From the Research
A Z-plasty at 45 degrees increases scar length by approximately 50%. When performing a Z-plasty, the original scar is converted into a Z-shaped incision with two lateral limbs at 45-degree angles to the central limb. After transposition of the triangular flaps, the final scar length is about 1.5 times the original length. This lengthening effect is directly related to the angle used - smaller angles produce less lengthening while larger angles (up to 60 or 75 degrees) can increase length by 75-100% 1. The mathematical basis for this relationship follows trigonometric principles, where the final length equals the original length multiplied by the cosecant of half the angle.
The lengthening effect is crucial for releasing contractures and redistributing tension along the scar, which improves both functional and aesthetic outcomes. Surgeons select the appropriate angle based on the specific needs of each case, balancing the desired lengthening effect with tissue availability and anatomical constraints. Some studies have reported variations of the Z-plasty technique, such as the reversed Z-plasty, which can be effective for wide-scar contractures 2. However, the basic principle of the Z-plasty remains the same, and the choice of angle depends on the specific requirements of the case.
Key points to consider when performing a Z-plasty include:
- The angle of the Z-plasty determines the amount of lengthening achieved
- Smaller angles produce less lengthening, while larger angles produce more lengthening
- The mathematical basis for the lengthening effect follows trigonometric principles
- The choice of angle depends on the specific needs of the case, balancing lengthening effect with tissue availability and anatomical constraints
- Variations of the Z-plasty technique, such as the reversed Z-plasty, can be effective for specific types of scars 3, 4.