EditorialTG (Tri-Goniometry) technique: Obtaining perfect angles in Z-plasty planning with a simple ruler
Introduction
The Z-plasty is used frequently in plastic surgery to improve contractures, especially due to burn scars. This procedure, which involves the transposition of corresponding triangular flaps, can either elongate a contracture band in the skin or decrease scar tension.
The basic variable in Z-plasty flaps is the angle. Classically, angles of 30, 45, 60, 75, and 90° are used. These angles are important when elongating a contracture line or decreasing tension. For example, a contracture line can be elongated by 50% using a Z-plasty performed with a 45° angle; the amount can be increased to 75% with a procedure performed using a 60° angle.
Many Z-plasty options have been reported, including the classical Z-plasty, double opposing Z-plasty, and four-, five-, and six-flap Z-plasties.
In all of these methods, it is important that the angles of the flaps be calculated correctly. Although many methods have been proposed for this purpose, all require angle-measuring equipment [1].
Our method uses only trigonometry coefficients and a simple ruler, which is easily obtained and sterilized, enabling surgeons to perform all types of Z-plasty without measuring angles using a goniometer.
Section snippets
Technique
In this technique, the corner angles of a simple ruler are used to draw right angles. The other angles are constructed using simple virtual axes. The limbs of the Z-plasty are considered the hypotenuse, and simple sine and cosine values are calculated from the hypotenuse during planning. In the following procedures the contracture band has a length of x.
Discussion
Correct angles and equalization of each limb are the most important parts of the Z-plasty technique, which is commonly used when releasing burn scar contractures or revising scars [2]. A simple ruler is enough for equalization of limb but a goniometer is needed for accuracy and equalization of angles.
Many methods have been used to calculate angles, but most require a goniometer [3]. Classically, a 30° angle can be obtained by dividing the 90° angle formed by drawing a line perpendicular to the
Funding
None declared.
Conflicts of interest
The authors have no conflict of interest to disclose for this study.
Ethical approval
Not required.
References (3)
Z-plasty template: an innovation in Z-plasty fashioning
Plast Reconstr Surg
(1996)
Cited by (2)
Z-Plasty Flap and Its Variants
2022, Soft Tissue Reconstruction of the Hand: Loco-regional and Distant Flaps Selection and ApproachZ-plasty as an alternative choice for the treatment of recurrent local sternal wound infections
2019, General Thoracic and Cardiovascular Surgery