Keywords
onion flap - post-burn nail deformity - nail fold reconstruction
Introduction
Abnormalities of fingernail growth and appearance are among the most common deformities
encountered after burn injury to the hand. Abnormalities of the burnt nail apparatus
can be divided into (a) intrinsic, resulting from direct thermal damage to the regenerative
nail matrices and (b) extrinsic, because of contracture of the soft tissues proximal
to the eponychium.[1]
The severity of the nail deformity is usually proportional to the degree of the nailfold
proximal dislocation and can be roughly determined by the extra amount of visible
lunula. Regardless of the mechanism of nail deformity, the key to reconstruction depends
upon the adequate release of retracted eponychium, followed by generous resurfacing
of the resulting defect.
Various techniques used for resurfacing defects include incision of the scarred eponychium
and advancement of the distal segment, flap reconstruction by either distally or proximally
based transposition or advancement flaps, composite graft techniques, and microvascular
transfer.[1] All these techniques demand a secondary donor site and its associated morbidity,
except small advancement flaps where the donor site may be closed primarily. Small
advancement flaps or rotation flaps cannot be used for moderate or severe types of
nail fold contractures. Some procedures are associated with poor cosmetic appearance,
pulp-to-pulp, and lateral-to-pulp (key) pinches that are uncomfortable.[2]
We aim to study Yang's onion flap to release scarred eponychium and nail fold reconstruction
in a single stage. The flap is bipedicled based on residual nailfold on both sides
and advanced to normal position for nailfold reconstruction. Because the scar will
be dorsally located instead of sides, lateral pinch and the light touch of the fingers
are expected to be preserved much better.
Materials and Methods
We conducted a prospective interventional study from September 2016 to March 2018
over a period of 18 months. Inclusion criteria were patients of burn nail deformity
due to retracted eponychium at least 6 months after burns. Exclusion criteria were
patients previously operated for burn nail deformities, nail deformity other than
burn injury, less than 18 years of age, and those with infected nailbeds and local
ulcers.
Methodology
Patients attending the outpatient department as well as inpatients were screened for
nail deformities. A total of 44 nail deformities were operated upon. All cases were
done under general or local anesthesia, and the onion flap procedure as described
by Yang et al[2] was followed to reconstruct the burn nail deformity.
Surgical Technique
All fingers were operated under tourniquet control for ease of dissection. Flap markings
were designed by marking the existing eponychial edge and then the projected eponychial
edge. This gap was restored by advancing the onion flap raised on residual eponychium
superficial to underlying tendons. The bipedicled advancement flap was planned with
lateral bases of at least 5 mm in width. The onion flap tip was usually planned 1 mm
more than the desired advancement and was kept narrow to allow primary closure ([Figs. 1] and [2]). An anchoring suture was taken from the distal end of the flap to the nail pulp.
Yang did not initially describe this suture, but we found it to be a worthwhile modification.
Fig. 1 Onion flap dorsal view.
Fig. 2 Onion flap lateral view.
Viability of flap, hematoma, and infection were recorded in the early postoperative
period. The parameters assessed and recorded till 4 months of follow-up were final
donor site scar appearance, assessed by visual analog scale (VAS) (0: unacceptable
scar to 10: natural appearance),[3] and nail plate appearance, such as the direction of nail growth and the smoothness
of the nail plate, assessed using clinical examination and photographs.
Statistical Analysis
All data were subsequently analyzed with the help of computer software (SPSS statistical
software, version 25.0, for Microsoft Windows, SPSS Inc. Chicago, IL). All values
were expressed as mean and percentages. Qualitative data correlation was done by Chi-square
test. The quantitative data correlation was done by t-test.
Results
A total of 44 fingers (15 patients) were operated on. The mean age of patients was
31.6 years. The mean time interval since burn injury to surgery was 17.8 months, with
a range of 6 to 48 months. All 15 patients had received conservative management for
the primary burn injuries with regular dressings. Of the 44 fingers included in the
study, 35 fingers had flame burns, while 9 had scald injuries. Because the number
of patients of both types of burns was not comparable, the difference in outcome was
not assessed. Out of 44 patients, 11 (25%) were operated on for other contractures
under general anesthesia, and Yang's flap was done simultaneously, while 33 patients
(75%) were operated under local anesthesia under digital or wrist block. The procedure
was successfully done on all fingers. It was done as a single staged procedure in
all patients, and the donor site was closed primarily. Yang's flap was also successfully
done in fingers with scarring on dorsal aspect till distal interphalangeal joint (DIP)
with wider flaps even reaching the middle phalanx ([Figs. 3] and [4]).
Fig. 3 (A) Middle finger with nail plate deformity. (B) Operative photograph. (C) Well-settled flap with improved nail growth at 6 months' follow-up, dorsal view.
(D) Lateral view.
Fig. 4 (A) Post-burn nail deformity middle and ring fingers. (B) Intraoperative photograph of onion flap for middle finger, dorsal view. (C) Lateral view. (D) Improved nail growth seen in the middle finger as compared with ring finger.
Flaps were monitored clinically for 48 hours, after which the primary dressing was
done. Wounds were then dressed on alternate days, and sutures were removed on day
7 and the anchoring suture on day 10. The following findings were noted:
-
Two out of 44 flaps developed partial necrosis of the onion flap; these fingers were
managed conservatively with dressings only. Wounds healed in the two patients in 10
and 12 days, respectively. No further procedures/flaps were required for both of these
patients. The overall complication rate in the early postoperative period was 4.54%.
-
The bulb of the onion flap settled down with time and was less prominently seen at
the end of follow-up in all fingers. The average VAS score was 6.8, indicating good
acceptability ([Fig. 5]).
-
Improvement in nail plate appearance was observed in 26 (59.1%) out of 44 fingers.
There was no improvement in appearance in 18 fingers (40.9%). Improvement was considered
when a crooked, uneven nail was replaced by a smooth and shiny one. These changes
were noted by both the patient and observer during clinical examination and in photographs
([Fig. 3]–[5]). The follow-up period in most patients was 4 months. A longer follow-up is needed
to document an improvement in nail plate appearance as the pace of nail growth is
slow and may not be documented well in 4 months. In a few patients not showing an
improvement in nail appearance, a later release and skin grafting was planned. However,
this intervention was not a part of this study.
-
Preoperatively, patients had reported that deformed nails caused problems other than
aesthetic concerns. Of the 44 fingers, there were complaints of the hindrance of daily
activity with the deformed nails in 28 fingers. The main problems were the entanglement
of nails in clothes, pockets, and the frequent break in nail plates. Of these 28 fingers
with symptoms, 22 fingers (78.57%) reported a symptomatic relief postoperatively,
while six fingers reported no symptomatic relief after the operation. There was a
positive correlation of the reduction in functional problems with restoration of the
horizontal anatomy of the deformed nail plates (19 out of 20 patients reported less
entanglement p-value: 0.01). Only one patient reported that he still suffered nail entanglement
even after a more horizontal nail plate was achieved, in the coronal plane.
Fig. 5 (A) Onion flap at postoperative day 7. (B) Flap at 2 month's follow-up. (C) Well-settled Onion bulb at 6 month's follow-up.
Discussion
A normal healthy nail has a dorsal nail matrix with the eponychium that covers and
protects it. The first case report for the attempt to release scarred tissue and correct
the nailfold was by Barfod in 1974 as a four-stage procedure.[4] Though he attempted to correct the contracture of the DIP joint, an improved nail
appearance was also seen.
Achauer et al used a primarily closed donor site, but the procedure could only be
applied to mildly deformed nails. The author later favored proximally based flaps
for nail deformities and nail fold creation.[5] Distally based flaps have a risk of precarious blood supply if they are raised very
distally, and the digital nerve and vessels can be damaged while raising the flap
leading to a decreased sensation and flap loss.[1]
[6] The proximally-based flaps can have a digital artery or branch included in the flap,
but the flap still has the chance of digital nerve injury. This risk is because earlier
flaps included skin from the finger's lateral side, which often encroached on the
volar aspect. When raised, both proximal and distally based flaps should preserve
the pulp-to-pulp pinch area (the flap is raised on the nondominant ulnar border of
the fingers and the radial border of the thumb). However, it may not always be possible
due to scarring of the skin in the involved finger.[6]
Donelan has described a bipedicled proximally based flap in over 100 cases over 20
years reliably with good results; this technique uses a skin graft to cover donor
site defects.[7]
Yang described the technique for release of scarred eponychium and nailfold reconstruction
in 2012 in 32 fingers with a 100% flap success rate. The technique further modified
the reverse V–Y advancement flap described by the author earlier with primary closure
of the defect.[2] We found the flap to be feasible as a single-stage procedure in 44 fingers.
Early Postoperative Complications
We noted partial flap necrosis in two of our operated fingers. The reason for partial
necrosis seen in two patients in our study could be excessive undermining at the pedicles,
jeopardizing the vascularity of the flap. The bipedicled nature of this flap gives
a good blood supply, leading to a high success rate of the flap noted by us.[8] Donelan et al in 2005 also described their experience with bipedicled flaps to release
scarred eponychium. They described over 100 flaps over 20 years with no instance of
flap loss. Their technique required the closure of the resultant donor site defect
with skin graft like previous other techniques.[7] Flap necrosis is a known complication noted by Alsbjorn in one patient and Yang
in two patients (epidermolysis of the tip).[2]
[5]
The procedure for nailfold reconstruction is a clean case by definition with no contamination.
Meticulous technique and adequate hemostasis before closure prevent the incidence
of hematoma post-surgery.[9]
Scarring
The bulb of the onion flap settles with time. The same was reported by Yang et al
in their study.[2] Donelan et al performed release of scarred tissue and closure of the resultant defect
by a skin graft, the flap used by them for nailfold reconstruction also settled with
time as seen in the postoperative photographs by the patients.[7] Achauer also reported flattening of dorsal flaps over time.[10] This previously documented flattening out of the flap was also seen in our study.
Because the donor site was closed primarily in our study, we did not notice a different
color of the donor site as seen in the report of Donolen et al.[7]
Nail Plate Appearance
We found an improvement in the appearance of the nail plate in 26 (59.1%) out of 44
fingers (mean follow-up: 4.63 months). Yang et al reported improved nail plate appearance
in all fingers (mean follow-up: 7.8 months).[2] Donelan et al, Alsbjorn et al, Achaeur et al have mentioned an improved nail appearance,
but the number of fingers is not mentioned.[5]
[7]
[10]
The nail bed and germinal matrix are not surgically altered directly by our procedure.
The improvement in nail plate appearance is attributed to a more anatomically placed
nail fold. However, when the association of a normal nail fold appearance with a normal
nail plate appearance was tested, it was marginally statistically insignificant (p = 0.081). Further, because the follow-up period in most fingers in our study was
around 4 months and nails grew at around 0.5 cm per week, a longer follow-up would
probably have more patients reporting a normal nail plate appearance. Most of our
patients had flame burns (80%), and 66% of them had other associated contractures,
indicating a more severe burn injury. Many of these patients could have fingers with
direct thermal damage to the nail germinal matrices, in which case the normalization
of nail fold would not affect the nail plate appearance in the respective fingers.
Such patients could be planned for a nail bed transfer.
Symptomatic Relief
Of 28 fingers with symptoms, 22 fingers (78.57%) reported a symptomatic relief, while
six fingers reported no symptomatic relief at the end of follow-up period. Spauwen
also reported symptomatic improvement in all patients operated. Though the effects
of surgery reversed at the end of 1 year in their study, patients still reported symptomatic
relief at the end of 1 year.[11]
Conclusion
Yang's flap is a good option for the correction of nail deformity in burn patients.
It was associated with a low complication rate and improved nail appearance in 60%
of patients. There is also significant symptomatic relief in performing daily activities
after surgery.
