailbed should be repaired using 6-0 or smaller absorbable sutures. Minimal to no debridement should be performed because aggressive debridement may cause undue tension on the repair and results in scarring.
When repairing avulsed nails and nailbeds, if the nail is detached proximally, it must be removed to inspect for any damage to the nailbed.
See the treatment images below.
View Image | Trephination of a subungual hematoma. |
View Image | Nailbed repair. |
Crush and avulsion injuries, as well as injuries associated with distal phalanx fractures, have a worse prognosis.
See 15 Fingernail Abnormalities: Nail the Diagnosis, a Critical Images slideshow, to help identify conditions associated with various nail abnormalities.
To fully appreciate the consequences and treatment of nailbed injuries, reviewing the anatomy of the nailbed and the surrounding tissues is useful.[1, 9, 10, 11]
Nail formation is a collective production by 3 areas of the perionychium:
Longitudinal nail growth takes between 70 and 160 days to cover the entire length of the nail. After an injury, nail growth is stunted or absent for up to 21 days. The nail then grows rapidly for approximately the next 50 days and then slows again before a normal and sustained growth rate resumes. These relative accelerations and slowdowns in nail growth create the characteristic lump that is often observed on most nails that regrow after trauma.
As a result of scar tissue being unable to produce nail material, damage to specific components of the perionychium will lead to characteristic defects during regrowth of the posttraumatic nail. A scar of the dorsal roof of the nail fold creates a dull streak on the nail surface, while a scar of the germinal matrix may cause a split or absent nail, and a scar in the sterile matrix results in a split or nonadherent nail beyond the scar.
The nailbed is supplied by two volar arterial arches that are anastomoses between digital arteries of the finger or toe, just above the periosteum of the distal phalanx. Venous drainage coalesces in the proximal nailbed and proximal to the nail fold and drains over the dorsum of the finger. Abundant lymphatic vessels are present in the nailbed. The perionychium is innervated by the dorsal branches of the paired digital nerves, one to the nail fold, one to the fingertip, and one to the pulp.
The hand is involved in 11-14% of on-the-job injuries and 10% of all accident cases in US emergency departments. However, the exact prevalence of nailbed injuries is unknown since many patients with nailbed injuries do not bother to seek a physician's care for what they perceive as a minor trauma.
Complications of nailbed injuries include nail loss, abnormal growth, nonadherence of new nail, splitting of the nail, soft tissue infection, and osteomyelitis of the underlying distal tuft.
A 3:1 male-to-female predominance of injury exists.
Nailbed injuries occur in people of all ages; however, the most common age group is between 4 and 30 years old. Fingertip injuries account for two thirds of hand injuries in children, and damage to the nailbed occurs in 15-24% of these injuries.[2, 3]
Nailbed injuries generally heal well with appropriate treatment, although it may take months to years for the nail to grow back into the proper shape.
Crush and avulsion injuries, as well as injuries associated with distal phalanx fractures, have a worse prognosis. Injuries that span the entire nailbed or most of the bed and fold also fare worse than those that are isolated to one to two thirds of the nailbed or only to the nail fold and germinal matrix.
All patients should be advised that a deformed nail is a possibility.
New nail growth may take from 3-12 months and even then, it may be misshapen for a longer time.
If problems with new nail growth exist at 6 or 12 months, patients may want to follow up with a hand surgeon for possible scar excision or nailbed revisions.
For excellent patient education resources, visit eMedicineHealth's Skin Conditions and Beauty Center. Also, see eMedicineHealth's patient education article Subungual Hematoma (Bleeding Under Nail).
A complete history for a nailbed injury should include hand dominance, time of the injury, the presence of an associated open wound, previous history of hand injury, tetanus status, occupation and hobbies, and the patient's overall health. All of these aspects of the patient's presentation may affect the treatment plan for the injury. Also, inquire about the circumstances of the accident, as the mechanism of injury has prognostic implications for severity of injury and wound contamination.
Most injuries of the nailbed involve the fingertip versus an isolated nailbed injury (6:1 ratio). The right and left hands are affected equally. However, the long finger is most often affected, since it is usually the last to be pulled from a situation that has the potential to cause trauma. After the long finger, the ring, index, pinky, and thumb are affected in that order. The middle and distal third of the nail are the most frequent sites of injury.
Crush and avulsion injuries as well as injuries associated with distal phalanx fractures have a worse prognosis. Injuries that span the entire nailbed or most of the bed and fold also fare worse than those that are isolated to one to two thirds of the nailbed or only to the nail fold and germinal matrix.
A general examination is necessary to rule out additional injuries.
The injured finger can usually be examined without anesthesia, although children or those in severe pain may require a digital block first. A complete sensory examination (performed prior to a digital block) as well as motor function and vascular supply is necessary. If the nail is avulsed from the nail fold and is unstable, a digital block will usually be necessary to accurately examine the extent of injury. Loupe magnification may be used if necessary.
The presence and extent of devascularized and macerated skin should be noted as the presence of active bleeding, a subungual hematoma, avulsion of the nail, disruption of the nailbed, and any specific pattern of laceration (linear, stellate, flap) of the nailbed if visible. Observe the posture of the fingers, and look for any presence of deformities signifying fracture, dislocation, or tendon avulsion, and the presence of glass, wood, metal, or other foreign body fragments.
Nailbed injuries are often accompanied by subungual hematomas, lacerations to the surrounding skin, crush or avulsion injuries to the distal finger, and associated fractures of the distal phalanx.
A subungual hematoma is a common presentation, and the possibility of an underlying nailbed laceration or injury should always be considered. Lacerations of the nailbed associated with subungual hematomas are most often stellate. Simple lacerations are uncommon unless an accompanying crushing component that was strong enough to collapse the nail through the nailbed and onto the distal phalanx or to fracture the distal phalanx occurred. Fracture of the distal phalanx usually disrupts the matrix but may not break the nail.
The nail may also be partially or completely avulsed from the nail fold. Nail plate avulsion is almost invariably accompanied by significant nail bed laceration that requires repair. Fractures of the distal phalanx are present in 50% of nailbed injuries.[12]
Most injuries of the nailbed are due to crushing injuries, such as with a hammer.[1] Twenty-five percent of nailbed injuries involve the finger being crushed in a doorway, most commonly car doors. Crush injuries squeeze the soft tissue of the nailbed between the nail and the distal phalanx. This may result in a simple subungual hematoma or a simple or stellate laceration. Saws, knives, drills, moving belts, and lawnmowers are also common causes of nailbed injuries.
Depending on the extent of injury, radiologic evaluation with anteroposterior, lateral, and oblique views of the injured finger(s) may be useful to rule out foreign bodies and fractures or dislocations of the distal finger.[6]
In a study of children with nailbed injuries, the authors found that 50% of their patients had an associated distal phalangeal fracture, most often a comminuted tuft fracture.[13] Most tuft fractures, in the setting of a nailbed injury, require no specific treatment outside of addressing the nailbed injury and protective splinting. Transverse shaft fractures that are significantly displaced may require surgical repair.[14]
In a study utilizing point-of-care ultrasound in patients presenting to the ED with distal finger trauma, sensitivity was 93.4% and specificity was 100% for diagnosing nail bed injury.[15]
Small (less than 25% of the nailbed) and painless subungual hematomas require no intervention, as the hematoma will eventually reabsorb. If the subungual hematoma covers more than 25% of the nailbed or is causing pain, the patient should be offered evacuation via trephination or nail removal (see Hand, Subungual Hematoma Drainage).
Treatment of subungual hematomas covering greater than 25-50% of the nail bed is controversial and varies with personal preference.[16] Historically treatment includes removal of the nail and repair of any underlying lacerations. This practice came about because 50% of these hematomas have concurrent nailbed lacerations. The incidence of nailbed laceration increases to 94% when associated with a distal phalangeal fracture, regardless of the size of the hematoma.[4, 17, 18, 19, 20]
More recent studies have concluded that as long as the nail is still partially adherent to the nailbed or paronychia and is not displaced out of the nail fold, removal of the nail and repair of the nailbed does not improve outcomes versus simple trephination. Neither the size of the hematoma nor the presence of an associated fracture has been associated with adverse outcomes.[13, 21, 22] Trephination is contraindicated if a fracture requires surgical repair or if the germinal matrix is entrapped within the fracture, as delayed union or the formation of an intraosseous inclusion cyst may occur.[14]
The advantages of simple trephination include less pain for the patient, shorter length of stay, and less costly intervention.[13]
Various methods of trephination exist (shown in the image below). The easiest and safest is to use an electric cautery, which melts a hole through the nail. Once the cautery encounters the underlying hematoma, the tip cools, preventing further injury to the nailbed. If the hole is of adequate size, blood will drain and relieve some pain and the pressure sensation for the patient.
View Image | Trephination of a subungual hematoma. |
A paper clip may also be used after it is heated until red hot.[23]
An 18-gauge needle may be used by twirling the needle back and forth with slight downward pressure until dark blood return is noted. Use of an 18-gauge needle is less optimal because of the risk of injury to the nailbed once the nail has been penetrated. Alternatively, the needle may be directed at an oblique angle (45-60°) without applying pressure.[24]
Another technique is use of a sterile 29-gauge extra-fine insulin syringe needle.[25] Instead of penetrating the nail, the needle is inserted at the hyponychium parallel to the nail, aimed at the most distal portion of the hematoma. Care is taken to keep the needle closer to the nail versus the nail bed. Once the hematoma is penetrated, the needle may be withdrawn and light pressure placed on the nail will help with evacuation of the hematoma. This technique may obviate the need for digital block anesthesia, and also may be favorable in evacuating hematomas of the smaller toe nailbeds, where trephination is more difficult.
The use of a 2- or 3-mm biopsy punch has also been described.[26, 27] The biopsy punch is gently twirled back and forth with minimal pressure over the hematoma.
Principles of treatment include minimal debridement, preservation of as much tissue as possible, atraumatic wound care, and splinting with the nail or an alternative material. Nailbed repair is shown in the image below.
View Image | Nailbed repair. |
A digital block of 1% lidocaine hydrochloride without epinephrine provides anesthesia of sufficient duration for most repairs. Bupivacaine extends anesthesia time 4-8 hours for longer procedures.
Children may require procedural sedation and analgesia.
The hand should be prepared with povidone-iodine (Betadine) and covered with sterile drapes. The injured finger should be exsanguinated with a half-inch or 1-inch Penrose drain wrapped in a distal to proximal direction and placed around the base to serve as a tourniquet and provide a blood-free field.
The nail is elevated using the blades of either fine or curved iris scissors or small elevator scissors. Specific care is necessary to not injure the nailbed. A blunt dissecting technique should be used, and the scissors are placed gently underneath the nail until they reach the nail fold. Slowly open the scissors as it is removed. Care must again be taken to avoid further damage to the underlying nailbed or overlying nail fold. Once the nail is sufficiently separated from the nailbed, it is gently removed by applying firm and steady distal traction using a hemostat.
Lacerations to the nailbed should be repaired using 6-0 or smaller absorbable sutures. Minimal to no debridement should be performed because aggressive debridement may cause undue tension on the repair and results in scarring.
When repairing avulsed nails and nailbeds, if the nail is detached proximally, it must be removed to inspect for any damage to the nailbed. Careful inspection of the nail is important because often only a fragment of nailbed may be attached to the undersurface of the avulsed nail. Only outer and dorsal surfaces of the nail should be cleaned. Any large fragments of nailbed should be preserved for use as a free graft. Crushing injuries leave many small pieces of nailbed. If all fragments are not incorporated into the repair, they may grow independently and cause nail horns or spicules. If tissue is not available and the defect is small enough, the area will heal effectively by secondary intention.
Simple dorsal roof lacerations can often be repaired by accurately repairing the skin overlying the nail fold. However, if possible, suturing of the dorsal roof with a 7-0 chromic suture may provide more accurate repair. Associated paronychial injuries must be repaired and stented to prevent pterygium or adhesions, as it serves as a mold to coax nail to grow along a proper path. Distal phalangeal fracture reduction and healing is important to final nail formation. Poor reduction of the bone translates directly into irregularities of the nailbed.
The proximal nail should be reinserted into the nail fold. The replaced nail keeps the nail fold open for new nail growth and provides a protective cover for the nailbed and a precise template for new nail to follow as it regenerates. It also serves as a rigid splint for any underlying fractures and reduces postoperative discomfort and improves postoperative function. Some evidence suggests though that replacing the nail may be unnecessary[28] and may delay wound healing and increase the risk of infection in children.[29]
Before replacement, a small hole should be made in the nail, preferably so that it is not overlying the laceration. This is to allow drainage and thus prevent a growing hematoma to separate the nail from the nailbed.
The nail is then placed back in the nail fold as a stent and held in position by 5-0 or smaller nylon sutures placed by one or a combination of the techniques below:
A hand surgeon should be consulted for significantly avulsed nail matrix or for severe crush injuries.
The prophylactic use of antibiotics is indicated depending on mechanism and extent of injury, such as for crush injuries and human bites or animal bites. Although the benefit of prophylactic antibiotics has not been proven, even if an open fracture of the distal phalanx is present, to be safe many clinicians still prescribe a first-generation cephalosporin when bone or joint is exposed below a nailbed injury. A large, randomized controlled study may be necessary in the future to examine the utility of antibiotics in such circumstances.
Small (less than 25% of the nailbed) and painless subungual hematomas require no intervention, as the hematoma will eventually reabsorb. If the subungual hematoma covers more than 25% of the nailbed or is causing pain, the patient should be offered evacuation via trephination or nail removal (see Hand, Subungual Hematoma Drainage).
Treatment of subungual hematomas covering greater than 25-50% of the nail bed is controversial and varies with personal preference.[4, 17, 18, 19, 20, 16]
More recent studies have concluded that as long as the nail is still partially adherent to the nailbed or paronychia and is not displaced out of the nail fold, removal of the nail and repair of the nailbed do not improve outcomes versus simple trephination. Neither the size of the hematoma nor the presence of an associated fracture has been associated with adverse outcomes.[13, 21, 22] Trephination is contraindicated if a fracture requires surgical repair or if the germinal matrix is entrapped within the fracture, as delayed union or the formation of an intraosseous inclusion cyst may occur.[14]
Lacerations to the nailbed should be repaired using 6-0 or smaller absorbable sutures. Minimal to no debridement should be performed because aggressive debridement may cause undue tension on the repair and results in scarring. Tissue adhesives are also a less invasive option for nailbed and nail repair.[34]
When repairing avulsed nails and nailbeds, if the nail is detached proximally, it must be removed to inspect for any damage to the nailbed.
A new prospective surgical approach has been discussed for large-area defects of the nail bed with distal phalanx exposure, which is a cross finger fascial flap combined with thin split-thickness toe nail bed graft.[42]
Complications of nailbed injuries may include the following:
In general, except for a simple subungual hematoma in which the nailbed was not inspected for potential laceration or injury, a wound check in 2-5 days is suggested to check for infection and to repack the nail fold, if necessary.
Sutures should be removed from any replaced nail in approximately 2-3 weeks.
If acrylic nail, hypodermic syringe sheath, or other material was used as a stent, it should be removed in 3 weeks.
If the original nail was used as a splint, it will be pushed out as new nail grows in, and it will fall out on its own.
The goal of pharmacotherapy is to reduce pain and to prevent infection. If not updated, tetanus immunization is indicated.
Clinical Context: First-generation cephalosporin that inhibits bacterial growth by inhibiting bacterial cell wall synthesis. Bactericidal and effective against rapidly growing organisms forming cell walls. Acceptable alternative to penicillin and may be useful in patients with minor penicillin allergies.
Therapy must cover all likely pathogens in the context of the clinical setting. The prophylactic use of antibiotics is indicated depending on mechanism and extent of injury, such as for crush injuries and human or animal bites. Although the benefit of prophylactic antibiotics has not been proven, even if an open fracture of the distal phalanx is present, to be safe many clinicians still prescribe a first-generation cephalosporin when bone or joint are exposed below a nailbed injury. A large, randomized controlled study may be necessary in the future to examine the utility of antibiotics in such circumstances.
Clinical Context: Usually DOC for treatment of mild to moderate pain if no contraindications exist. Decreases inflammatory reactions and pain by inhibiting the activity of the enzyme cyclooxygenase, resulting in diminished prostaglandin synthesis.
Clinical Context: Has analgesic, antipyretic, and anti-inflammatory effects. Decreases inflammatory reactions and pain by inhibiting the activity of the enzyme cyclooxygenase, resulting in diminished prostaglandin synthesis.
Clinical Context: Used for relief of mild to moderate pain and inflammation. For patients with a small body size, elderly persons, and those with renal or liver disease, initially administer small dosages. Doses >75 mg do not increase therapeutic effects. Administer high doses with caution and closely observe patients' responses.
Clinical Context: Used for relief of mild to moderate pain. Decreases inflammatory reactions and pain by inhibiting the activity of the enzyme cyclooxygenase, resulting in diminished prostaglandin synthesis.
NSAIDs are commonly used for relief of mild to moderate pain. Effects of NSAIDs in treating pain tend to be patient specific, but ibuprofen is usually the drug of choice (DOC) for initial therapy. Other options include ketoprofen, flurbiprofen, and naproxen.
Clinical Context: DOC for pain in patients with documented hypersensitivity to aspirin or NSAIDs, with upper GI disease, or who are taking oral anticoagulants.
Clinical Context: Drug combination indicated for treatment of mild to moderate pain.
Clinical Context: Drug combination indicated for the relief of moderate to severe pain.
Clinical Context: Drug combination indicated for the relief of moderate to severe pain. DOC for aspirin-hypersensitive patients.
These agents are reserved for those with moderate to severe pain. They should be prescribed in the setting of those who have contraindications to NSAIDS, or for breakthrough pain while using NSAIDS. Current practice dictates a short course of use.
Clinical Context: Used to induce active immunity against tetanus in selected patients. The immunizing agent of choice for most adults and children aged > 7 y are tetanus and diphtheria toxoids. Necessary to administer booster doses to maintain tetanus immunity throughout life. Pregnant patients should receive only tetanus toxoid, not a diphtheria antigen-containing product. May administer into deltoid or midlateral thigh muscles in children and adults. In infants, preferred site of administration is the mid thigh laterally.
This agent is used for tetanus immunization. Administer booster injection in previously immunized individuals to prevent this potentially lethal syndrome.
Clinical Context: Used for passive immunization of persons with wounds that may be contaminated with tetanus spores.
Patients who may not have been immunized against Clostridium tetani products should receive tetanus immune globulin (Hyper-Tet).