This document provides information about syndactyly, including its definition, embryology, etiology, types, evaluation, management, surgical techniques, complications, and its association with certain genetic syndromes. Syndactyly is a fusion of soft tissue or skeletal elements of adjacent digits. It occurs when normal digital separation fails during development. Surgical correction aims to separate the digits and reconstruct the intervening skin and tissues. Timing, flap design, and postoperative care require consideration to optimize outcomes and prevent contractures. Syndactyly can be an isolated anomaly or part of genetic syndromes like Apert syndrome or Poland syndrome.

1. Syndactyly
Dr Kushal Shah

5. Definition and embryology
• Its a variable fusion of the soft tissue or skeletal elements or both
of adjacent digits, and it occurs when the normal processes of
digital separation and web space formation fail to some degree.(
figure 1)
• Normally digits form as condensations of mesoderm within the
terminal paddle of the embryonic upper limb. Spaces form between
the fingers in a distal to proximal direction to the level of the normal
we space by a process of regulated apoptosis which is dependent
on the apical ectodermal ridge ( AER) and the molecular
signaling
• The normal web space slopes 45 degrees in a dorsal to palmar
direction from the metacarpal heads to the midproximal phalanx
(Figure 2).
• The second and fourth webs are wider than the third web, allowing
greater abduction of the index and small fingers.
• The first web space is a broader diamond-shaped expanse of skin
composed of the glabrous skin of the palm and thinner mobile skin
dorsally

6. Etiology
• Are fairly common and often run in families
• Occur in about one out of every 2,500-3,000 newborns
• Affect boys more often than girls( 2:1)
• Affect whites more often than blacks or Asians
• Bilateral about 50 % of the time
• Can occur alone or as part of a genetic syndrome, such as
Apert syndrome
• Can sometimes be seen prior to birth by ultrasound

7. Ray involvement
• 50% long-ring finger
• 30% ring-small finger
• 15% index-long finger
• 5% thumb-index finger

8. type

9. Pre op evaluation
• which web space(s) is involved
• the extent of the syndactyly
• the involvement of the nail
• and the presence of other anomalies.
• Lack of differential motion between the digits may indicate bony fusion or an
extra digit, or both, concealed within the conjoined digits.
• Examine entire upper limb, the contralateral hand, the chest wall, and the feet.
• Radiographs may reveal skeletal fusion, a concealed extra digit
(synpolydactyly), or other bony or articular deformities.
• Further imaging with ultrasound or magnetic resonance imaging can be useful
in determining the flexor tendon and Vascular anatomy in complex cases

10. Management
• Syndactyly can have cosmetic, functional, or
developmental impacts on the growing child.
• The appearance of the hand is altered, more so
with complete complicated forms of syndactyly.
• Syndactyly of the first web space hampers grasp
and the development of pinch.
• Syndactyly of the second, third, and fourth web
spaces inhibits independent digital motion,
particularly abduction, and therefore reduces the
span of the hand.
• Syndactyly between digits of unequal length
causes tethering of the longer digit, which
deviates toward the shorter digits and may also
cause a flexion contracture at the proximal
interphalangeal joint (PIP) that progresses with

11. Surgical contra indication
• include mild incomplete
syndactyly without functional
impairment
• medical conditions that preclude
surgery, or complex
• syndactylies that risk further
functional impairment with
attempted separation.
• In complicated complex – there
are insufficient components in the
fused mass to produce
independent, stable, and mobile
digits .
• This situation typically arises in
central brachysyndactyly or
synpolydactyly, and separation
risks reducing function.

12. Surgical factors to be taken into account
• timing of the procedure or procedures
• staging the releases of multiple web space
syndactylies
• creation of a commissure
• techniques of separation and resurfacing of the
digits
• postoperative dressing and aftercare.

13. Timing of surgery
• Syndactyly release has been performed in the neonatal period or
during infancy, or it has been delayed until childhood.
• Longterm reviews by Flatt and Ger have shown better outcomes
with release after 18 months, although early surgery may be
dictated by progressive skeletal deviation or deformity.
• The goal is to complete all the releases by school age
• . In multiple staged release - the first procedure can be combined
with isolated release of the fingertips and distal phalangeal fusions
of all the digits to reduce the tethering effect between surgical
procedures

14. Surgical anatomy
• cleeland's ligament:
- coalesce in interdigital space
forming a dorsal roof over digital vessels and
nerves as well as forming a septum between
them;
- digital nerves and arteries may not be
available for both digits;
- vessels may be entwined, or
absent w/ in the bridge;
- aberent anatomy is more common
w/ more complex deformities;
- nerves should be teased apart
using magnification;

15. Surgical steps
• (1) separation of the digits
• (2) commissure reconstruction
• (3) resurfacing of the intervening borders of
the digits.
• (4) Paronyhcial fold formation

16. Seperation of digits
• Release of syndactyly requires
careful planning to optimize use of
the available skin and to allow
surgical exposure for separation of
digits and structures.
• Separation of the digits requires
division or excision of fascial
interconnections between the digits,
with care taken to identify and
preserve the individual
neurovascular bundles and the
venous plexus on the dorsum of the
digits and of the commissure flap
• . Bifurcation of the common digital
nerve and artery may be distal to
the planned position of the web
space.
• In this situation, the digital artery
can be ligated provided the other
side of the digit is unoperated or the
contralateral digital artery is known
to be intact
Cronin and Skoog
–dorsal and volar
triangular flap
with matched zig
zag incision
Somarlad open
finger technique

17. Different skin incision technique depicted below

18. Commissure reconstruction
• A basic tenet of syndactyly
release is reconstruction of the
interdigital commissure with a
local skin flap.
• Incision design must be placed
such that inevitable scar
contraction will avoid joint or
web space contracture
• For 1st web space: Other
options include a transposition
flap from the index finger, a
combination of transposition
flaps from the radial and ulnar
borders of the index and thumb,
respectively, or a “V-to-Y”
advancement of the central
web.
Butterfly flap for
web deepening
4 flap Z
plasty
for1stweb
space

19. Resurfacing of the digit
• Resurfacing the digits is achieved with the
palmar and dorsal flaps raised from the
conjoined digits supplemented with skin
grafts.
• Full-thickness skin grafts are preferred
over split thickness skin grafts to lessen
secondary graft contracture
• Resurfacing the digits without skin graft
may require some reduction of digital
diameter by excising the subcutaneous fat
of the digit while preserving the dorsal
venous system

20. Graftless syndactyly release technique

21. Paronychial fold formation
• Release of a complete
syndactyly, particularly when
associated with distal
phalangeal fusion, requires
the formation of a paronychial
fold.
• The distal phalangeal tufts
may be covered using the
technique described by
Buck-Gramcko.
• Laterally based long narrow
triangular flaps are raised
from the hyponychium of the
conjoined digital mass and
folded around to form the
lateral nail fold

22. Post operative dressing
• The dressings must apply gentle compression across the
skin graft sites and protect the separated digits.
• Nonadherent dressings and moist cotton are placed into the
web spaces and reinforced with large amounts of soft gauze.
• In young children, the compressive hand dressing is
reinforced by above-the elbow plaster or a soft cast to
prevent inadvertent removal.
• The elbow is positioned in at least 90 degrees of flexion to
minimize the chances of the cast sliding off the arm.
• The dressings are removed 3 weeks after surgery, and then
gentle washing and wound care are needed. The wounds are
protected until they are dry and healed.
• Normal hand use is allowed after the dressing has been
removed.
• Once healing has taken place, an elasticized compression
glove may be fitted and worn for up to 3 months for scar
management.
• Scar massage by oil/gel , silicone gel sheets, or elastomere
products can be used to treat areas of hypertrophic scarring.

23. Complication
• Early :vascular
compromise,
infection, wound
dehiscence, and
graft loss.
• Late : web creep,
Joint contractures,
beaked nail
deformity

28. Syndactyly : and its associated syndrome
• Acrosyndactyly
Poland's syndrome:
- hypoplasia of hand and simple syndactyly of fingers on the same side as
the absent pectoral muscles (and other chest wall muscles);
- Apert's Syndrome:
- when all digits are joined, as is common in spoon hand of
Apert's syndrome (acrocephalosyndactyly), it is important to release border
digits-thumb and small finger-first;
- remaining 3 joined fingers can be managed by removing middle digit, thus
creating a three-fingered hand with a thumb and sufficient
skin for closure;
- Chromosomal Syndromes:
- trisomy of 13, 18, or 21;
- deletion of short arm of chromsome 5;
- Craniofacial Syndromes:
- Aglossia adactylia
- Mobius Syndrome
- Oculomandibulofacial syndrome

29. Acrosyndactyly:
• Classification:
- Type I:
- conjoined finger tips with well formed webs w/ normal
depth;
- treatment involves separation and contouring of the tips
of the digits;
- partial digit ablation may be required;
- Type II:
- tips of digits are joined and web formation is incomplete;
- treatment involves separation of tips of digits and
deepening of web space;
- Type III:
- absent web spaces, sinus tracts, joined digit clefts;
- as in simple syndactyly border digits are reconstructed
first
•

30. Apert syndrome
• Acrocephalosyndactyly – craniosynostosis with acrosyndactyly and
symphalangism and clinodactyly of thumb
• M:F – 1.5:1
• AD/AR
• 1:2,00,000
• Single gene mutation

31. Upton classified into I spade , mitten and
rosebud appearance respectivity Type 1-3

34. Radial thumb clinodactyly
• Dao recommended a release of the
abnormal abductor pollicis brevis
tendon insertion into the distal
phalanx and reinsertion the proximal
phalanx, excision of the metacarpal
head ulnar prominence, and pinning
of the interphalangeal and
metacarpophalangeal joints.
• Oishi and Ezaki proposed that the
thumb be reconstructed by releasing
the abnormal abductor pollicis
brevis insertion, opening or closing
wedge osteotomy of the proximal
phalanx, and a V-Y advancement
flap on the radial side of the thumb.

35. First web space release

36. THANK YOU