FAST TRACK: Why Over-Complicate It? A Review of the Hair Apposition Technique

In the appropriate patient, Hair Apposition Technique (HAT) for repair of scalp lacerations is an evidence-based but often forgotten repair technique. This post will review the approach to scalp laceration repair using the HAT.

SUPPLIES REQUIRED

  • Wound cleaning/irrigation supplies 

  • Sterile Gauze sterile? I assume this is just to keep the area dry so likely regular gauze will work

  • Dermabond 

  • 1-2 pairs of forceps and/or Kelly clamps 

  • Optional: pre-treat with LET

HOW-TO

  1. Thoroughly clean/irrigate wound, evaluate for any foreign bodies. Wound should be dry for dermabond to stick well

  2. Isolate a small cluster of hair (~5-10 strands) on one edge of the wound and twist the strands around each other to form a sort of “string”

  3. Repeat with a second cluster of hair (~5-10 strands) on the directly opposed wound edge 

  4. Take the two groups of twisted strands and either twist them around one another 2-3 times or create a single overhand knot, pull tension until wound edges opposed

  5. Maintain tension on the twist/knot and apply a few drops of dermabond over the knot/twist 

  6. Allow tissue adhesive to dry before releasing tension on hair or covering

  7. Don’t forget to verify tetanus status!

Figure 1. Hair Apposition Technique [1]

PATIENT INSTRUCTIONS

  • Avoid washing hair for 2 days, after that, ok to let soap and water run over the area but do not scrub the area 

  • Keep clean and dry 

  • Monitor for signs of infection such as worsening pain, redness, swelling, drainage, or fever

  • Avoid use of bacitracin/neosporin/other topical produects, as they may dissolve the dermabond sooner

PRO

  • Fast

  • Requires fewer supplies 

  • More cost-effective

  • Less painful 

  • Doesn’t require subsequent visit for suture/staple removal

CONTRAINDICATIONS

  • Insufficient hair 

  • Scalp lacerations >10 cm 

  • Highly contaminated wounds

  • Macerated or irregularly shaped wounds 

  • Wound under high tension 

  • Active bleeding 

PATIENT POPULATION TO CONSIDER USE OF THIS TECHNIQUE

  • Children 

  • Patients with active intoxication/agitation/psychiatric disturbances

  • Elderly patients with dementia 

  • Patients on the autism spectrum or those with other sensory processing disorders who may poorly tolerate injections of local anesthetic or remaining still for sutures/staples

EVIDENCE

Per a randomized control trial, “the hair apposition technique was dominant over standard suturing in that it was more effective and resulted in a cost savings of USD 28.50 (95% confidence interval USD 16.30 to USD 43.40) per patient compared with standard suturing because of reduced equipment needs, shorter medical staff time required, no need for another visit to remove sutures, and lower complication rates.” [2]

AUTHOR: Dr. Amy Tronnier is a current fourth year resident at Brown Emergency Medicine Residency

FACULTY REVIEWER: Dr. Dina Gozman is an assistant professor/clinician educator at Brown Emergency Medicine

REFERENCEs

  1. Admin, F. (2021, November 27). Hair apposition. Sinai EM. https://sinaiem.org/foam/hair-apposition/ 

  2. Ong ME, Coyle D, Lim SH, Stiell I. Cost-effectiveness of hair apposition technique compared with standard suturing in scalp lacerations. Ann Emerg Med. 2005 Sep;46(3):237-42. doi: 10.1016/j.annemergmed.2004.11.022. PMID: 16126133.

  3. Hock MO, Ooi SB, Saw SM, Lim SH. A randomized controlled trial comparing the hair apposition technique with tissue glue to standard suturing in scalp lacerations (HAT study). Ann Emerg Med. 2002 Jul;40(1):19-26. doi: 10.1067/mem.2002.125928. PMID: 12085068.

  4. Trick of the trade: Hair apposition technique (hat trick). (n.d.). https://www.aliem.com/trick-of-trade-hair-apposition/ 

  5. https://lacerationrepair.com/techniques/alternative-wound-closure/hair-apposition-technique/

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