Nail bed injuries

Learning outcomes

• Understand the relationship between anatomy , functions and injuries of the nail bed

• Develop repair and reconstruction techniques for the injuries and their complications

Nail bed lacerations

• Remove nail and inspect nail bed• Nail fold may be elevated using back

cuts at the corners• Simple laceration – 7/0 chromic sutures• Repair under magnification• Limit debridement – avoids tension on

repair and prevent scarring• Replace nail plate or cover with artificial

sheet – protects and moulds nail bed

Anatomy of the nail complexMacroanatomy

Production of the nail• Onchyn – keratinous material

produced by the death of the germinal cells

• Nail growth slows after the age of 30 years

• Produced in 3 areas• Germinal matrix – 90%• Sterile matrix – adherence• Dorsal roof – nail shine

Nail vascular supply

• From volar digital arteries• Large branch to the pulp• Branch to the paronychium• Branch to the proximal nail fold• Multiple small branches into the nail

bed• Radial vessels are larger on the ring and

small finger.• Venous return is in a random fashion

over dorsum

Types of Nail Injuries• Crush injuries• Sharp laceratons

• likely to result in tip amputations

• Avulsion• Iatrogenic

• Inadequate phalangeal reduction

• Placement of fixation pins

• Nail biting/ flicking of the eponychium

Basic principles

• Injuries may involve several anatomic structures• Loss of germinal matrix results in no hard nail growing• Loss of sterile matrix results in non-adherence • Radiographs to evaluate assoc. fractures

Paronychial injuries

• Simple lacerations – repaired primarily• Loss of part of the paronychium

• VY advancement• Cross-finger flap• Thenar flap

• Dorsal roof laceration • Primary suture• Loss of tissue – grafting needed

Associated DP fractures

• 50% of nail bed injuries• Comminuted tuft fractures

• Can be stabilised by the avulsed nail with figure of eight suture

• Proximal DP # result in nail deformities• Adequate reduction with crossed K-

wires• Salter I of the DP can present as avulsed

nail sitting on the eponychium – accurate reduction needed

Subungual Haematoma

• If nail plate still adherent – trephinization

• Using cautery• Heated paper clip• Needle

• Nail bed injuries may be missed• Partially avulsed nail plate

• Remove and inspect• Leave in place

Complex lacerations

• Accurate determination of the damaged tissues

• Replace like with like• Complex stellate lacerations

• Meticulous re-apposition• Inspect under surface of nail plate

Avulsions • Look under avulsed nail• In small avulsions replace nail• Loss of sterile matrix• Graft from adjacent sterile matrix• Loss of >50%- graft from toe/adjacent finger

Loss of germinal matrix

• Graft of 1cm can take• Delayed to determine

viability of nail• Composite graft from

toe/finger • Acutely – less scar tissue

and better blood supply but more risk of infection

Partial amputations

• Ablate nail bed completely• Cover the tip• Shorten the nail bed• Hook nail - Unsightly and interferes with function• Loss of nail bed but reasonable bony support – combination of local

flap and nail bed graft

Eponychial loss

• After trauma and tumour resection

• Any excision should be replaced with a composite graft

• Reconstructing the dorsal roof of the nail

• split-thickness sterile matrix graft on the deep surface of the local flap

Onycholysis

• Non-adherence• Caused

• Trauma• Irritation• Dissolving of hyponychial plug• Age• Onychomychosis

• Scarring in the sterile matrix• Narrow – excised and primary sutured• Wide - grafted

Split nails

• Longitudinal scar• Removal of nail• Narrow, diagonal or transverse –

excision and suturing• Longitudinal – multiple z-plasties• Wide

• Split thickness sterile matrix graft• Full thickness germinal matrix graft• Split thickness graft of germinal

matrix do not produce nail

• Horizontal scar – double nail

Bone irregularities

• Osteophytes• Post traumatic inclusion cysts of

sterile matrix• Deformity of nail and erosion of

bone• Curettage of cysts

• Enchondromas• Curettage and bone graft

• Fish-mouth incision

Nail absence

• Congenital or traumatic• Skin graft• Artificial nail• Microvascular transfer• Non-vascularised composite graft

• less reliable • better results in children

Tech Hand Up Extrem Surg. 2005 Mar;9(1):42-6.The aesthetic mini wrap-around technique for thumb reconstruction.Adani R1, Marcoccio I, Tarallo L, Fregni U.

Pincer nail

• Thumb and great toe• Pain• Trauma, tight shoes, hereditary• Nail bed becomes neuro-

vascularly compromised• Nail removal• Excision of paronychium• Freeing paronychium from

periosteum

Hooked nail

• Growing nail follows nail matrix• Tight closure of finger tip amputation• Loss of bony support

• Absent distal phalanx• Trim nail bed• Replace bone

• Shorten nail• Release pulled over nail bed – V-Y• Bone graft

Antenna procedureJ Hand Surg Am. 1983 Jan;8(1):55-8.The "antenna" procedure for the "hook-nail" deformity.Atasoy E, Godfrey A, Kalisman M.

Br J Plast Surg. 1992 Nov-Dec;45(8):591-4.Trimmed second toetip transfer for reconstruction of claw nail deformity of the fingers.Koshima I1, Moriguchi T, Umeda N, Yamada A.

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