What is the appropriate management of a suspected nail‑bed injury?

Management of Nail Bed Injury

Remove the nail plate, directly visualize and meticulously repair the nail bed laceration with absorbable sutures, then replace the nail plate as a biological dressing to prevent adhesions and nail deformities.

Initial Assessment and Diagnosis

When evaluating a suspected nail bed injury, you must look for specific clinical indicators that determine management:

• Subungual hematoma involving >25-50% of the nail surface strongly suggests underlying nail bed laceration requiring exploration 1, 2
• Visible nail plate disruption or avulsion indicates definite nail bed injury needing direct repair 3, 4
• Associated distal phalanx fracture (present in many cases) predicts higher complication rates and necessitates more aggressive management 3
• Mechanism of injury matters: door crush injuries account for 59.5% of pediatric cases and carry higher infection risk 3

Obtain plain radiographs to identify distal phalanx fractures, which are present in a substantial proportion of nail bed injuries and predict complications 1, 3.

Treatment Algorithm

For Subungual Hematoma

• If hematoma <25% of nail surface and nail plate intact: Simple trephination (drilling through nail plate) provides adequate drainage and pain relief 5, 2
• If hematoma >50% of nail surface: Remove the nail plate to inspect for underlying nail bed laceration, as the hematoma size correlates with laceration severity 2

For Confirmed Nail Bed Laceration

The critical steps are:

1. Remove the nail plate completely using blunt dissection to expose the entire nail bed 1, 2
2. Irrigate thoroughly with saline without additives (per trauma guidelines for open wounds) 6
3. Repair the nail bed meticulously with fine absorbable sutures (6-0 or 7-0) to restore anatomic alignment 3, 2
4. Replace the original nail plate as a biological splint between the nail fold and nail bed to prevent adhesions 2
   • If the original nail is too damaged, use a substitute material
5. Reduce any associated distal phalanx fracture during the same procedure 1

Antibiotic Prophylaxis

Administer systemic antibiotics when:

• Distal phalanx fracture is present (making this an open fracture) 6, 3
• Mechanism involves door crush, sports injury, or road traffic accident 3
• Use cefazolin or clindamycin as first-line prophylaxis per AAOS guidelines for open extremity trauma 6

Timing Considerations

Perform definitive repair as soon as reasonable, ideally within 24 hours of injury 6. Delayed or inadequate treatment substantially increases the risk of permanent nail deformities including split nail, hook nail, and nonadherence of the nail plate 1, 3.

Critical Pitfalls to Avoid

• Do not assume a large subungual hematoma can be managed with trephination alone - blunt trauma easily causes more extensive nail bed laceration than anticipated on initial examination 1
• Do not underestimate the injury based on external appearance - the nail plate often masks significant underlying nail bed disruption 1, 4
• Do not skip nail plate removal when indicated - attempting to repair through a small opening leads to inadequate visualization and poor outcomes 2
• Stellate lacerations and severe crush injuries are the strongest predictors of complications and require especially meticulous repair 3

Expected Outcomes and Complications

With proper initial assessment and meticulous repair, most nail bed injuries heal well with few complications 3. However, inadequate initial treatment often necessitates secondary reconstruction, which gives unpredictable results 1.

Common complications when repair is suboptimal include:

• Fingertip sensitivity changes (5.3%) 3
• Split nail deformity (5.3%) 3
• Infection (3.9%) 3
• Nail plate nonadherence (2%) 3
• Hook nail deformity (1%) 3

The presence of distal phalanx fracture and injury type (stellate or severe crush) are the strongest predictors of complications 3.