The treatment of moderate to severe onychocryptosis with either a wedge resection with or without phenolization or partial nailmatrix resection with phenolization, a randomized controled trial.

Ingrowing toenails, also known as *onychocryptosis* or *unguis incarnatus*, are
a common problem among the general population with a prevalence of 54/10,000
registered patients per year, with a peak between 15 and 24 years of age in
Dutch general practice.(DeLauro and DeLauro 2004; Westert, Schellevis et al.
2005) Ingrowing toenails occur when the periungual skin is punctured or
traumatized by one of the distal angles of the nail plate. This results in a
cycle of invasion by foreign bodies, which is sometimes followed by infection
with signs of inflammation and then repair processes. The person develops a
painful and draining lesion, with the formation of granulation tissue at the
side of the puncture.(Eekhof, Van Wijk et al.; Heidelbaugh and Lee 2009) These
symptoms cause a great deal of discomfort, and they often have an impact on
everyday activities. (Yang, Yanchar et al. 2008)

The most important cause for onychocryptosis is improper trimming of the nail.
Other common causes are tearing nails off, wearing tight shoes. Also the
position of the toe can cause an ingrown toenail. Diabetes, obesity, oedema of
the lower extremities, hyperhidrosis plantares, and heart, renal and thyroid
diseases are risk factors for developing onychocryptosis.(Heidelbaugh and Lee
2009)

There are three stages to classify onychocryptosis: mild (I), moderate (II) or
severe (III). The mild stage is characterized by nail-fold swelling, oedema,
erythema and pain. The moderate stage has the symptoms as in the mild stage,
but this stage leads also to inflammatory granulation tissue, infection,
seropurulent exudate and sometimes ulceration of the nail-fold. In the severe
stage the inflammation is chronic, granulation tissue and sometimes nail-fold
hypertrophy occurs.(Eekhof, Van Wijk et al.; Gerritsma-Bleeker, Klaase et al.
2002; DeLauro and DeLauro 2004)

There are several interventions for onychocryptosis. The group of non-surgical
interventions includes gutter treatment, orthonyxia, band-aid method, soaking
the toe in warm water, placing a piece of cottonwool under the ingrowing
toenail. These options are mostly used in the mild or moderate stages.(Eekhof,
Van Wijk et al.; Heidelbaugh and Lee 2009) The group of surgical interventions
includes radical excision of the nail fold (*Vandenbos procedure*), rotational
flap technique of the nail fold, wedge excision (*Winograd*), partial nail
avulsion (PNA, *Ross*).(Ross 1969; Winograd 2007) The last three treatments can
be combined with chemical, surgical or physical (electrofulguration) excision
of the matrix. The chemical matricectomie is an application of a corrosive
liquid, like phenol or sodium hydroxide. The surgical interventions are used in
the moderate or severe stages.

A recent meta-analysis concluded that surgical interventions are more effective
than non-surgical interventions with gutter treatment in preventing recurrence
of the ingrowing toenail.(Eekhof, Van Wijk et al.) One of the conclusions is
that the addition of phenol to a radical wedge resection is more effective in
preventing recurrence and regrowth than wedge resection alone.(Eekhof, Van Wijk
et al.) However, this conclusion is based on only one randomized controlled
trial from 1988.(Issa and Tanner 1988)
In our hospital, the Isala Clinics Zwolle, every surgeon uses one of the above
described techniques: radical wedge resection, partial nail avulsion with
phenolisation of the nail matrix or a wedge resection with phenolisation.
However regrowth of nail spikes or recurrence of onychrocryptosis does occur.
Based on the conclusion of the meta-analysis we started this randomized
controlled trial to investigate the benefit of additional phenolisation after a
radical wedge resection.

Our research question is if phenolisation in addition to the surgical wedge
resection in patients with moderate to severe onychocryptosis, has an effect on
the occurrence of regrowth of nailspikes and recurrence of onychocryptosis.
Secondary outcome measures are postoperative pain, postoperative analgesic use,
postoperative haemorrhage and patient*s satisfaction 6 months after surgery.

The objectification of the most effective surgical treatment, in which three
operationprocedures are compared.

a single blinded randomized controled trial

wedge resection
wedge resection with phenolization
nailmatrix resection with phenolization

no additional risks for patients participating in this study compared to no
participation.