Successfully exploiting two opposing forces: a rational explanation for the "interlocking suture".

[BACKGROUND] Issues of poor circumareolar scars and asymmetry or malposition of the nipple-areola complex (NAC) are frequently associated with those breast reduction or pexy techniques that rely on an ample excision of skin around the areola, either alone or associated with a vertical scar in a circumvertical approach. To prevent such problems, in 2007 Hammond et al. introduced the "interlocking suture." The objective of this study was to demonstrate the true ability of this suture to reduce the common complications of periareolar surgery simply by managing the existing contrast between NAC centripetal and outer breast tegument centrifugal forces.

[METHODS] By using finite element method (FEM) software, the NAC traditional interrupted stitches were compared with both round-block and interlocking sutures, and the skin strain in all three procedures was qualified.

[RESULTS] The contribution of circuitous stitches in the interlocking suture leads to a more advantageous distribution of forces. FEM analysis shows that the interlocking suture reduces skin stress on peripheral breast teguments by 14% compared to the round-block suture and by 15% compared to the traditional (radial) suture. When evaluating the areolar edge, the interlocking suture leads to a reduction in skin stress of 9.9% compared with traditional interrupted stitches.

[CONCLUSIONS] The efficient, long-lasting results of the interlocking suture are directly due to its unique design, which effectively reduces the tension between the NAC and breast tegument edges in periareolar surgery, thus improving the quality of the scar.