Lecture 2: Onychocryptosis
What shape is the Winograd procedure?
"D"-shaped excision of the nail root and overlying soft tissues
What shape is the Zadik procedure?
"H"-shaped incision and requires excision of both the nail root and the nail bed
What shape is the Frost procedure?
"L"-shaped incision behind the nail plate
Compare the effectiveness of sodium hydroxide vs. phenol.
*Sodium hydroxide more pain* - 10.8 day recovery (vs. 18.02 for phenol) - 95.1% success rate (vs. 95.8% for phenol) Sodium hydroxide causes *less postoperative morbidity* and provides *faster recovery*
What are 4 ways in which onychocryptosis can present?
1. Juvenile ingrown toenail 2. Hypertrophy of the nail fold 3. Pincer or involuted nail 4. Distal nail embedding
Where are the injections made to the medial aspect of the hallux in a hallux block?
1. Plantarly to the plantar medial aspect 2. Dorsal aspect laterally to the dorsal lateral aspect of the hallux
What is a glomus tumor? What are glomus bodies? How does it present?
A benign (but painful) tumor that arises from *glomus bodies* Glomus bodies control shunting of blood for temperature regulation Tender, red, subungual nodule or as a small, subtle, area of blue pigmentation
What is distal nail embedding? It is frequent after what procedure?
A distal ring of tissue develops and nail growth is blocked by the hyponychium Frequent after total nail avulsion
What is a granuloma and how does it appear?
Abnormal growth of the skin which appears angry-looking and very bloody
What individuals are at risk for nail surgery?
Allergy to local anesthetics Coagulopathy Pregnancy PAD
A hallux block is used to anesthetize what part of the hallux? What are the disadvantages?
Anesthetize the hallux DISTAL to the 1st MPJ Disadvantages: loss of proprioception if allowed to ambulate after the procedure
What should be applied for post-op phenol care until healing is complete?
Antibiotic ointment
3rd injection of a hallux block begins where and proceeds how?
Begins at the dorsal lateral aspect of the hallux just distal to the MTP joint Proceed plantarly to the plantar aspect of the hallux
The pain associated with a pincer nail is due to what? What is an important differential diagnosis to rule out with x-ray?
Compression of the distal nail bed leading to severe pain *Subungual exostosis* should be excluded by x-ray examination
What are the pros and cons of conservative removal vs. aggressive removal of an ingrown?
Conservative: - ineffective Aggressive: - effective but cosmetically unacceptable
What phenol procedure is conventionally used? What procedure has a better safety profile?
Conventionally used: 3 swabs for 30 seconds Better safety profile: 1 minute phenol cauterization of the germinal matrix
How do oral antibiotics as an adjunctive therapy affect healing time?
Does NOT play a role in decreasing the healing time or post-procedure morbidity
What is the underlying cause of onychocryptosis?
Foreign body reaction from the presence of nail material in the flesh of the toe
Which nail is most common in onychocryptosis?
Hallux nail
Hypertrophy of the lateral nail fold results in a nail that looks like what? In what direction could this deviate the nail?
Hypertrophic lip that partially covers the nail plate Lateral deviation
What causes a juvenile ingrown toenail?
Impingement of the nail plate onto the nail fold due to *improper nail cutting* A spicule pierces the soft tissue of the nail fold
How is the Fowler procedure done?
Incision that is angled at about 45 degrees from the nail border and excising just the nail root
What is the trade off for using phenol to prevent recurrence of onychocryptosis?
Increase post-operative infection
Where is the spatula first inserted in a nail avulsion procedure?
Inserted DORSALY under the cuticle to separate the nail plate from the overlying proximal nail fold Then inserted PLANTARLY from the distal aspect of the nail to proximal under the proximal nail fold
How does phenol act as a chemical cauterant?
It has protein coagulating power
What is pyogenic granuloma? What is its cause?
Lobular capillary hemangioma, which is a common benign vascular lesion of the skin and mucosa Cause is unknown
What is onychophosis? It's commonly found in what age group?
Localized or diffuse hyperkeratotic tissue that develops on the lateral or proximal nail fold of the space between the nail fold and the nail plate Common finding in the elderly
What causes a distal nail embedding?
Loss of counter-pressure by the disappearance of the nail plate. This allows *dorsal expansion of the distal pulp*.
What supplies the medial side of the great toe dorsally?
One of the two *dorsal digital branches* of the medial dorsal cutaneous branch
What should be included in the differential diagnosis for onychocryptosis?
Onychophosis Pyogenic granuloma SCC Kaposi's sarcoma Subungual melanoma Basal cell tumor Glomus tumor Digital angioleiomyoma Merkel cell Bone pathology
What are causes of hypertophy of the lateral nail fold? What is it characterized by?
Present at birth or due to a chronic ingrown toe nail Characterized by an overgrowth of the soft tissue of the internal portion of the lateral nail fold
How do oral antibiotics effect onychocryptosis?
Relieves initial drainage and discomfort BUT short-lived Inevitable progresses to a more advanced stage of involvement
What should be done to a severely incurvated nail plate?
Removal of the tibial and fibular nail plate borders leaves only a think sliver of remaining nail plate Total nail plate removal is the better choice cosmetically
What happens if the nail grows too quickly or too slowly?
Residual stress can force the nail's curvature to change, resulting in a *painful cut into the surrounding skin*
What type of skin cancer is especially aggressive when *subungual*? What carcinoma is this related to? What is the metastatic potential?
SCC Related to verrucous carcinoma Metastatic potential is low
What should been seen at the proximal portion of the proximal edge of the removed nail?
Should be thin and flexible (like a feather's edge)
What is the Whitney procedure?
Similar to Frost but on both nail border; nail bed is *preserved*
What are the stages of onychocryptosis?
Stage 1: end of toe red with mild swelling, may feel warm and painful, NO pus or drainage Stage 2: toe increasingly red, swollen, and painful, white or yellow pus or drainage, POSSIBLE infection Stage 3: granulation tissue formation, which adds to swelling and discharge of pus, lateral nail fold hypertrophy, more severe infection with fever
How does a subungual/periungual melanoma present? This is highly suggestive of what malignancy?
Subungual pigmentation that does NOT move distally as the nail plate grows --> pigmentation "spill" onto adjacent nail folds Highly suggestive of *malignant melanoma*
Which way is the offending portion of the nail rotated?
TOWARDS the nail while pulling straight out towards the end of the toe
True or false: Subungual/periungual melanomas are locally destructive and highly metastatic.
TRUE
Which nerve supplies the skin on the medial side of the great toe?
The *proper digital nerve of the great toe* from the medial plantar nerve
What nerve supplies the adjacent sides of the great and second toes?
The *two dorsal digital nerve* from the terminal branch of the deep peroneal nerve
What was the conclusion of the study that compared a wedge resection and phenol vs. a wedge resection alone?
The combination procedure gives better long-term results than wedge resection alone Recurrence rates: - Wedge resection and phenol: 4.4% - Wedge resection alone: 17.5%
Where does a hallux block begin?
The dorsal medial aspect of the hallux just distal to the MTP joint (create a wheal)
Where is the ideal location to excise an ingrown nail?
The juncture between the flat central portion of the plate and the curved lateral portion
What are other terms for a pincer nail? How is does it occur?
Trumpet nail, omega nail, involuted nail May be hereditary or acquired
What are the results of cold steel vs. phenolization?
Wedge resection: - recurrence 5.5% - reoperation rate 20% Phenolization: - recurrence 0% - reoperation rate 0%
