Keywords
clinodactyly - figers/abnormalities - surgical flaps - osteotomy
Introduction
Clinodactyly is a congenital hand deformity that is characterized by coronal angular
deviation and may occur in thumbs or fingers; little finger deformity is frequent
and often mild, as an isolated deformity. Angulations in excess of 20o create functional changes with digit overlapping during flexion.[1]
[2]
[3]
[4] The thumb deformities are more often severe and can be associated with syndromes,
such as Rubstein-Taybi, Pfeiffer, Apert, and Patau, among others.[1]
[2]
[3]
[4] In most cases, there is a radial deviation; such deformities are also called “hitchhiker's
thumb.”[5]
Severe angulations commonly show the replacement of a normal phalanx for another with
an abnormal format, which can be triangular or trapezoid-shaped. Surgical treatment
is indicated for those patients; one of the options consists of bone alignment by
means of an addition wedge osteotomy of the abnormal phalanx and K-wire fixation.[6] Such alignment maneuver creates a problem in skin cover and soft-tissue tension
at the concave aspect of the deformity. Thus, some sort of skin flap is needed for
adequate closure of the operative wound.[7]
The use of a bilobed flap, as described by Esser,[8] and further modifications[9] allow skin redistribution, taking the redundant skin of the convex aspect to the
concave aspect of the deformity. Such technique allows digit alignment without the
need of either skin grafting or distant flaps.
The present study aims to detail the technique for the bilobed flap in the surgical
treatment of clinodactyly, as described by Cerqueiro-Mosquera and Fleming[5] in 2000, and to assess the results of a series comprising 9 digits and 5 patients.
Material and Methods
The project was submitted to the institution's Research Ethics Committee, with the
number CAAE 87964217.4.0000.5335.
We retrospectively assessed all patients surgically treated at our service for clinodactyly
with bilobed flap between January 2008 and January 2015. Five patients, comprising
nine digits operated, were included in this study.
The surgical technique was indicated only for digit angular deviations ˃ 30o. Patients with thumb deformities, as well as those with deformities associated with
syndromes, were not excluded from the study. Orthopedic abnormalities associated with
other digits, such as syndactyly, were not excluded either.
The procedure was performed under general anesthesia, with the application of an upper
limb pneumatic tourniquet. Regarding the surgical technique employed, it started with
the incision design, which should be routinely performed to attain a safer primary
closure. The incision creation starts with a transverse line at the point of maximum
deformity at the digit concave aspect and aligned with the interphalangeal extension
crease. Such incision starts at the junction between the dorsal skin and the glabrous
skin (hairless) going toward the flap's dorsal lobe. The width of the dorsal lobe
should fill the size of the space that will be created at the concave aspect upon
digit alignment. The dorsal lobe extends distally from the interphalangeal extension
crease to two-thirds of the nail crease distance. The secondary lobe must be performed
toward the palm, at the convex side of the deformity, and shall have a height similar
to that of the same lobe, although not as wide ([Fig. 1]).
Fig. 1 Schematic of surgical treatment for clinodactyly using bilobed flap. It starts with
a transverse line at the digit concave border, which is the point of maximum deformity.
The dorsal lobe shall be the size of the space created at the concave border with
the digit aligned. The secondary lobe should be performed toward the palm on the convex
side of deformity and must have a similar height to that of the first lobe, although
not as wide.
Care must be taken during dorsal dissection to keep the tenosynovial tissue of the
extensor apparatus intact, along with main dorsal veins. Flap lobes include skin and
subcutaneous tissue, and care must be exercised at the convex aspect of the secondary
lobe to keep the neurovascular bundle untouched in its position.
The incision that is created for the bilobed flap is wide enough so that the anomalous
delta or trapezoidal phalanx is visualized through both sides of the extensor tendon,
thus facilitating the osteotomy. The osteotomy is transversely performed at the phalanx,
so that the deformity correction creates an opening wedge at the deformity concave
aspect. After the osteotomy, the phalanx is fixated with one or two K-wires. Bone
grafting was not employed in our series.
Flap lobes are rotated in 90o for closure, so that the dorsal lobe closes the defect on the concave aspect, and
the secondary convex lobe covers the dorsal defect. The convex aspect is primarily
closed, with no tension or need for skin grafting. Before flaps closure, the pneumatic
tourniquet is deflated for hemostasis. The patient is initially immobilized with a
long-arm plaster that includes the operated digit, which, after the first week, is
replaced by an aluminum finger splint. K-wires are removed after 8 weeks. Home mobilization
exercises are prescribed after and are usually enough for mobility recovery. Cosmetic
and functional outcomes with this technique are excellent, and do not give rise to
complications.
Results
Among the five patients included in our series, one had Apert syndrome; one had Pfeiffer
syndrome ([Fig. 2]); two had Rubinstein-Taybi syndrome—they were homozygous twins; and one had an isolated
clinodactyly ([Figs. 3] and [4]). All patients were male and had a mean age of 4 years and 1 month (ranging from
2 years and 5 months to 7 years and 4 months) at the time of the operation. Overall,
nine digits were operated, including eight thumbs and one index finger. All patients
displayed radial deviation, and the mean angle was 67.2o (ranging from 60–80o). Patients were clinically followed at a mean of 18.6 months (range: 12–24 months).
Being a pediatric patient sample, no dominance was determined at the time of the surgery
([Table 1]).
Table 1
|
Patient
|
Age
|
Sex
|
Side
|
Diagnosis
|
Site
|
Associated hand lesion
|
Initial angulation
|
Healing
|
Cosmesis
|
Complication
|
|
1
|
7y 4 mos
|
M
|
R
|
Apert syndrome
|
Thumb
|
Syndactyly 2/3/4/5 digits
|
60
|
3 weeks
|
Good
|
No
|
|
1
|
7y 4 mos
|
M
|
L
|
Apert syndrome
|
Thumb
|
Syndactyly 2/3/4/5 digits
|
50
|
3 weeks
|
Good
|
No
|
|
2
|
2y 10 mos
|
M
|
R
|
Pfeiffer syndrome
|
Thumb
|
Syndactyly 2/3/4/5 digits
|
80
|
2 weeks
|
Good
|
Flap vascular compromise
|
|
2
|
3y 11 mos
|
M
|
L
|
Pfeiffer syndrome
|
Thumb
|
Syndactyly 2/3/4/5 digits
|
75
|
4 weeks
|
Excellent
|
No
|
|
3
|
2y 11 mos
|
M
|
R
|
Rubinstein-Taybi syndrome
|
Thumb
|
No
|
75
|
2 weeks
|
Good
|
No
|
|
3
|
2y 11 mos
|
M
|
L
|
Rubinstein-Taybi syndrome
|
Thumb
|
No
|
65
|
2 weeks
|
Excellent
|
No
|
|
4
|
2y 5 mos
|
M
|
L
|
Isolated lesion
|
Index finger
|
No
|
70
|
2 weeks
|
Excellent
|
No
|
|
5
|
3y 10 mos
|
M
|
R
|
Rubinstein-Taybi syndrome
|
Thumb
|
No
|
70
|
3 weeks
|
Good
|
No
|
|
5
|
3y 10 mos
|
M
|
L
|
Rubinstein-Taybi syndrome
|
Thumb
|
No
|
60
|
3 weeks
|
Good
|
No
|
Fig. 2 Patient with Pfeiffer syndrome presenting bilateral hand changes, with the typical
hitchhiker thumb deformity associated with third- and fourth-digit syndactyly (A).
Radiograph showing a delta proximal phalanx of the thumb, and hypoplasia of middle
phalanges of long fingers (B). Thumb radiograph details clinodactyly and delta phalanx
(C). Surgical planning with bilobed skin flap (D). Elevation and rotation of bilobed
flap with complete skin cover (E and F).
Fig. 3 Patient with index finger clinodactyly. An isolated deformity not associated to any
syndrome (A). Radiograph proves the abnormal development of middle phalanx. Delta
phalanx (B). Surgical planning with bilobed skin flap (C and D).
Fig. 4 Same patient of the previous figure. Elevation and rotation of bilobed flap, with
complete skin cover (A, B, and C). Delta phalanx osteotomy and K-wire fixation (D).
Skin healing after 2 weeks postoperatively (E and F).
There were no severe perioperative or early postoperative complications as regard
to the technique. The procedure conveyed the primary closure of all operated digits.
All nine digits had the flap healed at 18.6 days (ranging from 14–28 days). All flaps
endured, and only one patient showed a distal compromise of part of the first lobe.
In this case, a crust formed, followed by second-intention healing.
Three patients with bilateral deformity had both hands operated on the same day. Only
one patient with bilateral thumb deformity was operated in two steps due to third-
and fourth-digit syndactyly, which was conjointly approached with the thumb clinodactyly.
No patient required a second procedure. All patients presented good or excellent cosmesis,
and no deformity relapses were seen at a minimum of 12-months follow-up. Upon subjective
assessment, all patients and families reported to be satisfied with the surgical outcome.
Discussion
Clinodactyly is a congenital anomaly featured by an excessive lateral deviation of
a digit. In long fingers, that usually occurs due to abnormal medium phalanx development,
leading to distal interphalangeal joint deformity, and, exceptionally, it can lead
to proximal interphalangeal joint deviation due to a proximal phalanx abnormality.[1]
[2]
[3]
[4] It is most frequently caused by a delta phalanx, which is defined by its triangular
shape, with a longitudinal epiphysis instead of a transverse one, located on the shorter
side of the phalanx. The abnormal epiphysis disturbs the bone growth, thus causing
a staple-like effect. Delta phalanges display a circle- or D-format on radiographs.
A progressive, lateral deviation of the finger occurs with growth.[2]
[6]
The most frequent site is the fifth digit with a radial-sided deformity, and, most
commonly, there is bilateral compromise. Those cases usually show a positive familial
history due to a variable expressivity, autosomal dominant trait. The second most-frequent
location is the index finger, showing ulnar or radial deviation. Surgical procedures
are indicated for severe angulations and functional changes, causing finger overlapping
during flexion, which usually happens with angulations ˃ 30o.[2]
[3]
[10]
The treatment for hitchhiker's thumb is the same used for the delta phalanx.[11] Few studies have assessed the result of surgical treatment of thumb clinodactyly,
and mostly have reported a deformity recurrence in excess of 30% of the patients.[11]
Our series thus included patients with Apert Syndrome, whose thumbs are always short
and radially deviated; Pfeiffer Syndrome, whose hands are affected in almost 80% of
cases, and changes are quite variable. Only 20% of patients with this syndrome display
the hitchhiker thumb typical deformity. The other syndrome found in our series was
the Rubinstein-Taybi Syndrome, a rare dysmorphic pathology described in 1963.[12]
[13] The hand shows an enlarged and radially-deviated thumb, due to the presence of a
delta proximal phalanx, thus creating the hitchhiker thumb.
Clinodactyly has been classified by Burke and Flatt.[14] Ali et al.[4] have classified in accordance to deformity severity.
No matter the cause, the corrective surgery for clinodactyly aims to improve function
and cosmesis. Different surgical procedures have been described, and the choice of
technique depends on the underlying pathology, deformity degree, soft-tissue contracture,
age, and surgeon preference. The procedure shall address bone alignment, soft-tissue
lengthening, and skin cover.[1]
[7]
Different bone procedures have been proposed. Burke and Flatt[14] described resection, or closing-wedge osteotomy, a simpler procedure that carries
the pitfall of the creation of a shortening on an already shortened digit. Carstam
and Theander[15] advocate an inversion-wedge osteotomy, in which a wedge is removed from one side
of the phalanx and placed on the other side. Vickers[7] proposes a physeal opening through a mediolateral incision at the deformity apex,
and fat interposition for the early treatment of clinodactyly. The deformity is, thus,
not corrected during the surgery, but during longitudinal bone growth. It is not indicated
for patients ˃ 10 years of age and those with thumb deformities. Jain et al.[16] have employed a dome-shaped osteotomy in 8 of 13 patients operated and reported
angular deformity recurrence in 5 patients. Jones[17] described an addition- or opening-wedge osteotomy, with the advantage of creating
a larger digit, together with bone and soft-tissue lengthening, along with skin cover
by means of a z-plasty or full-thickness bone graft. Al Qattan[18] points the use of Vickers' procedure for early treatment, and addition-wedge osteotomy
for older patients and more severe deformities. Other techniques described, such as
simple fixation with K-wires, primary arthrodesis, and isolated capsulotomy have all
been abandoned due to poor results.
The alignment of a digit severe angular deformity requires a concurrent care with
skin cover, especially in cases of addition-wedge osteotomy. The need of soft-tissue
release at the concave side of deformity may appear during the procedure. Collateral
ligaments and joint capsule may be released or lengthened, thus allowing the correct
digit positioning.[6] Several different flaps have been described, and the aim is the rapid healing with
good-quality skin, minimum scarring, and the lack of need for a distant skin graft
or flap rotation.[4] Z-plasties may produce a satisfactory skin cover for cases of resection-wedge osteotomy.[13]
The bilobed flap was originally described by Esser in 1918,[8] and, due to its versatility, it has been employed for defect reconstruction in different
anatomic regions. The use on the correction of radial tilt hand deformity[12] and skin cover for distal interphalangeal joint mucous cyst postcorrection[19]
[20] has been described. The angle between flap lobes was originally described as of
90o; however, several authors have created use and shape variations, thus allowing the
possibility of angle variation between 45 and 180o, depending on the application.[20]
[21] Our series has followed the technique as proposed by Cerqueira-Mosqueira and Fleming,[5] using the bilobed flap to aid in clinodactyly reconstructions. This flap is obtained
in a simple, safe fashion, and takes advantage of the redundant skin from one given
region, adding quality skin cover on another region. The geometric design is straightforward
and reproducible, thus minimizing the learning curve. The cosmetic result of the scar
was excellent, as the flap allows skin closure with no tension.
The bilobed flap has clear advantages over other techniques for skin redistribution
in angular defects. Due to creation simplicity and potential use of local redundant
skin. It is a safe procedure, allowing adequate skin cover during surgery, with no
tension onto the suture, thus avoiding the need of skin grafting or second-intension
healing. Its simple geometric shape conveys reliability, allowing a rapid, unique,
and definitive procedure. The final cosmetic result was excellent, expediting the
healing process.[5]
[20] It is hard to find a surgeon with at least reasonable experience in the treatment
of hand clinodactyly, for its rareness. We have performed the bilobed flap in patients
with different syndromes with good results, especially in diseases prone to develop
keloid scarring.[13] Patients showed good or excellent cosmetic evolution. There was no deformity recurrence
within a follow-up of at least 12 months. We regard this follow-up time as too short
to define whether there will be any residual deformity; however, such type of assessment
was the chosen option, because the emphasis of this study is on the skin flap technique.
