This document discusses the biogeometry of transposition flaps. It defines biogeometry as the integration of biological and geometric factors that govern efficient flap selection, siting, design, construction, and transfer. A transposition flap involves moving a rectangle, triangle, or square of skin and tissue from one area to an adjacent defect using a pivot point. Classic flap designs close the donor site with a skin graft, direct suturing, or a secondary flap. Variations include the Limberg, bilobed, note, sliding, and interpolation flaps as well as Z-plasty and rhombic flaps. The classic flap geometry uses an isosceles or right triangle to triangulate the defect. Adv

1. BIOGEOMETRY OF
TRANSPOSITION FLAP
By- Dr Reshma Gopakumar

2. What is Bio-geometry ?
 Integration of BIOLOGICAL and
GEOMETRICAL factors that govern the logic
involved in efficient
 Selection
 Siting
 Design
 Construction &
 Transfer of a flap.

3. What is transposition flap ?
 It is a rectangle / triangle / square of skin and
subcutaneous tissue that moves about a pivot
point into an immediately adjacent defects.
 The flap donor site is closed by skin grafting,
direct suturing of the wound or a secondary
flap from the most lax skin at right angles to
the primary flap.

4. Classic flap design – donor
site closed with ssg

5. Limberg – another variation- donor
site closed by suturing

6. Bilobed flap – a variation – donor site
closed by another flap

7. Modification of flap
 Note flap *
 Sliding transposition flap *
 Interpolation flap*
 Rhombic flaps
 Z- plasty
 Bilobed

8. The classic flap geometry
Triangulating the defect:
 Isosceles triangle
 Right angle triangle
Selection depends on the orientation of the
soft tissues.The more angled the flap is
from the defect, the right angled triangle
is ideal as the flap has to move less.

9.  II. Marking of the Pivot point
 III. Flap marked.
 Jack knife like lateral movement

21. Advantage of the flap
 Local flap
 Easy technique
 Redistribution and redirection of tension.
 They tend to be smaller in size than
advancement and rotation flaps.

22. Disadvantage of the flap
 In classic pattern, the donor site can’t be
closed primarily – needs grafting
 Dog earing when one side of the flap is much
shorter than the other.

23. Note flap
 Transposition flap designed as
a triangle with 50-60 degree
angle used to close an
adjacent circular defect.
 Resembles a musical eight
note
 To close circular defect upto 2
cm in size anywhere on the
head and neck.

24.  The adjacent limb of the flap 1.5 times
diameter of the defect and parallel to a
Relaxed SkinTension Lines.
 The second limb of the flap is equal to the
diameter of the defect.
 The donor site is closed primarly.

26. Sliding transposition flap
 It’s a modification
where the defect is not
triangulated
 Its made eliptical
 The flap doesn’t extend
beyond the ellipse.

28. Interpolation flap
 Type of 2 stage tissue flap
 The base of flap is not adjacent to the defect
 Bridge of tissue present between flap base and
the defect.
 The skin island has to be removed in 2nd stage

 Used when the nearby skin to the defect has less
mobility while the neighboring skin to that has
mobility.