Biogeometry of transposition flap

what is transposition flap and how to mark it

1. Biogeometry of Transposition flap By- Dr Reshma Gopakumar

2. What is B io-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

10. 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 .

11. 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.

12. 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.

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

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

15. 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 2 nd stage Used when the nearby skin to the defect has less mobility while the neighboring skin to that has mobility.