ORIGINAL ARTICLES
A New Onychocryptosis Classification and Treatment Plan
Alfonso Martínez-Nova, Lic Pod*
Raquel Sánchez-Rodríguez, Lic Pod*
David Alonso-Peña, MD*
Onychocryptosis is a pathologic condition of the nail apparatus in which the toenail damages the nail fold. It is a common condition provoking pain, inflammation, and functional
limitation. It principally occurs in the hallux. Onychocryptosis is one of the most frequent
complaints regarding the foot and accounts for many clinical consultations. The disorder
has been classified in terms of the stages of the pathologic condition. In our practice, we
discovered a clinical entity that was not previously classified in the literature. We classify
onychocryptosis into stages I, IIa, IIb, III, and the new stage IV. A treatment plan is offered
for each stage of this classification, with both general and specific indications given. In
onychocryptosis treatment, it is important to select the surgical technique best suited to
the patient’s particular clinical situation. (J Am Podiatr Med Assoc 97(5): 389-393, 2007)
Onychocryptosis is a pathologic condition of the nail
apparatus in which the toenail damages the nail fold.
It is a common condition that provokes pain, inflammation, and functional limitation. It principally affects the hallux, although it can also occur in the
lesser toes. Onychocryptosis is more frequent in men
(62%) than in women (38%). Although all age groups
are affected, most patients are adolescents in the
first and second decades of life.1 The fibular canal is
more often affected than the tibial canal, in a proportion of 2:1.
The cause of the condition in childhood and adolescence is usually rounded trimming of the toenails, cutting with unsuitable instruments, or onychophagia.
Other conditions conducive to the condition are hyperhidrosis, wearing inappropriate footwear, direct trauma, biomechanical alterations, pathologic curvature of
the nail plate, surgical iatrogenic conditions, excessive
weight, and the first toe being longer than the others.
Congenital onychocryptosis is an infrequent form of
presentation, believed to be due to intrauterine trauma
or hereditary transmission.2 Heifitz3 divided onychocryptosis into three stages. Recently, Mozena4 refined
this classification, establishing four stages:
*Podiatry, Department of Nursing, University of Extremadura, Cáceres, Spain.
This article is a summary of the main part of MartínezNova A: Podología: Atlas de Cirugía Ungueal, Editorial
Médica Panamericana, Madrid, 2006, and is adapted with
permission of the publisher.
Corresponding author: Alfonso Martínez-Nova, DPM,
Centro Universitario de Plasencia, Avda. Virgen del Puerto
nº 2, 10600 Plasencia, Cáceres, Spain.
• Stage I (inflammatory stage). This stage is
characterized by the presence of erythema, slight
edema, and pain when pressure is applied to the lateral nail fold. The nail fold does not exceed the limits
of the plate (Fig. 1).
• Stage II (abscess stage). This stage is divided
into two substages. In stage IIa the pain increases
and there is edema, erythema, and hyperesthesia.
There may be serum drainage and infection. The nail
fold exceeds the nail plate and measures less than 3
mm (Fig. 2). Stage IIb has symptoms similar to stage
IIa. The hypertrophic fold exceeds the plate and
measures more than 3 mm (Fig. 3).
• Stage III. In stage III, the symptoms worsen,
with granulation tissue and chronic hypertrophy of
the nail fold. The granulomatous or hypertrophic tissue largely covers the nail plate (Fig. 4). If onychocryptosis is not properly treated, it may progress even
further, resulting in serious chronic deformation of
the toenail, nail folds, and distal fold.
We define a stage IV, which completes Mozena’s
classification. Stage IV results from evolution of stage
III, with serious chronic deformity of the toenail, both
nail folds, and the distal fold (Fig. 5). The difference
between stages III and IV is the distal hypertrophy.
Indications for Nail Surgery
Nail surgery is indicated when the patient has pain
and functional disability; in cases of recurrent onychocryptosis, surgical relapse, or iatrogenic nail dis-
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Figure 1. Stage I onychocryptosis.
Figure 2. Stage IIa onychocryptosis.
Figure 3. Stage IIb onychocryptosis.
Figure 4. Stage III onychocryptosis.
tural deformities of the nail, restore the longitudinal
trajectory of the nail plate, reestablish the morphological and normal physiologic features of the nail folds,
prevent painful processes and infections, and conserve the biomechanical function of the nail plate.
The ultimate aim is to completely recover the functionality of the nail apparatus.4
Discussion
Figure 5. Stage IV onychocryptosis. (Reprinted with
permission from Martínez-Nova.1)
orders; and when conservative treatments have failed.
The surgery should have several aims, with the overall objective of restoring the integrity of the nail apparatus. The surgical procedure should correct the struc-
In the medical, dermatologic, and podiatric medical
literature, various surgical techniques have been described to treat onychocryptosis. The ideal surgical
procedure should result in a high level of patient satisfaction (both functional and aesthetic), a rapid return
to normal activities, and a low rate of recurrence. Although an attempt has been made to establish a “standard technique” that will resolve onychocryptosis in
most cases, there is no scientific evidence that any
single technique is the procedure of choice in all cases.
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Despite this lack of scientific evidence for the superiority of any one technique, many studies5-8 have
shown greater success with the phenol-alcohol technique compared with other techniques. These studies
show high rates of efficacy (80% to 95%) and low recurrence rates (approximately 2% to 5%). On the negative
side is a 2- to 5-week recovery time,9 with the inconvenience that this represents for the patient. Moreover, chemical matrixectomy may destroy too much
or too little tissue because it is not a precise technique. Many other variables can influence the effectiveness of chemical matrixectomy, including tissue
hydration; bleeding, which can cause dilution of the
application; and the shelf life of the chemical used,
which can affect its concentration. Nonetheless, the
phenol-alcohol technique is clearly the most extensively studied and practiced technique. It is simple to
perform, requires no complex instruments, has a
broad range of indications, and is widely endorsed in
the dermatologic and podiatric medical literature.
The phenol-alcohol technique can be performed in
the presence of concomitant infection,10 and Giacalone11 demonstrated that it can be applied to diabetic
patients, for whom it presents no differences in healing time or postsurgical complications. The use of
sodium hydroxide, less prevalent in the podiatric
medical community, has the same advantages as phenol, but with considerably less tissue destruction.12
Other studies, however, have found no significant differences between mechanical resection of the matrix
and phenolization of the matrix.13 This last study recommends resection of the matrix to avoid the use of
a toxic substance such as phenol. Persichetti et al14
affirm that simple excision of the matrix using mechanical procedures (with a curet or scalpel) is most
effective, leading to fewer complications and infections and with a shorter healing time.
The use of physical methods to perform the matrixectomy, such as carbon dioxide laser dissection
or electrodissection, have also been discussed.15, 16 Although they are important and effective surgical
methods, they are relatively expensive.
Most of the reports we found in the medical literature were retrospective studies; only two were prospective. They consisted of randomized controlled clinical
trials comparing two techniques (phenol versus mechanical resection of the matrix with curet or scalpel).
One of these two studies suggests using the phenol
technique,15 and the other recommends mechanical
resection of the nail matrix.13 The findings differ because the aesthetic and functional results depend not
only on the technique used but also on the skill of the
professional, the recovery protocol, the appropriate
selection of the patient, and other factors. The podi-
atric medical community must undertake scientific
studies and controlled clinical trials to obtain demonstrable scientific parameters as part of evidencebased podiatric medical research.17 It is important to
offer a surgical solution for each stage of onychocryptosis, selecting the appropriate technique for the
patient’s particular clinical situation.
Treatment Algorithm According to the
Stage of Onychocryptosis
The surgical techniques used are classified into four
groups according to the stage of onychocryptosis
(Fig. 6).
Excision of the Spicule and Partial
Matrixectomy: Suppan I Technique
General Indication. Onychocryptosis affecting the
nail plate without hypertrophy of the nail fold. The
technique consists of excision of the affected portion
of the toenail and partial mechanical matrixectomy
(with curet or scalpel).18, 19
Indications According to Stage
• Stage I
• Adult or elderly patients, in whom tissue-regeneration capacity is reduced and likelihood of recurrence is lower.
• Patients with insulin-dependent diabetes. In patients with some vascular risk or poor control of their
diabetes, after previous stabilization of the vascular
situation and glycemia, this technique is preferred to
phenol-alcohol to avoid complications caused by the
burn.
Chemical Partial Matrixectomy:
Phenol-Alcohol Technique
General Indication. Onychocryptosis affecting the
nail plate with hypertrophy of the nail fold of less
than 3 mm. In these cases, excision of the portion of
affected toenail and phenol partial matrixectomy are
performed.20-22
Indications According to Stage
• Stage I
• Stage IIa
• Young or adolescent patients because they have
great tissue-regeneration capacity. The phenolization
ensures a low recurrence rate.
• Patients with controlled type 1 or 2 diabetes. The
phenol-alcohol technique is safe in diabetic patients
who have no vascular risk and good control of their
diabetes.
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Onychocryptosis
Stage I
Stage IIa
Stage IIb
Stage III
Stage IV
Erythema, slight
edema, and pain.
Increased pain,
edema, erythema,
hyperesthesia,
serum drainage,
and/or infection.
Increased pain,
edema, erythema,
hyperesthesia,
serum drainage,
and/or infection.
Granulation tissue
and chronic hypertrophy of the nail
fold.
Serious chronic
deformity of the toenail, both nail folds,
and distal fold.
Nail fold does not
exceed the limits of
the nail plate.
Nail fold exceeds
the nail plate
< 3 mm.
Nail fold exceeds
the nail plate
> 3 mm.
Granulomatous or
hypertrophic tissue
widely covers the
lateral nail plate.
Hypertrophic tissue
completely covers
lateral, medial, and
distal nail plate.
Adults
Young patients
Suppan I
Phenol
Type 1 DM
Controlled
Type 1 or 2 DM
Suppan I
Aesthetic
reconstruction
Winograd
Young patients
with tibial/fibular/distal
hypertrophy
Winograd
Phenol
Adults
Phenol total
matrixectomy
Young
patients
Phenol
Figure 6. Stage and treatment algorithm. DM indicates diabetes mellitus.
Wedge Resection of the Toenail and Nail Fold
Aesthetic Reconstruction Technique. General Indication. Onychocryptosis affecting the nail plate
with hypertrophy of the nail fold exceeding 3 mm.
These cases involve excision of the affected portion
of the nail plate, partial matrixectomy, and wedge extirpation of the hypertrophic nail fold and the nail
bed. The hypertrophic fold is cleared from the matrix
zone, below the eponychium to the distal end of the
toenail (Fig. 7). No cutaneous incision is made, and
therefore no stitches are required.23, 24
Indication According to Stage
• Stage IIb
Winograd Technique. General Indication. Onychocryptosis affecting the nail plate with hypertrophy
of the nail fold greater than 3 mm. These cases involve excision of the affected portion of the nail
plate, partial matrixectomy, and extirpation of the hypertrophic tissue.25, 26
Indication According to Stage
• Stage III
Figure 7. Wedge resection of the lateral fold using the
aesthetic reconstruction technique. (Reprinted with
permission from Martínez-Nova.1)
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Total Matrixectomy
General Indication. Onychocryptosis with dystrophy of the nail folds and distal folds. Nail dystrophy.
Nail excision and total matrixectomy with phenol is
performed.27-30
Indication According to Stage
• Onychocryptosis in stage IV adult patients
• Onychogryphosis, onychodystrophy
• Chronic hypertrophy of the distal and lateral folds
In this stage of our classification (stage IV), the lateral and distal folds are considerably hypertrophied,
and the nail is affected. There are two treatment options. The first option is three Winograd procedures
for tibial/fibular/distal hypertrophy. This procedure is
indicated in young patients to conserve the integrity
and function of the nail apparatus. The second option
is phenol total matrixectomy, which must be performed in adult patients. If other disorders are present, such as onychomycosis or onychodystrophy,
phenol total matrixectomy might be the better option.
If the nail fold is widely affected, the Kaplan31 technique should be considered.
Conclusion
Correct management of onychocryptosis requires
identification of the stage and evaluation of the affected tissues. Nail surgery should be considered in
cases of pain, recurrent onychocryptosis, surgical relapse, and failure of conservative treatment. It is important to select the surgical technique that is best
suited to the patient’s particular clinical situation.
Financial Disclosures: None reported.
Conflict of Interest: None reported.
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