Biodynamic Excisional Skin Tension Lines for Excisional Surgery of the Lower Limb and the Technique of Using Parallel Relaxing Incisions to Further Reduce Wound Tension

Background: Closing of defects of the lower limb after skin cancer excision poses a challenge in lower limb skin. Although the concept of relaxed skin tension lines has been established as ideal on the face, on the lower limb there remains confusion between Langer's lines and wrinkle lines, and this study was done with the task of identifying and mapping biodynamic excisional skin tension (BEST) lines on the lower limb. Methods: Following studies on BEST lines elsewhere on the body, the author investigated BEST lines on the lower limb. Using a specially designed tensiometer, inherent skin tension (pretension) and wound-closing tension were studied along with the force needed to bring the wound edges together after excision of a lesion in 23 cases with defects ranging from 1.5 to 4.5 cm in diameter. Skin tension measurements of skin lines (relaxed skin tension lines (RSTL) versus BEST) and vertical closure (BEST) versus vertical closure with a parallel relaxing incision were undertaken and followed by statistical analyses utilizing the paired t test and the unpaired Student's t tests. Results: BEST lines run in the vertical direction on the lower limb, that is, closure in a vertical direction resulted in a statistically significant reduction in closing tension when compared with other directions. Using a parallel relaxing incision can offer further reduction in tension, if needed. Conclusion: BEST lines of the lower limb are discussed, and a new technique of using parallel relaxing incisions to achieve closure of larger defects is also presented as an alternative to cutaneous flaps or grafts in the lower limb.