Bottom Line Up Top: Replacing the nail into the eponychial fold doesn’t appear to be critical to nail regrowth and cosmetic outcomes of finger injuries with nail avulsion.
Clinical Scenario: A 6-year-old boy presents to the Peds ED with an injury to their left 2nd digit. The finger was caught in a car door, injuring the nail and nail bed. On presentation, the patient has a linear laceration the full length of the nailbed and the nail has been avulsed. You provide ketamine for procedural sedation, block, irrigate and repair the nail bed laceration. Before replacing the nail into the eponychial fold, the patient wakes from sedation. You consider whether you should re-sedate the patient to replace the nail as you are concerned about the cosmetic outcome of the repair.
What Your Gut Says: Do whatever you have to do to replace the nail. If the eponychial fold isn’t stented open, the fingernail won’t regrow and the patient will have a poor cosmetic outcome.
What The Evidence Says: Historically, nail bed lacerations with nail avulsion have been managed with primary repair of the nail bed and replacement of the nail (or alternate synthetic material) into the eponychial fold. Replacement allows the nail to act as a rigid splint, reduce pain to the injured site and prevent adhesions between the eponychial fold and germinal matrix (Patel 2014). Classic teaching argues that failure to replace the nail will prevent or alter new nail growth leading to cosmetic deformity. Nail replacement can be technically difficult or inhibited by patient discomfort. Additionally, the replaced nail often becomes dislodged after discharge from the ED necessitating revisit. Recent literature, however, calls the classic teaching into question.
The NINJA trial, performed in 2023, randomized ~ 450 children with nail bed injuries to primary repair with nail/substitute replacement versus no replacement. The primary outcomes of interest were infection at 7 days and cosmetic outcome at 4 months. The authors found no statistically significant difference in infections and no difference in cosmetic outcomes between the two groups (Jain 2023). Additionally, there were no differences in the secondary outcomes of pain, patient satisfaction or delayed infections. Interestingly, healthcare costs were higher in the nail replacement group. It’s hard to make strong recommendations based on a single study and though not shown here, the nail may provide protection, stability and pain control. If it’s simple to replace, it’s probably fine to do so but, if there are any challenges in replacement, it can be left as is.
Diving into this topic raises an additional question: Is there benefit to removing a nail to repair an underlying injury? Once again, there is dogmatic teaching which recommends nail removal if the patient has > 50% subungual hematoma. Performance of nail removal, repair and replacement is both invasive and time consuming. Though there aren’t large trials, the existing evidence supports conservative management (i.e. leaving the nail in place and just trephinating for drainage) (Seaberg 1991, Roser 1999, Batrick 2003, Dean 2012).
Bottom Line: Despite the classic teaching, the best available evidence doesn’t show a cosmetic difference between replacing the nail and not replacing the nail in pediatric patients. You would be well supported by the data if you chose to skip nail replacement.
Additional Resources
EMRAP UC Max: The Nail Bed Injury
First10EM: The NINJA Trial: Do you replace the fingernail after nail bed repair?
References
Patel L. Management of simple nail bed lacerations and subungal hematomas in the emergency department. Pediatr Emer Care 2014; 30: 742-8. PMID: 25275357
Jain A et al. Effectiveness of nail bed repair in children with or without replacing the fingernail: NINJA multicentre randomized clinical trial. Br J Surg. 2023;110(4):432-438 PMID: 36946338
Seaberg DC, Angelos WJ, Paris PM. Treatment of subungual hematomas with nail trephination: a prospective study. Am J Emerg Med. 1991 May;9(3):209-10. PMID: 2018587
Roser SE, Gellman H. Comparison of nail bed repair versus nail trephination for subungual hematomas in children. J Hand Surg Am. 1999 Nov;24(6):1166-70. PMID: 10584937
Batrick N, Hashemi K, Freij R. Treatment of uncomplicated subungual haematoma. Emerg Med J. 2003 Jan;20(1):65. PMID: 12533376
Dean B, Becker G, Little C. The management of the acute traumatic subungual haematoma: a systematic review. Hand Surg. 2012;17(1):151-4. PMID: 22351556
