Orthopaedic Surgery - Subungual Hematoma

Basics

A subungual hematoma is a:

Collection of blood beneath the nail plate

and above the:

Nail bed

of a finger or toe.

It usually follows:

Blunt trauma

that injures the underlying nail-bed soft tissues while the nail plate remains:

Intact or largely intact.

Pain Mechanism

Blood trapped beneath the rigid nail plate creates:

Pressure

against the sensitive:

Nail bed and distal phalanx.

This can produce:

Severe throbbing pain.

Nail-Bed Injury Patterns

Underlying nail-bed injury may consist of:

Simple linear laceration

Stellate laceration

or

Crush injury.

Epidemiology

Subungual hematoma is one of the most common:

Distal digit injuries

seen in:

Emergency departments

and

Outpatient practice.

Age

The injury commonly affects:

Older children

Adolescents

and

Young adults

although it can occur at:

Any age.

Most Commonly Injured Digit

The:

Middle finger

is commonly injured because it projects farther than the adjacent digits and is frequently exposed to:

Crush trauma.

Etiology

The usual cause is:

Blunt trauma to the distal phalanx.

Common Mechanisms

Typical mechanisms include:

Finger caught in a door

Crushing between two objects

Impact from a heavy object

and injuries involving:

Tools or machinery.

Associated Conditions

The most important associated injury is:

Distal phalanx fracture.

Nail-bed laceration may also coexist with:

Crush injury

or

Open fracture.

Diagnosis

Diagnosis is usually based on:

History

and

Physical examination.

Signs and Symptoms

Patients typically present shortly after injury with:

Localized distal finger or toe pain

and a clear history of:

Trauma.

Pain

Pain is often:

Throbbing

and may be disproportionately severe because of:

Pressure beneath the nail plate.

Visible Hematoma

Inspection reveals a:

Dark red

Purple

or

Black discoloration

visible beneath the:

Nail plate.

Nail Deformity

A nail deformity is usually a:

Late finding

and may indicate a previously unrecognized:

Nail-bed injury

or disruption of the:

Nail matrix.

Physical Examination

The examination should evaluate:

Nail integrity

Nail-fold disruption

Extent of hematoma

Tenderness

Swelling

and

Neurovascular status.

Nail Plate

Determine whether the nail plate is:

Intact

Split

Displaced

or detached from the:

Nail folds.

Nail Folds

Inspect the:

Eponychial fold

and

Lateral nail folds

for:

Laceration

or disruption.

Distal Phalanx

Diffuse swelling and marked bony tenderness raise concern for:

Associated distal phalanx fracture.

Neurovascular Examination

Document:

Sensation

Capillary refill

and distal:

Perfusion.

Imaging

Plain Radiographs

Radiographs should be considered when there is concern for:

Distal phalanx fracture

based on mechanism, tenderness, deformity, or substantial crush injury.

Recommended Views

Typical imaging includes:

AP

Lateral

and

Oblique views

of the affected digit.

Differential Diagnosis

Important alternatives include:

Distal phalanx contusion

Distal phalanx fracture without subungual bleeding

Subungual melanoma

and

Pyogenic granuloma.

Subungual Melanoma

A dark lesion under the nail without a convincing history of:

Trauma

or one that persists and evolves should raise concern for:

Melanocytic pathology.

Pyogenic Granuloma

A pyogenic granuloma may develop near the:

Nail fold

and can bleed easily.

It may follow:

Minor penetrating trauma

or manipulation of the:

Cuticle.

Treatment

Management depends on:

Pain

Nail integrity

Associated fracture

and evidence of:

Nail-bed disruption.

General Measures

A painful acute subungual hematoma beneath an intact nail can usually be treated with:

Trephination.

The purpose is to:

Decompress the hematoma

and rapidly reduce:

Pain.

Trephination

Trephination creates one or more small openings in the:

Nail plate

allowing trapped blood to:

Drain.

Modern Size Considerations

Historically, hematomas involving more than approximately:

50% of the nail surface

were treated with nail removal and nail-bed repair.

Modern practice is less dependent on:

Hematoma size alone.

If the nail plate and nail folds are intact and there is no displaced fracture or obvious nail-bed disruption, even a:

Large hematoma

may often be managed successfully with:

Simple trephination.

Indications for Trephination

Trephination is most useful when the hematoma is:

Acute

Painful

and the nail plate remains:

Intact.

Timing

Trephination is most effective during the:

First 24–48 hours

before the blood becomes extensively:

Clotted.

Preparation

The digit and nail should be cleaned using:

Sterile or clean antiseptic technique.

Anesthesia

A digital nerve block is usually:

Not required

for uncomplicated trephination because the nail plate itself is:

Insensitive.

Trephination Methods

The nail may be decompressed using:

Electrocautery

or a carefully rotated:

Large-bore needle.

Electrocautery

A battery-powered cautery device can rapidly create a hole through the:

Nail plate.

The operator stops as soon as blood begins to:

Drain.

Needle Technique

A needle may be rotated gently through the nail plate until the:

Hematoma cavity

is reached.

Care should be taken to avoid injuring the underlying:

Nail bed.

Number of Holes

Usually:

One or two openings

are sufficient for drainage.

Additional openings may be created if drainage remains:

Incomplete.

Pain Relief

Successful decompression typically produces:

Rapid and substantial pain relief.

When Nail Removal Is Appropriate

Nail removal and direct nail-bed inspection may be indicated when there is:

Nail avulsion

Nail-fold disruption

Major nail-plate laceration

Displaced distal phalanx fracture

or obvious:

Nail-bed injury requiring repair.

Associated Fracture

A nondisplaced distal phalanx fracture may be treated with:

Protective splinting

in addition to management of the:

Nail injury.

Displaced Fracture

A displaced fracture may require:

Reduction

and occasionally:

Operative fixation.

Activity

Activity may continue:

As tolerated

provided the injured digit is adequately:

Protected.

Protective Splinting

Patients with associated fracture or substantial fingertip tenderness may benefit from a:

Tip protector

or

Distal phalanx splint.

Physical Therapy

Formal therapy is rarely needed for an uncomplicated:

Subungual hematoma.

Hand Therapy

A hand therapist may provide a custom:

Fingertip protector

when hypersensitivity interferes with:

Work or activity.

Medication

Pain control may include:

Acetaminophen

or

NSAIDs

when medically appropriate.

Antibiotics

Routine prophylactic antibiotics are generally:

Not necessary

after uncomplicated trephination or a clean closed injury.

They may be considered when there is:

Open contamination

Significant soft-tissue injury

or another specific infection-related indication.

Nail-Bed Repair

When a significant nail-bed laceration requires repair, the nail plate may need to be:

Removed.

Anesthesia for Repair

A:

Digital nerve block

provides adequate regional anesthesia for most:

Nail-bed repairs.

Nail Removal

The distal nail edge is gently elevated and separated from the:

Nail bed

and

Eponychial fold

while minimizing additional:

Tissue trauma.

Irrigation

The wound should be thoroughly:

Irrigated

before repair.

Nail-Bed Suturing

Nail-bed lacerations are typically repaired using:

Fine absorbable sutures

such as approximately:

6-0 or 7-0 material.

Nail-Fold Splinting

After nail removal, maintaining the space beneath the:

Proximal nail fold

can help prevent adhesions and later:

Nail deformity.

Nail Replacement

The original nail plate may sometimes be replaced as a:

Biologic splint

if sufficiently intact.

Alternative Splint

If the native nail cannot be used, an appropriate sterile substitute may be placed beneath the:

Eponychial fold.

Dressing

The nail bed should be covered with a:

Nonadherent dressing

followed by protective:

Gauze or fingertip dressing.

Follow-Up

Follow-up depends on the:

Severity of injury.

After Simple Trephination

Patients treated by trephination alone often require only:

As-needed follow-up

if symptoms rapidly improve.

After Nail-Bed Repair

Patients undergoing nail-bed repair should generally be reviewed within approximately:

1 week.

Wound Care

Patients should keep the digit:

Clean

and monitor for:

Increasing redness

Drainage

Swelling

or

Fever.

Prognosis

The prognosis is generally:

Excellent

when associated nail-bed and bony injuries are identified and treated appropriately.

Nail Regrowth

A fingernail may require several:

Months

to grow completely.

Toenails generally take:

Longer.

Complications

Nail Deformity

Damage to the nail bed or matrix may lead to:

Ridging

Fissuring

Splitting

or abnormal:

Nail growth.

Eponychial Adhesions

Failure to preserve the space beneath the:

Eponychial fold

after nail removal may result in:

Adhesion formation

and subsequent:

Nail deformity.

Split Nail

A poorly healed nail-bed laceration may cause a:

Split nail

or a nail that does not adhere normally to the:

Nail bed.

Infection

Infection is uncommon with proper:

Wound care.

However, contaminated injuries or improper drainage can occasionally lead to:

Soft-tissue infection

or

Osteomyelitis.

Persistent Pain

Persistent pain after decompression should raise concern for:

Associated fracture

Incomplete drainage

or another:

Underlying injury.

Patient Monitoring

Patients should be monitored for:

Pain relief

Wound healing

Infection

and normal:

Nail regrowth.

Key Principle

A subungual hematoma is a collection of blood beneath the nail plate following trauma to the nail bed, often producing:

Severe throbbing pain from pressure within the confined nail space.

For an acute painful hematoma with an intact nail and nail folds, treatment usually consists of:

Simple nail trephination, which provides rapid decompression and pain relief.

The historical rule that hematomas involving more than:

50% of the nail

require nail removal is no longer applied rigidly; management depends more on:

Nail integrity, nail-fold injury, associated fracture, and evidence of significant nail-bed disruption.

Nail removal and repair are reserved for injuries with:

Avulsion, major nail disruption, displaced fracture, or a clearly repairable nail-bed laceration.

The overall prognosis is:

Excellent, although inadequately treated nail-bed injuries may lead to:

Permanent nail deformity.