The Z-plasty is a procedure which involves the transposition of two interdigitating triangu-lar flaps. The name derives from the ‘Z’ shape seen when the three limbs of the flaps are drawn out on the skin. Transposition of the flaps has several effects , of which two have special relevance: 1. There is a gain in length along the direction of the common limb of the Z. 2. The direction of the common limb of the Z is changed.
Exploitation of these effects has made the Z-plasty an extremely useful and widely used procedure. Its value has been most strikingly established in three sets of circumstances: in the treatment of contracted scars, when use is made of the gain in length, in the management of facial scars, when use is made of the change in direction of the common limb, and in the prevention of scar contracture in certain types of elective and emergency surgery, particularly in the hand.
Lengthening and change of direction of the common limb occur together as a result of transposition, but it is usually only one of the two which concerns the surgeon at any particu-lar time. The fact that the other is accomplished at the same time is usually a bonus, though it can be a nuisance.
The Z-plasty was originally used in releasing contracted scars, and its theoretical basis can be more easily understood if it is considered with that as the background.