Keywords
nail - finger - free flaps - finger injuries - surgical flaps
Introduction
Similar to the face, the hand is always exposed. Despite good hand function, many
patients with finger defects or deformities may have cosmetic impairment. Therefore,
finger reconstruction must be high quality not only in terms of function but also
in terms of aesthetics.
The wrap-around flap (WAF) has become popular for thumb reconstruction because it
provides functionally and cosmetically excellent results. However, if the nail of
the great toe is totally harvested for reconstruction of a finger with WAF, the outcome
may be a reconstructed finger that is too thick compared with the contralateral finger.
Therefore, various modifications have been reported, including the following three
methods: partially harvesting the nail, thinning the flap on the plantar part, and
combining a small vascularized partial toenail flap and a local finger flap.[1]
[2]
[3]
[4]
[5] However, the partial nail transplantation tends to result in a missing nail margin,
meaning a finger that appears to have no lateral nailfold on one side.[6]
[7] Moreover, the natural roundness from the proximal to the lateral nailfold tends
to be lost. For these reasons, some surgeons do not think the partial nail transplantation
should be performed.[6]
[7]
Reconstructing a cosmetically natural nailfold is a significant challenge in finger
reconstruction. Nailfold reconstruction techniques are required that are easy to perform,
are simple in terms of complexity and understanding, and produce stable results. However,
few studies have investigated these techniques. Based on direct experience with using
partial nail transplantation for the WAF, this author–surgeon devised simple methods
to reconstruct natural lateral and proximal nailfolds and describes these techniques
and results herein.
Idea
The WAF design for the great toe is as follows: the nail width is 1 to 2 mm wider
than the contralateral fingernail, and the skin reconstructing the pulp is about the
same size as the contralateral finger. These measurements are based on research describing
the author's 20 WAF cases, which showed that the average width reductions for the
distal phalanx included in WAF was 1.2 mm and the flap circumference at the proximal
nailfold was not greatly changed.[8] It is important that the WAF design includes the skin area of the lateral nailfold
to be reconstructed.
The area of the proximal nailfold is elevated from the nail plate up to about half
of the nail to advance it forward ([Fig. 1]). To ensure blood circulation, it is important not to damage the veins of the proximal
nailfold during elevation. Harvesting the nail is performed using the partial nail
and dorsal split distal phalanx of the great toe. The interphalangeal joint and plantar
cortical bone of the great toe are preserved. This approach is a modification of the
Doi method to partially harvest the width of the nail and the distal phalanx.[9]
[10] The plantar part of the WAF is elevated as a thin flap as thin as the finger pulp
to avoid becoming a bulging pulp and ensure that it is not elevated above the periosteum
or paratenon.[10] Particularly, the reconstructed part of the lateral nailfold and fingertip is elevated
with a small portion of subcutaneous fatty tissue.
Fig. 1 Dorsal flap elevation. The proximal nail fold is elevated from the nail plate sufficiently
to advance it forward.
The author considered that volar flap tension occurs regardless of the method used
in a direction away from the reconstructed lateral nailfold. This causes a loss of
lateral nailfold volume, which subsequently results in a missing nail margin ([Fig. 2]). Therefore, the author devised an approach to maintain the amount of tissue needed
for reconstructing the lateral nailfold. A single thread was passed through the nail
plate to suppress the displacement of the volar flap so that the volume of the lateral
nailfold can be maintained ([Fig. 3]). Careful attention is needed for this step: if tying this thread tightly, flap
blood circulation may become poor. Therefore, this thread must be tied while checking
the flap color after flap revascularization.
Fig. 2 Cause of the missing nail margin. If simply suturing the volar flap, the volume of
the lateral nail fold is lost due to the tension of the volar flap: (A) ideal outcome; (B) potential actual outcome; (C) missing nail margin. Red arrow: direction of the flap tension.
Fig. 3 Lateral nailfold reconstruction. A single thread suppresses the displacement of the
volar flap: (A) cross-section view; (B) intraoperative view, before suturing. Black arrow: thread for the lateral nailfold reconstruction.
Further, the proximal nailfold is advanced to the position balanced with the contralateral
proximal nailfold angle. The proximal nailfold can be easily advanced without tension
because the half proximal nailfold is elevated from the nail plate when the flap is
harvested. The fingertip and lateral nailfold skin are not forcibly closed, resulting
in an open wound ([Fig. 4]).
Fig. 4 Proximal nailfold advancement and maintaining the volume of lateral nailfold. The
tip and lateral nail fold are made open: (A) dorsal view; (B) palmar view. Black arrow: advanced proximal nail fold. Red arrow: thread that suppresses the displacement of the volar flap.
Postoperatively, a commonly used topical medication is applied to the wound, and no
other special treatment is required. In most cases, the epithelialization of the open
wound is completed in a few weeks. The suture used for the lateral nailfold reconstruction
is maintained in place for 2 to 3 months. These techniques stably reconstruct the
natural bulge of the lateral nail fold and the natural roundness of the proximal nail
fold, yielding a successful cosmetic outcome ([Fig. 5]). The author used this method of reconstruction in more than 30 cases, of which
flap necrosis occurred in 1 case.
Fig. 5 Postoperative follow-up at 24 months for three cases. Reconstruction outcomes: (A) 55-year-old, index and middle finger; (B) 36-year-old, index finger; (C) 50-year-old, index finger.
The donor site was prepared with sufficient time for granulation to grow, and then
split-thickness skin grafting was performed. Although nail deformity in the donor
site was inevitable, most of the author's patients had few donor-site morbidities,
such as gait impairment and pain.
If the design is too large or the elevated plantar part of the great toe is thick,
the reconstructed finger pulp becomes bulky, but as long as the design includes the
part of the lateral nail fold to be reconstructed, the natural bulge of the lateral
nail fold can be reconstructed using just this one thread. When the reconstructed
finger pulp is bulky, secondary volume reduction surgery is the solution. The secondary
pulp plasty is performed by making a midlateral skin incision to preserve the reconstructed
lateral nail fold, elevating the palmar tissue again, and then reducing the excess
tissue.[10] The presented mattress suture technique is included while closing the wound because
simple skin closure tends to make the preserved nail fold relatively small caused
by postoperative palmar tissue tension.
Written informed consent was obtained from patients for the publication of this article.
This study was approved by the Institutional Review Board of Kansai Electric Power
Hospital (IRB no. 21–114).
Discussion
Reconstruction of a natural nailfold using partial nail transplantation for WAF is
difficult. The author devised an easy nailfold reconstruction technique based on simple
advancement of the proximal nailfold and maintaining the lateral nailfold volume by
a single thread.
Several reports have described lateral nailfold reconstruction in WAF. Hirasé et al
reconstructed a lateral nailfold using the additional local flap in the recipient
finger or the second toe skin flap, which was combined with WAF.[2] Wang et al reconstructed one finger with two osteo-onychocutaneous free flaps taken
from the bilateral great toe.[11] Although their method can be used to successfully reconstruct the lateral nailfold,
it is technically complicated. In the design by Koshima et al, the contralateral nailfold
skin connected only to the great toe tip was added to the partial nail transplantation.[12] In this design, the added lateral nailfold skin was the narrow reverse flap, which
may raise concerns for poor blood circulation in this nailfold skin. In contrast,
the current author's technique uses only a single thread. Therefore, this approach
is definitely simpler and easier than these other approaches, and blood circulation
is stable.
Hirasé et al advanced the proximal nailfold to reconstruct an aesthetic proximal nailfold,
and the current author's technique is based on theirs.[2] In addition to that advancement, Hirasé et al also incised and retracted the contralateral
proximal nailfold angle.[2] However, the contralateral proximal nailfold angle should be able to be reconstructed
without any additional procedures because it has already natural roundness. Furthermore,
separating wide area of proximal nailfold may result in poor blood circulation in
the area. A key feature of the current author's technique is that the proximal nailfold
is separated only up to half of the nail, and no further procedure is performed to
the proximal nailfold. Therefore, this technique for reconstructing the natural proximal
nailfold is also easy to perform and has a low risk of poor blood circulation.
When the wound is closed, the fingertip and lateral nailfold are intentionally maintained
as open with this technique. Few studies have detailed how to close these wounds.
The reason why these wounds are made open is that suturing and closing them often
causes poor blood circulation in these areas due to skin tension. These open wounds
are then contracted and epithelialized, resulting in a naturally rounded fingertip
and lateral nailfold. The critical point of lateral nailfold reconstruction is how
to maintain the volume of the lateral nailfold, not how to close the wound.
Scar formation and collagen remodeling in humans occurs over several months.[13] During this period, the WAF volar flap will contract in the direction away from
the reconstructed lateral nailfold. Therefore, the author keeps the suture used for
lateral nailfold reconstruction in place for 2 to 3 months. Despite the potential
for inflammation and abscess formation due to this suture, such complications rarely
occurred in the author's cases. This lack of complication may be because the suture
was performed with a strength that did not interfere with the local blood circulation
of the flap and did not bite into the flap skin.
Most of the author's patients had few donor-site morbidities. The author's method
preserves the interphalangeal joint, the plantar cortical bone, and much of the plantar
soft tissue of the great toe. These preservations seem to be related to low donor-site
morbidity. The author recommends reoperation of the WAF as a salvage procedure in
case of flap loss because of the low donor-site morbidity and high success rate. However,
the psychological burden on the patient in the reoperation of the WAF is an important
concern that cannot be ignored. In fact, the author recommended another WAF reconstruction
from the contralateral great toe for one case of flap loss, but the patient declined
the offer and instead opted for a prosthetic finger.
The main limitation of the study was that determination of the morphologic improvement
of the nailfold was based on the author's subjective evaluation, rather than objective
data such as the measured value of the lateral nailfold volume or the angle of the
proximal nailfold. Gathering such data will be difficult in terms of study methodology,
but these data are of importance and interest for a future study.
Aesthetic nailfold reconstruction is important in finger reconstruction using WAF.
This study described techniques for aesthetic nailfold reconstruction by advancing
one side of the proximal nailfold and maintaining the volume of the lateral nailfold.
These techniques are simple and are technically easy, and the results are stable.
