Nail Bed Repair: How Dermatologists Treat Nail Injuries and Trauma

What Is Nail Bed Repair?

The nail bed is the specialized skin tissue directly beneath your nail plate. It has a unique structure — longitudinal ridges that interlock with the underside of the nail, keeping it firmly attached. When the nail bed is injured (lacerated, crushed, or partially torn away), it must be repaired surgically to create a smooth, intact surface for the new nail to grow on. Without repair, the regrowing nail encounters the irregular scar tissue and grows abnormally — often splitting, ridging, or failing to adhere to the bed.

Nail bed repair involves carefully stitching the torn nail bed tissue back together, removing any blood clots, and replacing the nail plate (or a substitute) as a splint to protect the repair while it heals. The procedure is typically done under digital nerve block (local anesthesia) and takes 30-60 minutes depending on the injury complexity.

Signs That Nail Bed Repair Is Needed

You may need nail bed repair if you have a subungual hematoma (blood under the nail) involving more than 50% of the nail plate — this suggests a significant nail bed laceration beneath, a nail that has been partially or completely torn off (avulsed) by trauma, a crushing injury to the fingertip (e.g., caught in a door, hit with a hammer) with obvious nail deformity, a visible laceration or gap in the nail bed visible after removing a damaged nail, or a distal phalanx (fingertip bone) fracture associated with nail injury — these often accompany nail bed lacerations.

What Causes Nail Bed Injuries?

Nail bed injuries are almost always traumatic in origin: crushing injuries (finger caught in a door — the most common cause, especially in children), direct blows (hammer strikes, dropped objects), lacerations (knife cuts, machinery), avulsion injuries (nail torn off by catching on something), and sports injuries (ball strikes, cleats). Fingernails are injured far more often than toenails, and the middle and ring fingers of the dominant hand are most frequently affected.

Treatment: What Nail Bed Repair Involves

Simple subungual hematoma (small blood collection): If the nail is intact and the hematoma is small (less than 50% of the nail), trephination (making a small hole in the nail plate with a heated needle or drill) drains the blood and relieves pressure. No nail bed repair is needed — the bed is likely intact.

Nail bed laceration repair:

1. Digital nerve block: Complete numbing of the finger or toe.
2. Nail removal: The damaged nail plate is carefully removed to expose the injured nail bed. The nail is saved for later replacement.
3. Wound assessment: The laceration is cleaned, blood clots removed, and the injury pattern assessed.
4. Repair: The nail bed is sutured with very fine absorbable sutures (6-0 or 7-0 chromic gut or Vicryl Rapide) under magnification. Precise alignment of the bed is critical — even 1mm of misalignment can cause a permanent nail ridge.
5. Nail replacement: The original nail plate (cleaned) is placed back over the repaired bed as a biological splint, held in place with a suture through the nail fold. If the original nail is too damaged, a synthetic substitute (silicone sheet or foil) is used. This splint protects the repair and guides proper nail regrowth.
6. Splinting: A finger splint immobilizes the digit for 2-3 weeks.

Recovery: Stitches absorb on their own. The replaced nail plate falls off naturally as the new nail grows in from the matrix (3-6 months). Keep the finger clean, dry, and splinted as instructed. The new nail takes 4-6 months (fingernails) or 12-18 months (toenails) to fully regrow.

Results: With prompt, careful repair, 80-90% of patients achieve a normal or near-normal nail appearance. Results are best when repair is performed within 24 hours of injury. Delayed repair (beyond 7 days) has significantly worse cosmetic outcomes.

When to See a Dermatologist

Seek medical attention promptly (within 24 hours) for any nail injury that involves nail avulsion (partial or complete nail torn off), significant bleeding under the nail (subungual hematoma covering more than 50% of the nail), visible damage to the nail bed, associated fingertip fracture, or a crushing injury with obvious nail deformity. Time matters for nail bed repair — the sooner the repair is performed, the better the long-term result.

Frequently Asked Questions

Will my nail grow back normally after repair?

With proper nail bed repair performed within 24 hours of injury, 80-90% of patients achieve a normal or near-normal nail. Minor irregularities (a slight ridge, mild thinning) are possible and depend on the severity of the original injury. The nail takes 4-6 months to fully regrow for fingernails. During regrowth, the new nail may appear irregular initially but often improves as it grows out to its full length.

Why does my crushed fingernail need to be removed for repair?

The nail plate must be removed to see and repair the injured nail bed underneath. The nail bed laceration is invisible while the nail plate is in place. After repair, the original nail is placed back (as a splint) or a substitute is used — it's not permanently removed. A new nail will grow from the matrix to replace it over 4-6 months.

What happens if I don't get my nail bed repaired?

Without repair, the nail bed laceration heals with scar tissue. The regrowing nail encounters this irregular scar and typically develops a permanent split, ridge, or non-adherent segment. The nail may also grow with an abnormal shape or fail to attach properly to the bed. While not medically dangerous, the deformity is permanent and cannot be corrected later as well as an initial repair would achieve.

Is nail bed repair done under general anesthesia?

No — nail bed repair is almost always performed under digital nerve block (local anesthesia), which completely numbs the finger. General anesthesia is rarely needed for adults. For young children who cannot cooperate with the procedure, sedation or brief general anesthesia may be used. The procedure takes 30-60 minutes.

References

Trusted Resources

• American Academy of Dermatology Association. "Nail Injuries." aad.org
• American Society for Surgery of the Hand. assh.org
• Mayo Clinic. "Broken or Detached Nail." mayoclinic.org

Seek prompt medical attention for nail injuries — early repair within 24 hours gives the best chance of a normal-looking nail.