CLINICAL
RESEARCH
Reverse
Palmar Flaps for Triphalangeal Finger Defects: An Anatomical Study and Case
Series
Martín J. Pastrana,*
Laura Togneri,* Ezequiel Zaidenberg,**
José A. Pastrana,# Carlos R. Zaidenberg**
*Orthopedics
and Traumatology Service, Hospital de Pediatría SAMIC
“Prof. Dr. Juan P. Garrahan”, Autonomous City of Buenos Aires, Argentina
**Musculoskeletal
Study Unit, 1st Chair of Anatomy, School of Medicine, Universidad Nacional de
Buenos Aires, Autonomous City of Buenos Aires, Argentina
#Hand and
Upper Limb Reconstructive Surgery Unit, Sanatorio
Güemes, Buenos Aires, Argentina
ABSTRACT
Objective: To describe
the anatomical consistency of palmar cutaneous branches and commissural
arteries, and to evaluate patients treated with reverse palmar flaps. Materials and
Methods: Anatomical study: five cadaveric hands were analyzed to
assess the consistency of palmar cutaneous branches, as well as commissural and
transverse interphalangeal arteries. Clinical study: patients with palmar
digital injuries in triphalangeal fingers treated with palmar flaps were
included, with no age restriction, no prior surgical history, with or without
associated injuries, and a minimum follow-up of 24 months. Subjective
evaluation included the Visual Analog Scale (VAS) for pain and the QuickDASH score. Objective evaluation included the
two-point discrimination test and goniometric assessment of total active motion
(TAM) according to the Strickland system. Results: The anatomical study demonstrated
consistent palmar cutaneous branches (2–4 branches per flap island), as well as
the presence of commissural and transverse interphalangeal arteries. The
clinical study included 10 patients (8 men and 2 women). Eight short and two
long palmar flaps were performed. The postoperative VAS score was 1/10 and the QuickDASH score was 2.5. Two-point discrimination was 7 mm.
According to TAM (Strickland classification), 6 results were excellent, 3 good,
and 1 fair. Conclusions:
Palmar cutaneous branches and anastomotic systems were found to be
consistent. The reverse pedicled palmar flap proved to be an effective option
for the treatment of digital defects.
Keywords: Reverse
pedicled palmar flaps.
Level of Evidence: IV
Colgajos inversos
del hueco de la mano en defectos de dedos trifalángicos. Estudio anatómico y evaluación de una serie de casos
RESUMEN
Objetivos:
Describir la constancia anatómica
de ramas cutáneas de la palma de la mano y las arterias comisurales, y evaluar a pacientes tratados con colgajos inversos del hueco de la palma. Materiales y Métodos: Estudio anatómico: 5 manos cadavéricas
para analizar la constancia
de ramas cutáneas palmares de la mano, arterias comisurales y transversas interfalángicas. Estudio clínico: pacientes con heridas digitales palmares en dedos
trifalángicos de la mano, tratados
con colgajos del hueco de
la palma, sin restricción
de edad, sin antecedentes quirúrgicos, con o sin lesiones asociadas y un seguimiento mínimo de 24 meses. Las evaluaciones
se realizaron con la escala
analógica visual para dolor, el
QuickDASH, y la prueba de discriminación de 2 puntos y goniometría
del rango de movilidad activa total por el sistema de Strickland. Resultados: El
estudio anatómico demostró la constancia de ramas cutáneas (2-4 ramas por isla)
del hueco de la palma, de
la arteria comisural y transversas
interfalángicas. El estudio
clínico incluyó a 10 pacientes (8 hombres y 2 mujeres).
Se realizaron 8 colgajos
del hueco de la palma cortos y 2 largos. El puntaje posoperatorio de la escala analógica visual fue de 1/10 y el del QuickDASH, 2,5; y la prueba de discriminación de 2
puntos fue de 7 mm. Según el rango de movilidad
activa, 6 resultados fueron excelentes; 3, buenos y
uno, regular. Conclusiones: Las ramas
cutáneas y los sistemas anastomóticos resultaron constantes. El colgajo pediculado inverso del hueco de la palma resultó eficiente
en el tratamiento
de defectos digitales.
Palabras clave: Colgajos pediculados inversos;
hueco; palma.
Nivel de Evidencia: IV
INTRODUCTION
Palmar
injuries of the fingers involving soft-tissue, osseous, or combined defects are
common conditions associated with occupational and recreational activities.
When these injuries involve the distal half of the fingers, they can often be
treated with random or axial advancement flaps. However, when they are located
in the proximal half or involve extensive defects that exceed local coverage
capacity, other reconstructive options must be considered.1-3 At
the beginning of the 20th century, Harold Gillies, a pioneer of plastic
surgery, established “the replacement of like with like” as a fundamental
principle in soft-tissue reconstruction.4 More recently, Upton et al. stated that the ideal
reconstruction of palmar defects should be performed using glabrous (hairless
and glandless), sensate, durable, relatively immobile, and thin tissues.5
The
study of cutaneous vascular territories divides the hand into digital, digitopalmar, thenar, hypothenar, and, finally, the midpalmar area (MPA). The latter, with an average surface
area of 18 cm² in adults, is densely supplied with cutaneous branches that can
be used for flap design. Within this framework, reverse and pedicled flaps from
the MPA may be considered.6 Reverse flaps are defined as those in which blood
flow is reversed through proximal pedicles or that can be rotated distally,
even without true reversal of flow direction.7
The
objectives of this study were to describe the anatomical consistency of the
cutaneous branches of the MPA, together with the palmar-dorsal and digital
anastomotic systems, and to clinically evaluate a series of patients with
finger defects treated with reverse MPA flaps.
MATERIALS AND METHODS
Anatomical Study
Five
cadaveric hands were analyzed (3 female and 2 male; mean age 70 years; range
54-80). After cannulation of the axillary artery, each specimen was injected
with red-colored latex, followed by sealing of the cannulas and preservation
using a mixture of formaldehyde and phenolic acid according to the Cozzi
technique.
Under
3.5x magnification, the palmar vasculature of the hand was dissected. The
frequency and consistency of the cutaneous branches of the MPA were analyzed,
as well as the presence of commissural arteries (communicating between the
palmar and dorsal systems) and of the proximal and distal transverse
interphalangeal arteries, also known as Edwards’ vascular arcade. Using a
micrometric caliper, the mean diameter of the cutaneous branches and palmar
vascular axes was measured, along with their angle of origin relative to the
vascular axis.
Clinical study
A
retrospective study was conducted including patients treated between January
2013 and January 2018. The inclusion criteria were: patients with palmar
digital wounds involving the four fingers, treated with reverse MPA flaps
(short or long), without age restriction, without prior surgical history, with
or without associated injuries (partial amputation of the distal phalanx or
distal interphalangeal disarticulation, digital nerve injury distal to the
Edwards arcade used as the pivot point, or tendon injury), and a minimum mean
follow-up of 24 months. Patients who did not meet these criteria or who had
infectious processes were excluded.
All
procedures were performed by a single hand surgeon in a single operative stage,
at a mean of 4 days after trauma (range 1–9). The anatomosurgical
classification proposed by Zancolli for reverse MPA
flaps was used, based on the cutaneous branches of the arteries supplying the
skin and their pivot point. This classification divides the flaps into short
and long, according to the pivot point (commissural confluence or transverse
interphalangeal artery, respectively) and their distal reach (Figures 1 and 2).6 The surgical technique is described below.
Surgical Technique
The
procedure is performed under supraclavicular plexus block, with gentle
inflation of the tourniquet. After marking the anatomical landmarks (the common
and proper digital neurovascular bundles, as well as the probable location of
cutaneous perforators in the MPA), the extent of digital tissue loss is
determined, and both the size and shape of the defect are transferred to the
skin of the MPA (according to the finger to be reconstructed).
The
first step consists of an approach at the interdigital commissure, under 3.5x
magnification, to confirm the commissural communication between the dorsal and
superficial palmar systems (common digital artery).
Once
confirmed, the skin island is designed, including an average of 2 to 4
cutaneous branches. The flap is dissected with the least possible amount of
subcutaneous tissue. The fibers of the central palmar aponeurosis are divided;
the common digital artery is dissected and ligated proximally at its junction
with the superficial palmar arch. The island flap is elevated, handling the
pedicle carefully and avoiding stretching or twisting along its axis. From the digitopalmar region, the approach is continued in a zigzag
fashion, separating the common digital artery and the bifurcation of the proper
digital arteries (with their venae comitantes) from
the common digital nerve, which is preserved and protected. Through a lateral
digital approach, dissection proceeds until reaching the defect to be covered.
The commissural confluence must be preserved (short midpalmar
area flap [MPA]) or ligated and divided together with the collateral artery of
the adjacent finger to increase advancement (long MPA). The tourniquet is
released, meticulous hemostasis is performed, and flap viability is assessed by
irrigation with warm saline solution. The recipient site is then covered with
the skin island and approximated using 4-0 monofilament sutures, avoiding
excessive tension.
Finally,
a split-thickness skin graft is harvested from the elbow crease, medial aspect
of the arm, or groin (with primary closure) to cover the donor site. An elastic
anti-edema dressing is applied, and the hand is immobilized with a short arm
plaster splint extending to the digits.
Postoperative Course
Daily
wound care was performed during the first 5 days after surgery to assess flap
viability (evaluating clinical parameters such as color and capillary refill,
without Doppler or other adjunctive methods). Subsequent wound care was
performed weekly until suture removal. The patient then began hand occupational
therapy. Time to return to usual activities (work/sports) was recorded.
Patients were contacted by telephone for long-term follow-up (12 and 24
months).
The
sample was evaluated subjectively using the visual analog scale for pain and
the QuickDASH questionnaire. Objective evaluation was
performed using the two-point discrimination test, and the Strickland scoring
system was used to assess total active range of motion by goniometry, defined
as the sum of active flexion of the metacarpo-phalangeal,
proximal interphalangeal, and distal interphalangeal joints minus the extension
deficit of these joints.6 Results >150°
were considered excellent; 125°-149°, good; 90°-124°, fair; and <90°, poor.
Secondary
complications related to the surgical procedure (partial or total necrosis,
dehiscence, retractile scarring) were recorded.
RESULTS
Anatomical Study
The
anatomical study demonstrated the consistent presence of cutaneous branches of
the MPA. An average of 2 to 4 branches per flap island designed at the
intermetacarpal level was identified in the cadaveric specimens (Figure 3). These branches emerged at an angle of
approximately 70° (range 65°-75°) relative to the common digital artery,
perforating the central palmar aponeurosis. In all specimens, a commissural
artery (communicating between the palmar and dorsal systems) was consistently
identified at the digital commissure, with a mean diameter of 0.4 mm (range
0.3-0.5) (Figure 4).
The
mean diameter of the common digital arteries was 1.9 mm (range 1.7-2.1), while
the mean diameter of the proper digital arteries was 1.1 mm (range 1-1.2).
In all
dissections, transverse interphalangeal arteries, also known as Edwards’
vascular arcade, were identified, serving an anastomotic function between the
collateral vessels of the same finger. These vessels emerged at an average
angle of 80° (range 78°-82°) relative to the proper digital artery and were
located at the neck of the proximal and middle phalanges, respectively. They
contributed to the arcade together with the articular branch of the proper
digital nerve (in two specimens, two articular branches were identified per
side) (Figure 5).
Clinical Study
A
series of 10 patients (8 male and 2 female) with a mean age of 25 years (range
6-45) was included. The non-dominant hand was affected in 80% of cases. The
most frequently involved finger was the middle finger (6 cases), followed by
the index finger (3 cases) and the ring finger (1 case). In most cases, the
injury was work-related. In two cases, neurorrhaphy of the injured proper
digital nerve was performed. In one case, partial amputation of the distal
phalanx was present, and in another, distal interphalangeal disarticulation.
The mean defect size was 15.1 x 11.3 mm. In eight cases, short MPA flaps were
performed, and in two cases, long MPA flaps were used due to the distal
location of the defect. All flaps survived.