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Hand, Subungual Hematoma Drainage

Oliver Mayorga, MD, Staff Physician, Department of Emergency Medicine, Lawrence and Memorial Hospital
Stephen P Wall, MD, MS, Assistant Professor, Department of Emergency Medicine, Epidemiology and Population Health, Jacobi Medical Center, Albert Einstein College of Medicine

Updated: Oct 22, 2009

Introduction

Subungual hematomas are common nail bed injuries caused by blunt or sharp trauma to the fingers or toes.1 Bleeding from the rich vascular nail bed results in increased pressure under the nail and can cause significant discomfort.2 Subungual hematoma drainage, also known as nail bed trephination, can be performed to relieve this discomfort.3

For information on various nail pathologies, see eMedicine article Nail Pathology.

Anatomy

The perionychium is the tissue on each side of the nail, and the eponychium is the skin immediately proximal to the nail. Beneath the eponychium lies the germinal matrix; its distal portion, or lunula, is visible under the proximal nail. The germinal matrix generates most of the nail, while the more distal sterile matrix adheres the nail to the nail bed and assists with nail migration. Injury to the germinal matrix may lead to permanent nail loss.4,5

Nail bed anatomy figure 1.

Nail bed anatomy figure 1.



Nail bed anatomy figure 2.

Nail bed anatomy figure 2.


Indications

  • The presence of a painful subungual hematoma with the nail edges intact4

Contraindications

  • If nail removal is indicated to explore for complex nail bed lacerations (eg, if nail edges are disrupted with a deep laceration), subungual hematoma drainage is not indicated. Most simple nail bed lacerations, however, do not require nail removal and laceration repair.
  • Subungual hematoma drainage is not necessary if the hematoma is not painful.
  • In the presence of acrylic nails, electrocautery is contraindicated until the acrylic nail is removed. (Acrylic nails may be flammable, which is of concern if an electrocautery tool is used.6 )
  • Of note, previous sources have recommended nail bed trephination only for subungual hematomas smaller than 25-50% of the nail surface. Recent studies have shown that hematoma size or the presence of underlying distal phalanx fractures do not result in a difference in complications. Therefore, nail bed trephination may be indicated for hematomas of any size if the nail edges are not disrupted.7,8,9

Anesthesia

  • Subungual hematoma drainage does not usually require routine anesthesia.
  • A digital block may be considered. For more information, see Local Anesthesia and Regional Nerve Block Anesthesia.

Equipment

  • Options for the tool for nail penetration include the following:
    • Needle, 18 gauge (ga)
    • Electrocautery tool

      Cautery tool.

      Cautery tool.


    • Paper clip and sterilizing flame
  • Povidone-iodine solution (Betadine)
  • Nonsterile gloves
  • Gauze
  • Topical antibiotic (eg, bacitracin)
  • Finger splint (optional)

Equipment.

Equipment.


Positioning

  • The patient should be resting with the finger in a position of comfort on a supportive surface.

    Positioning of finger.

    Positioning of finger.


  • The clinician should sit in a position of comfort on the side of the injury.

Technique

  • Prepare the finger with Betadine.

    Preparation of finger.

    Video available at http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-79936-82926-141706.flv.


  • Using the preferred tool for nail penetration, make a hole at the base of the nail or in the center of the hematoma. This hole must be large enough for the hematoma to drain.
    • If using an 18-ga needle, twirl the needle between the thumb and index finger with slight downward pressure until no resistance is felt and dark blood return is seen from the hole.

      Trephination with needle.

      Video available at http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-79936-82926-149101.flv.


    • If using a paper clip, first heat the end of the paper clip in open flame to sterilize it. Apply the hot tip to the nail until resistance is no longer felt and blood return is seen.
    • If using a sterile cautery tool, activate cautery until the tip is hot. Apply the tool to the nail as with a heated paper clip.
  • Allow the hematoma to drain. Gentle squeezing at the tip of the finger may facilitate hematoma drainage.
  • Apply antibacterial ointment (eg, bacitracin) over the trephination site and dress the wound with gauze or an adhesive bandage.

    Posttrephination care.

    Video available at http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-79936-82926-149104.flv.


  • Apply a finger splint for additional comfort.
  • Instruct patient to avoid soaking the finger and to keep the finger dry for 2 days.

Pearls

  • When appropriate, take a radiograph of the finger to rule out an underlying fracture that may require splinting.
  • Always check for the presence of an associated extensor tendon injury.
  • Hematomas that are larger than 50% of the nail do not necessarily require nail removal and exploration.
  • The nail may fall off during the week following hematoma drainage but should regrow as long as the germinal matrix is intact.10
  • Multiple holes may be necessary to facilitate adequate drainage.
  • Drainage of the subungual hematoma does not accelerate healing or prevent infection.
  • If the heat of an electrocautery device is painful for the patient (which is not typical), an 18-ga needle should instead be used for trephination.

Complications

  • Injury to the nail bed can result if the nail penetration tool is advanced too deep.11
  • Infection may occur if bacteria are introduced into the trephination site during the procedure.
  • Ineffective drainage may result if the trephination hole is not large enough.

Multimedia

Equipment.

Media file 1: Equipment.

Positioning of finger.

Media file 2: Positioning of finger.

Cautery tool.

Media file 3: Cautery tool.

Nail bed anatomy figure 1.

Media file 4: Nail bed anatomy figure 1.

Nail bed anatomy figure 2.

Media file 5: Nail bed anatomy figure 2.

Media file 6: Preparation of finger.

Video available at http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-79936-82926-141706.flv.

Media file 7: Trephination with needle.

Video available at http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-79936-82926-149101.flv.

Media file 8: Posttrephination care.

Video available at http://img.medscape.com/pi/emed/ckb/clinical_procedures/79926-79936-82926-149104.flv.

References

  1. Hart RG, Kleinert HE. Fingertip and nail bed injuries. Emerg Med Clin North Am. Aug 1993;11(3):755-65. [Medline].

  2. Huang YH, Ohara K. Medical pearl: subungual hematoma: a simple and quick method for diagnosis. J Am Acad Dermatol. May 2006;54(5):877-8. [Medline].

  3. Salter SA, Ciocon DH, Gowrishankar TR, Kimball AB. Controlled nail trephination for subungual hematoma. Am J Emerg Med. Nov 2006;24(7):875-7. [Medline].

  4. Brown RE. Acute nail bed injuries. Hand Clin. Nov 2002;18(4):561-75. [Medline].

  5. Green D, Hotchkiss R, Pederson W, Wolfe S. The Perionychium. In: Green's Operative Hand Surgery. 5th ed. Philadelphia, Pa: Elsevier; 2005:389-416.

  6. Gamston J. Subungual haematomas. Emerg Nurse. Nov 2006;14(7):26-34. [Medline].

  7. Roser SE, Gellman H. Comparison of nail bed repair versus nail trephination for subungual hematomas in children. J Hand Surg [Am]. Nov 1999;24(6):1166-70. [Medline].

  8. Seaberg DC, Angelos WJ, Paris PM. Treatment of subungual hematomas with nail trephination: a prospective study. Am J Emerg Med. May 1991;9(3):209-10. [Medline].

  9. Hart R, Uehara D, Wagner MJ. Emergency and Primary Care of the Hand. Dallas, Tex: American College of Emergency Physicians; 2001:191-200.

  10. Cohen PR, Schulze KE, Nelson BR. Subungual hematoma. Dermatol Nurs. Feb 2007;19(1):83-4. [Medline].

  11. Bonisteel PS. Practice tips. Trephining subungual hematomas. Can Fam Physician. May 2008;54(5):693. [Medline].

  12. Roberts JR, Hedges JR. Clinical Procedures in Emergency Medicine. Vol 1. 3rd ed. Philadelphia, Pa: WB Saunders Company; 1998:656-8.

Keywords

subungual hematoma drainage, nail bed trephination, trephination, nail hematoma drainage, nail bed injury, fingernail injury, nailbed injury, finger injury, subungual hematoma

Contributor Information and Disclosures

Author

Oliver Mayorga, MD, Staff Physician, Department of Emergency Medicine, Lawrence and Memorial Hospital
Oliver Mayorga, MD is a member of the following medical societies: American College of Emergency Physicians and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Coauthor(s)

Stephen P Wall, MD, MS, Assistant Professor, Department of Emergency Medicine, Epidemiology and Population Health, Jacobi Medical Center, Albert Einstein College of Medicine
Stephen P Wall, MD, MS is a member of the following medical societies: Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Chief Editor

Erik D Schraga, MD, Consulting Staff, Department of Emergency Medicine, Mills-Peninsula Emergency Medical Associates; Consulting Staff, Permanente Medical Group, Kaiser Permanente, Santa Clara Medical Center
Disclosure: Nothing to disclose.

Acknowledgments

The authors would like to acknowledge the patients who allowed us to use their images for teaching purposes.

The authors and editors of eMedicine gratefully acknowledge the assistance of Lars Grimm with the literature review and referencing for this article.

For more information

Web Links

National Center for Emergency Medicine Informatics: Subungual Hematoma

Best Evidence Topics: Treatment of uncomplicated subungual haematoma

Best Evidence Topics: Trephination infection risk

Wheeless' Textbook of Orthopaedics Online: Nail Bed Injury/Pathology

Further Reading

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