44 - Nail Pathology

Question 1

Nail anatomy

Answer 1

• IMPORTANT the area from the lunula
  (half-moon), to the skin under the eponychium
  is where the matrix is produced
• The remaining portions of the nail do NOT
  produce any new nail or nail growth
• You need to focus your TREATMENT on
  eliminating growth centers of the nail

Question 2

Hyponychium

Answer 2

• Hyponychium: free edge distally

Question 3

Eponychium

Answer 3

• Eponychium: undersurface of posterior nail fold (produces cuticle

Question 4

Matrix

Answer 4

• Epithelium overlying nail bed dermis that extends over the base of the distal phalanx to the distal edge of the lunula

Question 5

Nail bed

Answer 5

• The nail bed includes everything distal to the lunula
• Does NOT produce any portion of the nail plate
• Includes a thin layer of keratin that assures firm attachment with nail and, at same time, allows it to slide over bed

Question 6

Arrangement of nail plate

Answer 6

• Example of how the matrix sits on top of the dermis and runs
  from the base of the distal phalanx to the lunula***

Question 7

Nail pocket

Answer 7

• The nail pocket or space is sealed proximally by the cuticle and distally by the hyponychium
• This is what seals the nail plate off to prevent bacterial or fungal infection

Question 8

Cuticle

Answer 8

• Formed by the free margin of posterior nail fold, and mostly, from horny layer of the eponychium
• Serves as a barrier against bacterial infection, which is why patients sometimes develop an infection following a manicure or pedicure in which the cuticle is removed

Question 9

Matrix

Answer 9

• Convex band of highly proliferative epithelium
• 80% of nail produced by proximal half of matrix
• What you see under the lunula does NOT produce as much nail as what you see under the posterior nail fold
• Activity is higher in proximal portion so nail is naturally curved in convex shape proximal to distal
• Due to the arrangement of the matrix from proximal to distal, always take an incisional biopsy of the bed with the long axis of the incision parallel to the long axis of the nail to avoid minimal damage to the matrix and future nail growth

Question 10

QUESTION: The matrix of the nail…
o Covers the entire surface of the nail bed
o Extends over the base of the distal phalanx to the lunula
o Along with the nail bed, produces the nail plate
o Is most active under the lunula
o Nail bed biopsies should be oriented transversely

Answer 10

Answer: 2

Question 11

DuVries technique

Answer 11

• Remove large section of skin (without nail) from the side
  of the toe with two semi-elliptical incisions closed with stitches
• Designed to relieve all soft tissue pressure from side of in-growing nail
• Removes the skin in order to give the nail more room to grow
• There is a lot of bacteria to begin with (inter-digitally especially) – does
  not take much of a break in the skin to create an infection

Question 12

Partial and total nail AVULSION

Answer 12

• Avulsion: removing the offending portion of the nail, which is acting like a foreign body
• Usually reserved for first-time nail removal
• Nail will re-grow, often with a change in shape (thicker or more in-grown in nature)
• Usually reserved for paronychias, subungual hematomas, partial traumatic nail avulsions
• Offending portion of nail removed, but matrix left intact – DO NOT REMOVE THE MATRIX***
• The act of surgically removing the nail plate over the matrix all the way down the nail plate, will typically cause the new nail that grows back to be somewhat deformed – either thicker or in-grown again – Need to inform you patients of this

Question 13

Opinion regarding avulsion

Answer 13

• Get rid of the foreign body (offending nail) then treat the infection locally
• There is some thought within the field that at the first sign of an in-grown toe nail, we should do a matrixectomy (nail matrix is permanently removed)
• We apply phenol to the site of removal when doing matrixectomies, which is an acid that kills the bacteria, but also leaves a chemical burn
• The fact here is that if you are doing a matrixectomy with phenol to an actively infected ingrown toenail, the bacteria that are left behind will feast on the tissue left over from the chemical burn
• The idea behind those who do it is that the phenol (acid) will kill the bacteria, but there is no evidence that it is actually effective in vivo

Question 14

Partial MATRIXECTOMIES

Answer 14

Matrix is permanently removed along medial and/or lateral borders with corresponding overlying nail plate
o Phenol and Alcohol (P&A)
o NaOH and Acetic Acid
o Winograd
o Frost
o Miscellaneous matrix ablation techniques

Question 15

Total MATRIXECTOMIES

Answer 15

Entire nail matrix is removed with entire toenail
o P&A, NaOH
o Zadik (Quenu)
o Whitney
o Kaplan or mini-Kaplan (not going to talk about – uncommon, primitive)
o Terminal Syme

Question 16

Phenol and alcohol technique – PARTIAL MATRIXECTOMY

Answer 16

• Nail is removed with nail splitter, nail matrix is curetted and skin is protected by Vaseline
• Phenol (88% carbolic acid) applied to matrix by Q-tip in three 30 sec. applications (buns the skin)
• Phenol is “neutralized(?)” by 70% isopropyl (rubbing) alcohol (can’t actually neutralized an acid with an alcohol, but it does irrigate it somewhat)
• Wear protective eyewear – medical emergency if you get this in your eye

Question 17

Steps of a partial matrixectomy with phenol and alcohol

Answer 17

• The first step is to anesthetize the toe, then apply a tourniquet to block blood flow to the toe (to prevent it from diluting the phenol which will be applied)
• You then remove the offending nail, making sure your cutters reach under the posterior nail fold where the matrix begins – twist in circular motion away from nail plate
• Then curette the nail bed, apply Vaseline to surrounding skin, apply phenol to site (3 x 30 sec.) which turns black on contact with blood, clean with alcohol, apply dressing (good against burns)

Question 18

NaOH and acetic acid – PARTIAL MATRIXECTOMY

Answer 18

• Same as phenol and alcohol partial matrixectomy, but…
• 10% NaOH chemically destroys matrix and is neutralized by 5% acetic acid (vinegar)
• Nothing in the literature proves that this works any better than a phenol and alcohol
• He has found it to be no different in terms of patient outcome than phenol and alcohol
• If P&A doesn’t work the first time, don’t try this, try a different procedure all together

Question 19

Post-op care for P&A (“Mahoney Method”)

Answer 19

• Apply dressing with Silvadene®, gauze, Kling (Silvadene: DO NOT USE ON A PATIENT WITH A SULFA ALLERY***)
• Keep dry and intact until following a.m.
• Soak 5 minutes in warm, soapy water BID, followed by 2 drops of Cortisporin Otic Suspension® (This is an EAR DROP which contains Neomycin, Polymyxin B, 1% Hydrocortisone - $40 per bottle, but still worth it)
• Then apply a Band-Aid or gauze
• Air dry as much as possible when in a clean environment (He has found that the more he keeps it moist, the longer it takes it to heal and the higher the risk for infection)
• Avoid enclosed shoes for 1 week – it will be almost completely healed in 1 week

Question 20

Mahoney method for follow up

Answer 20

• After 1 week, discontinue soaks and otic drops
• Apply betadine solution or Bactine® BID for 3-7 days
• Return to enclosed shoes
• Opinion: Avoid use of ointments or creams after initial dressing

Question 21

Winograd technique

Answer 21

• Wedge of skin and nail plate removed down through
  matrix to bone with scalpel – Go until you HIT BONE***
• One incision longitudinal through nail, second converging
  incision through soft tissue along nail border
• Bone is rasped then incision closed with sutures (to prevent oozing)

Question 22

Frost technique

Answer 22

• One longitudinal incision through nail plate extending from tip to skin proximal to nail plate
• Second incision at right angle to first extending away from nail plate at base of first incision
• Reflect back flap, remove nail plate and matrix down to bone, rasp bone
• Suture wound closed – SAME thing as Winograd, just remove less skin

Question 23

Miscellaneous matrix ablations

Answer 23

• Nail is removed completely
• Matrix destroyed by hyfrecation, negative galvanic current, radiofrequency, CO2 laser, osteotripsy (utilizes high-speed rotating burr to remove matrix down to bone)
• Tend to not be as effective as phenol and alcohol

Question 24

P & A or NaOH/acetic acid – TOTAL nail removal

Answer 24

• Nail removed in its entirety by utilizing mosquito hemostat to free up dorsal nail fold and separate nail plate from nail bed
• Utilize chemicals for 3, 45 second applications

Question 25

Nail avulsion – TOTAL

Answer 25

• You are taking one end of the hemostat, pushing it under the nail until you meet resistance
• Slide it back and forth to free nail, elevate nail plate, repeat on other side, nail will pop off

Question 26

Zadik (Quenu) – TOTAL nail removal

Answer 26

• Nail plate removed
• H-shaped incision made with connecting incision placed
  proximal to the eponychium (H-SHAPED INICISON IS THE HALLMARK **
• Proximal skin reflected and matrix beneath is excised to bone
• Proximal and distal skin flaps sutured together
• May need to extend distal area medially and laterally or plantarly so that it will meet the proximal flap adequately

Question 27

Terminal Syme – TOTAL nail removal

Answer 27

• Remove nail plate and matrix down to bone with circumferential incision around nail plate
• Remove distal 1/3 of distal phalanx to create less tension for closure
• Suture utilizing plantar flap which advances dorsally to meet proximal incision
• **You should NOT just use this for a normal nail removal, but you WILL use this for osteomyelitis ONLY **

Question 28

Post-op care for terminal Syme

Answer 28

• Treat as you would for any incisional surgery
• Keep toe dry for 1 week (due to high bacterial load in the area)
• After 1 week, dress daily with betadine solution and gauze
• Use surgical shoe until stitches removed (2 weeks)

Question 29

Phenol & Alcohol

Answer 29

• This will be your bread and butter – be VERY proficient at this
• 5-10% of recurrence no matter how careful you are – TELL YOU PATIENTS THIS
• Just some of it will come back or the whole thing will come back
• P&A is still a very nice procedure for you to have in your tool kit
• Helps to “pay the bills”
• Get good at this – it will help you in your career

Question 30

Which procedure does not involve removing or rasping bone?
o	Du Vries
o	Winograd
o	Frost
o	Phenol and alcohol
o	Terminal Syme

Answer 30

Answer: 1 and 4

Question 31

The nail surgery that involves an “L” shaped incision along the nail border through the nail plate is called:
o	Winograd
o	DuVries
o	Terminal Syme
o	Frost
o	Zadik

Answer 31

Answer: 4