Fingernail injuries

From Medical-Wiki

Nailbed and fingertip injuries are exceedingly common because they are involved in most of a person’s daily activities. The fingertip is also a crucial element in those activities, making appropriate treatment of its injury an important part of primary and emergency care.

Contents 1 Recovery process 2 Treatment 2.1 Healing by secondary intention 2.2 Healing by primary closure 3 Subungual hematoma 4 Nailbed lacerations 5 Mallet finger 6 Jersey finger

Recovery process

The anatomy of the fingertip is complex. [1] The germinal matrix produces the vast majority of a nail’s volume. Following injury, a period of between 70 and 160 days will be required to regain its longitudinal length. Growth will be stunted or absent for about 3 weeks. For about 4 weeks, there will be accelerated growth. Then growth returns to normal. These differences in growth rates are what create the lump in nails that regrow following trauma.

If the perionychium is scarred, there will be a defect in new nail growth. A scar of the germinal matrix will leave a nail split or absent. A scar to the dorsal roof will create a dull streak. A scar to the sterile matrix will result in a split or nonadherent nail distal to the scar. [2]

Treatment

A variety of factors including the patient’s age and sex, occupation and hobbies, and nature of the injury dictate the approach to treatment. A piano teacher’s injury must be approached differently than that of a manual laborer. A child should be treated differently than a 70 year-old with a Dupuytren’s contracture. Bone or tendon exposure contraindicates certain treatment options. [3]

The two primary means of treating fingertip injuries are healing by secondary intention via open technique and primary closure with revision amputation if needed.

Healing by secondary intention

Healing by secondary intention may be used when there is no protruding bone. If there is minimal protrusion of bone, open closure may be used after debriding the bone with a rongeur. Wounds greater than 1 cm take longer than a month to heal and may thus be unsuitable for open technique. Open treatment is quite suitable for children because of their greater capacity for tissue regeneration.

Healing by primary closure

Primary closure can often be completed by recruiting adjacent tissue. This will sometimes require bone shortening. However, if there is involvement of the distal tuft of the extensor tendon, consultation from a hand surgeon may be judicious.

There are a variety of flaps that are available for closing more extensive injuries. These are obviously the purview of orthopedic surgeons or hand surgeons. [4]

Subungual hematoma

A subungual hematoma develops when blood is pooled beneath the nail. The subsequent pressure can be exceedingly painful. Evacuation of the hematoma should be completed through the use of a hand held cautery unit or a heated paper clip. 2 or 3 small holes should be burned in the nail to allow drainage. The nail should then be protectively splinted for a few days.

Nailbed lacerations

In general, nailbed lacerations require removal of the nail and suturing of the nailbed to assure a smooth matrix. These lacerations are usually the result of high velocity crush injuries. Radiographs should be performed to assess the possibility of tuft fractures or foreign bodies.

Mallet finger

Damage to the extensor mechanism produces what is called a “mallet finger.” If only the tendon is involved, the injury is called a tendinous mallet. If there is also an avulsion fracture, the injury is termed a bony mallet. Most mallet injuries may be treated nonoperatively, but those with extensive avulsions or sublexation of the distal phalanx should be referred.

Jersey finger

The so-called jersey finger (so named because it occurs when a football player grabs another’s jersey while trying to make a tackle) occurs when there is avulsion of the flexor digitorum profundus (FDP). Since this injury requires surgical repair, diagnosis of this injury is important and often missed. The digit typically appears swollen and tender along the volar surface of the DIPJ. With the finger extended so that the FDP is isolated, DIJP flexion is absent. (Flexion at proximal joints is possible because of the action of flexor digitorum superficialis and lumbrical muscles.) [5]